1 // SPDX-License-Identifier: GPL-2.0-only
2 /*
3  *  Security-Enhanced Linux (SELinux) security module
4  *
5  *  This file contains the SELinux hook function implementations.
6  *
7  *  Authors:  Stephen Smalley, <stephen.smalley.work@gmail.com>
8  *	      Chris Vance, <cvance@nai.com>
9  *	      Wayne Salamon, <wsalamon@nai.com>
10  *	      James Morris <jmorris@redhat.com>
11  *
12  *  Copyright (C) 2001,2002 Networks Associates Technology, Inc.
13  *  Copyright (C) 2003-2008 Red Hat, Inc., James Morris <jmorris@redhat.com>
14  *					   Eric Paris <eparis@redhat.com>
15  *  Copyright (C) 2004-2005 Trusted Computer Solutions, Inc.
16  *			    <dgoeddel@trustedcs.com>
17  *  Copyright (C) 2006, 2007, 2009 Hewlett-Packard Development Company, L.P.
18  *	Paul Moore <paul@paul-moore.com>
19  *  Copyright (C) 2007 Hitachi Software Engineering Co., Ltd.
20  *		       Yuichi Nakamura <ynakam@hitachisoft.jp>
21  *  Copyright (C) 2016 Mellanox Technologies
22  */
23 
24 #include <linux/init.h>
25 #include <linux/kd.h>
26 #include <linux/kernel.h>
27 #include <linux/kernel_read_file.h>
28 #include <linux/errno.h>
29 #include <linux/sched/signal.h>
30 #include <linux/sched/task.h>
31 #include <linux/lsm_hooks.h>
32 #include <linux/xattr.h>
33 #include <linux/capability.h>
34 #include <linux/unistd.h>
35 #include <linux/mm.h>
36 #include <linux/mman.h>
37 #include <linux/slab.h>
38 #include <linux/pagemap.h>
39 #include <linux/proc_fs.h>
40 #include <linux/swap.h>
41 #include <linux/spinlock.h>
42 #include <linux/syscalls.h>
43 #include <linux/dcache.h>
44 #include <linux/file.h>
45 #include <linux/fdtable.h>
46 #include <linux/namei.h>
47 #include <linux/mount.h>
48 #include <linux/fs_context.h>
49 #include <linux/fs_parser.h>
50 #include <linux/netfilter_ipv4.h>
51 #include <linux/netfilter_ipv6.h>
52 #include <linux/tty.h>
53 #include <net/icmp.h>
54 #include <net/ip.h>		/* for local_port_range[] */
55 #include <net/tcp.h>		/* struct or_callable used in sock_rcv_skb */
56 #include <net/inet_connection_sock.h>
57 #include <net/net_namespace.h>
58 #include <net/netlabel.h>
59 #include <linux/uaccess.h>
60 #include <asm/ioctls.h>
61 #include <linux/atomic.h>
62 #include <linux/bitops.h>
63 #include <linux/interrupt.h>
64 #include <linux/netdevice.h>	/* for network interface checks */
65 #include <net/netlink.h>
66 #include <linux/tcp.h>
67 #include <linux/udp.h>
68 #include <linux/dccp.h>
69 #include <linux/sctp.h>
70 #include <net/sctp/structs.h>
71 #include <linux/quota.h>
72 #include <linux/un.h>		/* for Unix socket types */
73 #include <net/af_unix.h>	/* for Unix socket types */
74 #include <linux/parser.h>
75 #include <linux/nfs_mount.h>
76 #include <net/ipv6.h>
77 #include <linux/hugetlb.h>
78 #include <linux/personality.h>
79 #include <linux/audit.h>
80 #include <linux/string.h>
81 #include <linux/mutex.h>
82 #include <linux/posix-timers.h>
83 #include <linux/syslog.h>
84 #include <linux/user_namespace.h>
85 #include <linux/export.h>
86 #include <linux/msg.h>
87 #include <linux/shm.h>
88 #include <uapi/linux/shm.h>
89 #include <linux/bpf.h>
90 #include <linux/kernfs.h>
91 #include <linux/stringhash.h>	/* for hashlen_string() */
92 #include <uapi/linux/mount.h>
93 #include <linux/fsnotify.h>
94 #include <linux/fanotify.h>
95 #include <linux/io_uring/cmd.h>
96 #include <uapi/linux/lsm.h>
97 
98 #include "avc.h"
99 #include "objsec.h"
100 #include "netif.h"
101 #include "netnode.h"
102 #include "netport.h"
103 #include "ibpkey.h"
104 #include "xfrm.h"
105 #include "netlabel.h"
106 #include "audit.h"
107 #include "avc_ss.h"
108 
109 #define SELINUX_INODE_INIT_XATTRS 1
110 
111 struct selinux_state selinux_state;
112 
113 /* SECMARK reference count */
114 static atomic_t selinux_secmark_refcount = ATOMIC_INIT(0);
115 
116 #ifdef CONFIG_SECURITY_SELINUX_DEVELOP
117 static int selinux_enforcing_boot __initdata;
118 
enforcing_setup(char * str)119 static int __init enforcing_setup(char *str)
120 {
121 	unsigned long enforcing;
122 	if (!kstrtoul(str, 0, &enforcing))
123 		selinux_enforcing_boot = enforcing ? 1 : 0;
124 	return 1;
125 }
126 __setup("enforcing=", enforcing_setup);
127 #else
128 #define selinux_enforcing_boot 1
129 #endif
130 
131 int selinux_enabled_boot __initdata = 1;
132 #ifdef CONFIG_SECURITY_SELINUX_BOOTPARAM
selinux_enabled_setup(char * str)133 static int __init selinux_enabled_setup(char *str)
134 {
135 	unsigned long enabled;
136 	if (!kstrtoul(str, 0, &enabled))
137 		selinux_enabled_boot = enabled ? 1 : 0;
138 	return 1;
139 }
140 __setup("selinux=", selinux_enabled_setup);
141 #endif
142 
checkreqprot_setup(char * str)143 static int __init checkreqprot_setup(char *str)
144 {
145 	unsigned long checkreqprot;
146 
147 	if (!kstrtoul(str, 0, &checkreqprot)) {
148 		if (checkreqprot)
149 			pr_err("SELinux: checkreqprot set to 1 via kernel parameter.  This is no longer supported.\n");
150 	}
151 	return 1;
152 }
153 __setup("checkreqprot=", checkreqprot_setup);
154 
155 /**
156  * selinux_secmark_enabled - Check to see if SECMARK is currently enabled
157  *
158  * Description:
159  * This function checks the SECMARK reference counter to see if any SECMARK
160  * targets are currently configured, if the reference counter is greater than
161  * zero SECMARK is considered to be enabled.  Returns true (1) if SECMARK is
162  * enabled, false (0) if SECMARK is disabled.  If the always_check_network
163  * policy capability is enabled, SECMARK is always considered enabled.
164  *
165  */
selinux_secmark_enabled(void)166 static int selinux_secmark_enabled(void)
167 {
168 	return (selinux_policycap_alwaysnetwork() ||
169 		atomic_read(&selinux_secmark_refcount));
170 }
171 
172 /**
173  * selinux_peerlbl_enabled - Check to see if peer labeling is currently enabled
174  *
175  * Description:
176  * This function checks if NetLabel or labeled IPSEC is enabled.  Returns true
177  * (1) if any are enabled or false (0) if neither are enabled.  If the
178  * always_check_network policy capability is enabled, peer labeling
179  * is always considered enabled.
180  *
181  */
selinux_peerlbl_enabled(void)182 static int selinux_peerlbl_enabled(void)
183 {
184 	return (selinux_policycap_alwaysnetwork() ||
185 		netlbl_enabled() || selinux_xfrm_enabled());
186 }
187 
selinux_netcache_avc_callback(u32 event)188 static int selinux_netcache_avc_callback(u32 event)
189 {
190 	if (event == AVC_CALLBACK_RESET) {
191 		sel_netif_flush();
192 		sel_netnode_flush();
193 		sel_netport_flush();
194 		synchronize_net();
195 	}
196 	return 0;
197 }
198 
selinux_lsm_notifier_avc_callback(u32 event)199 static int selinux_lsm_notifier_avc_callback(u32 event)
200 {
201 	if (event == AVC_CALLBACK_RESET) {
202 		sel_ib_pkey_flush();
203 		call_blocking_lsm_notifier(LSM_POLICY_CHANGE, NULL);
204 	}
205 
206 	return 0;
207 }
208 
209 /*
210  * initialise the security for the init task
211  */
cred_init_security(void)212 static void cred_init_security(void)
213 {
214 	struct task_security_struct *tsec;
215 
216 	tsec = selinux_cred(unrcu_pointer(current->real_cred));
217 	tsec->osid = tsec->sid = SECINITSID_KERNEL;
218 }
219 
220 /*
221  * get the security ID of a set of credentials
222  */
cred_sid(const struct cred * cred)223 static inline u32 cred_sid(const struct cred *cred)
224 {
225 	const struct task_security_struct *tsec;
226 
227 	tsec = selinux_cred(cred);
228 	return tsec->sid;
229 }
230 
__ad_net_init(struct common_audit_data * ad,struct lsm_network_audit * net,int ifindex,struct sock * sk,u16 family)231 static void __ad_net_init(struct common_audit_data *ad,
232 			  struct lsm_network_audit *net,
233 			  int ifindex, struct sock *sk, u16 family)
234 {
235 	ad->type = LSM_AUDIT_DATA_NET;
236 	ad->u.net = net;
237 	net->netif = ifindex;
238 	net->sk = sk;
239 	net->family = family;
240 }
241 
ad_net_init_from_sk(struct common_audit_data * ad,struct lsm_network_audit * net,struct sock * sk)242 static void ad_net_init_from_sk(struct common_audit_data *ad,
243 				struct lsm_network_audit *net,
244 				struct sock *sk)
245 {
246 	__ad_net_init(ad, net, 0, sk, 0);
247 }
248 
ad_net_init_from_iif(struct common_audit_data * ad,struct lsm_network_audit * net,int ifindex,u16 family)249 static void ad_net_init_from_iif(struct common_audit_data *ad,
250 				 struct lsm_network_audit *net,
251 				 int ifindex, u16 family)
252 {
253 	__ad_net_init(ad, net, ifindex, NULL, family);
254 }
255 
256 /*
257  * get the objective security ID of a task
258  */
task_sid_obj(const struct task_struct * task)259 static inline u32 task_sid_obj(const struct task_struct *task)
260 {
261 	u32 sid;
262 
263 	rcu_read_lock();
264 	sid = cred_sid(__task_cred(task));
265 	rcu_read_unlock();
266 	return sid;
267 }
268 
269 static int inode_doinit_with_dentry(struct inode *inode, struct dentry *opt_dentry);
270 
271 /*
272  * Try reloading inode security labels that have been marked as invalid.  The
273  * @may_sleep parameter indicates when sleeping and thus reloading labels is
274  * allowed; when set to false, returns -ECHILD when the label is
275  * invalid.  The @dentry parameter should be set to a dentry of the inode.
276  */
__inode_security_revalidate(struct inode * inode,struct dentry * dentry,bool may_sleep)277 static int __inode_security_revalidate(struct inode *inode,
278 				       struct dentry *dentry,
279 				       bool may_sleep)
280 {
281 	struct inode_security_struct *isec = selinux_inode(inode);
282 
283 	might_sleep_if(may_sleep);
284 
285 	/*
286 	 * The check of isec->initialized below is racy but
287 	 * inode_doinit_with_dentry() will recheck with
288 	 * isec->lock held.
289 	 */
290 	if (selinux_initialized() &&
291 	    data_race(isec->initialized != LABEL_INITIALIZED)) {
292 		if (!may_sleep)
293 			return -ECHILD;
294 
295 		/*
296 		 * Try reloading the inode security label.  This will fail if
297 		 * @opt_dentry is NULL and no dentry for this inode can be
298 		 * found; in that case, continue using the old label.
299 		 */
300 		inode_doinit_with_dentry(inode, dentry);
301 	}
302 	return 0;
303 }
304 
inode_security_novalidate(struct inode * inode)305 static struct inode_security_struct *inode_security_novalidate(struct inode *inode)
306 {
307 	return selinux_inode(inode);
308 }
309 
inode_security_rcu(struct inode * inode,bool rcu)310 static struct inode_security_struct *inode_security_rcu(struct inode *inode, bool rcu)
311 {
312 	int error;
313 
314 	error = __inode_security_revalidate(inode, NULL, !rcu);
315 	if (error)
316 		return ERR_PTR(error);
317 	return selinux_inode(inode);
318 }
319 
320 /*
321  * Get the security label of an inode.
322  */
inode_security(struct inode * inode)323 static struct inode_security_struct *inode_security(struct inode *inode)
324 {
325 	__inode_security_revalidate(inode, NULL, true);
326 	return selinux_inode(inode);
327 }
328 
backing_inode_security_novalidate(struct dentry * dentry)329 static struct inode_security_struct *backing_inode_security_novalidate(struct dentry *dentry)
330 {
331 	struct inode *inode = d_backing_inode(dentry);
332 
333 	return selinux_inode(inode);
334 }
335 
336 /*
337  * Get the security label of a dentry's backing inode.
338  */
backing_inode_security(struct dentry * dentry)339 static struct inode_security_struct *backing_inode_security(struct dentry *dentry)
340 {
341 	struct inode *inode = d_backing_inode(dentry);
342 
343 	__inode_security_revalidate(inode, dentry, true);
344 	return selinux_inode(inode);
345 }
346 
inode_free_security(struct inode * inode)347 static void inode_free_security(struct inode *inode)
348 {
349 	struct inode_security_struct *isec = selinux_inode(inode);
350 	struct superblock_security_struct *sbsec;
351 
352 	if (!isec)
353 		return;
354 	sbsec = selinux_superblock(inode->i_sb);
355 	/*
356 	 * As not all inode security structures are in a list, we check for
357 	 * empty list outside of the lock to make sure that we won't waste
358 	 * time taking a lock doing nothing.
359 	 *
360 	 * The list_del_init() function can be safely called more than once.
361 	 * It should not be possible for this function to be called with
362 	 * concurrent list_add(), but for better safety against future changes
363 	 * in the code, we use list_empty_careful() here.
364 	 */
365 	if (!list_empty_careful(&isec->list)) {
366 		spin_lock(&sbsec->isec_lock);
367 		list_del_init(&isec->list);
368 		spin_unlock(&sbsec->isec_lock);
369 	}
370 }
371 
372 struct selinux_mnt_opts {
373 	u32 fscontext_sid;
374 	u32 context_sid;
375 	u32 rootcontext_sid;
376 	u32 defcontext_sid;
377 };
378 
selinux_free_mnt_opts(void * mnt_opts)379 static void selinux_free_mnt_opts(void *mnt_opts)
380 {
381 	kfree(mnt_opts);
382 }
383 
384 enum {
385 	Opt_error = -1,
386 	Opt_context = 0,
387 	Opt_defcontext = 1,
388 	Opt_fscontext = 2,
389 	Opt_rootcontext = 3,
390 	Opt_seclabel = 4,
391 };
392 
393 #define A(s, has_arg) {#s, sizeof(#s) - 1, Opt_##s, has_arg}
394 static const struct {
395 	const char *name;
396 	int len;
397 	int opt;
398 	bool has_arg;
399 } tokens[] = {
400 	A(context, true),
401 	A(fscontext, true),
402 	A(defcontext, true),
403 	A(rootcontext, true),
404 	A(seclabel, false),
405 };
406 #undef A
407 
match_opt_prefix(char * s,int l,char ** arg)408 static int match_opt_prefix(char *s, int l, char **arg)
409 {
410 	unsigned int i;
411 
412 	for (i = 0; i < ARRAY_SIZE(tokens); i++) {
413 		size_t len = tokens[i].len;
414 		if (len > l || memcmp(s, tokens[i].name, len))
415 			continue;
416 		if (tokens[i].has_arg) {
417 			if (len == l || s[len] != '=')
418 				continue;
419 			*arg = s + len + 1;
420 		} else if (len != l)
421 			continue;
422 		return tokens[i].opt;
423 	}
424 	return Opt_error;
425 }
426 
427 #define SEL_MOUNT_FAIL_MSG "SELinux:  duplicate or incompatible mount options\n"
428 
may_context_mount_sb_relabel(u32 sid,struct superblock_security_struct * sbsec,const struct cred * cred)429 static int may_context_mount_sb_relabel(u32 sid,
430 			struct superblock_security_struct *sbsec,
431 			const struct cred *cred)
432 {
433 	const struct task_security_struct *tsec = selinux_cred(cred);
434 	int rc;
435 
436 	rc = avc_has_perm(tsec->sid, sbsec->sid, SECCLASS_FILESYSTEM,
437 			  FILESYSTEM__RELABELFROM, NULL);
438 	if (rc)
439 		return rc;
440 
441 	rc = avc_has_perm(tsec->sid, sid, SECCLASS_FILESYSTEM,
442 			  FILESYSTEM__RELABELTO, NULL);
443 	return rc;
444 }
445 
may_context_mount_inode_relabel(u32 sid,struct superblock_security_struct * sbsec,const struct cred * cred)446 static int may_context_mount_inode_relabel(u32 sid,
447 			struct superblock_security_struct *sbsec,
448 			const struct cred *cred)
449 {
450 	const struct task_security_struct *tsec = selinux_cred(cred);
451 	int rc;
452 	rc = avc_has_perm(tsec->sid, sbsec->sid, SECCLASS_FILESYSTEM,
453 			  FILESYSTEM__RELABELFROM, NULL);
454 	if (rc)
455 		return rc;
456 
457 	rc = avc_has_perm(sid, sbsec->sid, SECCLASS_FILESYSTEM,
458 			  FILESYSTEM__ASSOCIATE, NULL);
459 	return rc;
460 }
461 
selinux_is_genfs_special_handling(struct super_block * sb)462 static int selinux_is_genfs_special_handling(struct super_block *sb)
463 {
464 	/* Special handling. Genfs but also in-core setxattr handler */
465 	return	!strcmp(sb->s_type->name, "sysfs") ||
466 		!strcmp(sb->s_type->name, "pstore") ||
467 		!strcmp(sb->s_type->name, "debugfs") ||
468 		!strcmp(sb->s_type->name, "tracefs") ||
469 		!strcmp(sb->s_type->name, "rootfs") ||
470 		(selinux_policycap_cgroupseclabel() &&
471 		 (!strcmp(sb->s_type->name, "cgroup") ||
472 		  !strcmp(sb->s_type->name, "cgroup2")));
473 }
474 
selinux_is_sblabel_mnt(struct super_block * sb)475 static int selinux_is_sblabel_mnt(struct super_block *sb)
476 {
477 	struct superblock_security_struct *sbsec = selinux_superblock(sb);
478 
479 	/*
480 	 * IMPORTANT: Double-check logic in this function when adding a new
481 	 * SECURITY_FS_USE_* definition!
482 	 */
483 	BUILD_BUG_ON(SECURITY_FS_USE_MAX != 7);
484 
485 	switch (sbsec->behavior) {
486 	case SECURITY_FS_USE_XATTR:
487 	case SECURITY_FS_USE_TRANS:
488 	case SECURITY_FS_USE_TASK:
489 	case SECURITY_FS_USE_NATIVE:
490 		return 1;
491 
492 	case SECURITY_FS_USE_GENFS:
493 		return selinux_is_genfs_special_handling(sb);
494 
495 	/* Never allow relabeling on context mounts */
496 	case SECURITY_FS_USE_MNTPOINT:
497 	case SECURITY_FS_USE_NONE:
498 	default:
499 		return 0;
500 	}
501 }
502 
sb_check_xattr_support(struct super_block * sb)503 static int sb_check_xattr_support(struct super_block *sb)
504 {
505 	struct superblock_security_struct *sbsec = selinux_superblock(sb);
506 	struct dentry *root = sb->s_root;
507 	struct inode *root_inode = d_backing_inode(root);
508 	u32 sid;
509 	int rc;
510 
511 	/*
512 	 * Make sure that the xattr handler exists and that no
513 	 * error other than -ENODATA is returned by getxattr on
514 	 * the root directory.  -ENODATA is ok, as this may be
515 	 * the first boot of the SELinux kernel before we have
516 	 * assigned xattr values to the filesystem.
517 	 */
518 	if (!(root_inode->i_opflags & IOP_XATTR)) {
519 		pr_warn("SELinux: (dev %s, type %s) has no xattr support\n",
520 			sb->s_id, sb->s_type->name);
521 		goto fallback;
522 	}
523 
524 	rc = __vfs_getxattr(root, root_inode, XATTR_NAME_SELINUX, NULL, 0);
525 	if (rc < 0 && rc != -ENODATA) {
526 		if (rc == -EOPNOTSUPP) {
527 			pr_warn("SELinux: (dev %s, type %s) has no security xattr handler\n",
528 				sb->s_id, sb->s_type->name);
529 			goto fallback;
530 		} else {
531 			pr_warn("SELinux: (dev %s, type %s) getxattr errno %d\n",
532 				sb->s_id, sb->s_type->name, -rc);
533 			return rc;
534 		}
535 	}
536 	return 0;
537 
538 fallback:
539 	/* No xattr support - try to fallback to genfs if possible. */
540 	rc = security_genfs_sid(sb->s_type->name, "/",
541 				SECCLASS_DIR, &sid);
542 	if (rc)
543 		return -EOPNOTSUPP;
544 
545 	pr_warn("SELinux: (dev %s, type %s) falling back to genfs\n",
546 		sb->s_id, sb->s_type->name);
547 	sbsec->behavior = SECURITY_FS_USE_GENFS;
548 	sbsec->sid = sid;
549 	return 0;
550 }
551 
sb_finish_set_opts(struct super_block * sb)552 static int sb_finish_set_opts(struct super_block *sb)
553 {
554 	struct superblock_security_struct *sbsec = selinux_superblock(sb);
555 	struct dentry *root = sb->s_root;
556 	struct inode *root_inode = d_backing_inode(root);
557 	int rc = 0;
558 
559 	if (sbsec->behavior == SECURITY_FS_USE_XATTR) {
560 		rc = sb_check_xattr_support(sb);
561 		if (rc)
562 			return rc;
563 	}
564 
565 	sbsec->flags |= SE_SBINITIALIZED;
566 
567 	/*
568 	 * Explicitly set or clear SBLABEL_MNT.  It's not sufficient to simply
569 	 * leave the flag untouched because sb_clone_mnt_opts might be handing
570 	 * us a superblock that needs the flag to be cleared.
571 	 */
572 	if (selinux_is_sblabel_mnt(sb))
573 		sbsec->flags |= SBLABEL_MNT;
574 	else
575 		sbsec->flags &= ~SBLABEL_MNT;
576 
577 	/* Initialize the root inode. */
578 	rc = inode_doinit_with_dentry(root_inode, root);
579 
580 	/* Initialize any other inodes associated with the superblock, e.g.
581 	   inodes created prior to initial policy load or inodes created
582 	   during get_sb by a pseudo filesystem that directly
583 	   populates itself. */
584 	spin_lock(&sbsec->isec_lock);
585 	while (!list_empty(&sbsec->isec_head)) {
586 		struct inode_security_struct *isec =
587 				list_first_entry(&sbsec->isec_head,
588 					   struct inode_security_struct, list);
589 		struct inode *inode = isec->inode;
590 		list_del_init(&isec->list);
591 		spin_unlock(&sbsec->isec_lock);
592 		inode = igrab(inode);
593 		if (inode) {
594 			if (!IS_PRIVATE(inode))
595 				inode_doinit_with_dentry(inode, NULL);
596 			iput(inode);
597 		}
598 		spin_lock(&sbsec->isec_lock);
599 	}
600 	spin_unlock(&sbsec->isec_lock);
601 	return rc;
602 }
603 
bad_option(struct superblock_security_struct * sbsec,char flag,u32 old_sid,u32 new_sid)604 static int bad_option(struct superblock_security_struct *sbsec, char flag,
605 		      u32 old_sid, u32 new_sid)
606 {
607 	char mnt_flags = sbsec->flags & SE_MNTMASK;
608 
609 	/* check if the old mount command had the same options */
610 	if (sbsec->flags & SE_SBINITIALIZED)
611 		if (!(sbsec->flags & flag) ||
612 		    (old_sid != new_sid))
613 			return 1;
614 
615 	/* check if we were passed the same options twice,
616 	 * aka someone passed context=a,context=b
617 	 */
618 	if (!(sbsec->flags & SE_SBINITIALIZED))
619 		if (mnt_flags & flag)
620 			return 1;
621 	return 0;
622 }
623 
624 /*
625  * Allow filesystems with binary mount data to explicitly set mount point
626  * labeling information.
627  */
selinux_set_mnt_opts(struct super_block * sb,void * mnt_opts,unsigned long kern_flags,unsigned long * set_kern_flags)628 static int selinux_set_mnt_opts(struct super_block *sb,
629 				void *mnt_opts,
630 				unsigned long kern_flags,
631 				unsigned long *set_kern_flags)
632 {
633 	const struct cred *cred = current_cred();
634 	struct superblock_security_struct *sbsec = selinux_superblock(sb);
635 	struct dentry *root = sb->s_root;
636 	struct selinux_mnt_opts *opts = mnt_opts;
637 	struct inode_security_struct *root_isec;
638 	u32 fscontext_sid = 0, context_sid = 0, rootcontext_sid = 0;
639 	u32 defcontext_sid = 0;
640 	int rc = 0;
641 
642 	/*
643 	 * Specifying internal flags without providing a place to
644 	 * place the results is not allowed
645 	 */
646 	if (kern_flags && !set_kern_flags)
647 		return -EINVAL;
648 
649 	mutex_lock(&sbsec->lock);
650 
651 	if (!selinux_initialized()) {
652 		if (!opts) {
653 			/* Defer initialization until selinux_complete_init,
654 			   after the initial policy is loaded and the security
655 			   server is ready to handle calls. */
656 			if (kern_flags & SECURITY_LSM_NATIVE_LABELS) {
657 				sbsec->flags |= SE_SBNATIVE;
658 				*set_kern_flags |= SECURITY_LSM_NATIVE_LABELS;
659 			}
660 			goto out;
661 		}
662 		rc = -EINVAL;
663 		pr_warn("SELinux: Unable to set superblock options "
664 			"before the security server is initialized\n");
665 		goto out;
666 	}
667 
668 	/*
669 	 * Binary mount data FS will come through this function twice.  Once
670 	 * from an explicit call and once from the generic calls from the vfs.
671 	 * Since the generic VFS calls will not contain any security mount data
672 	 * we need to skip the double mount verification.
673 	 *
674 	 * This does open a hole in which we will not notice if the first
675 	 * mount using this sb set explicit options and a second mount using
676 	 * this sb does not set any security options.  (The first options
677 	 * will be used for both mounts)
678 	 */
679 	if ((sbsec->flags & SE_SBINITIALIZED) && (sb->s_type->fs_flags & FS_BINARY_MOUNTDATA)
680 	    && !opts)
681 		goto out;
682 
683 	root_isec = backing_inode_security_novalidate(root);
684 
685 	/*
686 	 * parse the mount options, check if they are valid sids.
687 	 * also check if someone is trying to mount the same sb more
688 	 * than once with different security options.
689 	 */
690 	if (opts) {
691 		if (opts->fscontext_sid) {
692 			fscontext_sid = opts->fscontext_sid;
693 			if (bad_option(sbsec, FSCONTEXT_MNT, sbsec->sid,
694 					fscontext_sid))
695 				goto out_double_mount;
696 			sbsec->flags |= FSCONTEXT_MNT;
697 		}
698 		if (opts->context_sid) {
699 			context_sid = opts->context_sid;
700 			if (bad_option(sbsec, CONTEXT_MNT, sbsec->mntpoint_sid,
701 					context_sid))
702 				goto out_double_mount;
703 			sbsec->flags |= CONTEXT_MNT;
704 		}
705 		if (opts->rootcontext_sid) {
706 			rootcontext_sid = opts->rootcontext_sid;
707 			if (bad_option(sbsec, ROOTCONTEXT_MNT, root_isec->sid,
708 					rootcontext_sid))
709 				goto out_double_mount;
710 			sbsec->flags |= ROOTCONTEXT_MNT;
711 		}
712 		if (opts->defcontext_sid) {
713 			defcontext_sid = opts->defcontext_sid;
714 			if (bad_option(sbsec, DEFCONTEXT_MNT, sbsec->def_sid,
715 					defcontext_sid))
716 				goto out_double_mount;
717 			sbsec->flags |= DEFCONTEXT_MNT;
718 		}
719 	}
720 
721 	if (sbsec->flags & SE_SBINITIALIZED) {
722 		/* previously mounted with options, but not on this attempt? */
723 		if ((sbsec->flags & SE_MNTMASK) && !opts)
724 			goto out_double_mount;
725 		rc = 0;
726 		goto out;
727 	}
728 
729 	if (strcmp(sb->s_type->name, "proc") == 0)
730 		sbsec->flags |= SE_SBPROC | SE_SBGENFS;
731 
732 	if (!strcmp(sb->s_type->name, "debugfs") ||
733 	    !strcmp(sb->s_type->name, "tracefs") ||
734 	    !strcmp(sb->s_type->name, "binder") ||
735 	    !strcmp(sb->s_type->name, "bpf") ||
736 	    !strcmp(sb->s_type->name, "pstore") ||
737 	    !strcmp(sb->s_type->name, "securityfs"))
738 		sbsec->flags |= SE_SBGENFS;
739 
740 	if (!strcmp(sb->s_type->name, "sysfs") ||
741 	    !strcmp(sb->s_type->name, "cgroup") ||
742 	    !strcmp(sb->s_type->name, "cgroup2"))
743 		sbsec->flags |= SE_SBGENFS | SE_SBGENFS_XATTR;
744 
745 	if (!sbsec->behavior) {
746 		/*
747 		 * Determine the labeling behavior to use for this
748 		 * filesystem type.
749 		 */
750 		rc = security_fs_use(sb);
751 		if (rc) {
752 			pr_warn("%s: security_fs_use(%s) returned %d\n",
753 					__func__, sb->s_type->name, rc);
754 			goto out;
755 		}
756 	}
757 
758 	/*
759 	 * If this is a user namespace mount and the filesystem type is not
760 	 * explicitly whitelisted, then no contexts are allowed on the command
761 	 * line and security labels must be ignored.
762 	 */
763 	if (sb->s_user_ns != &init_user_ns &&
764 	    strcmp(sb->s_type->name, "tmpfs") &&
765 	    strcmp(sb->s_type->name, "ramfs") &&
766 	    strcmp(sb->s_type->name, "devpts") &&
767 	    strcmp(sb->s_type->name, "overlay")) {
768 		if (context_sid || fscontext_sid || rootcontext_sid ||
769 		    defcontext_sid) {
770 			rc = -EACCES;
771 			goto out;
772 		}
773 		if (sbsec->behavior == SECURITY_FS_USE_XATTR) {
774 			sbsec->behavior = SECURITY_FS_USE_MNTPOINT;
775 			rc = security_transition_sid(current_sid(),
776 						     current_sid(),
777 						     SECCLASS_FILE, NULL,
778 						     &sbsec->mntpoint_sid);
779 			if (rc)
780 				goto out;
781 		}
782 		goto out_set_opts;
783 	}
784 
785 	/* sets the context of the superblock for the fs being mounted. */
786 	if (fscontext_sid) {
787 		rc = may_context_mount_sb_relabel(fscontext_sid, sbsec, cred);
788 		if (rc)
789 			goto out;
790 
791 		sbsec->sid = fscontext_sid;
792 	}
793 
794 	/*
795 	 * Switch to using mount point labeling behavior.
796 	 * sets the label used on all file below the mountpoint, and will set
797 	 * the superblock context if not already set.
798 	 */
799 	if (sbsec->flags & SE_SBNATIVE) {
800 		/*
801 		 * This means we are initializing a superblock that has been
802 		 * mounted before the SELinux was initialized and the
803 		 * filesystem requested native labeling. We had already
804 		 * returned SECURITY_LSM_NATIVE_LABELS in *set_kern_flags
805 		 * in the original mount attempt, so now we just need to set
806 		 * the SECURITY_FS_USE_NATIVE behavior.
807 		 */
808 		sbsec->behavior = SECURITY_FS_USE_NATIVE;
809 	} else if (kern_flags & SECURITY_LSM_NATIVE_LABELS && !context_sid) {
810 		sbsec->behavior = SECURITY_FS_USE_NATIVE;
811 		*set_kern_flags |= SECURITY_LSM_NATIVE_LABELS;
812 	}
813 
814 	if (context_sid) {
815 		if (!fscontext_sid) {
816 			rc = may_context_mount_sb_relabel(context_sid, sbsec,
817 							  cred);
818 			if (rc)
819 				goto out;
820 			sbsec->sid = context_sid;
821 		} else {
822 			rc = may_context_mount_inode_relabel(context_sid, sbsec,
823 							     cred);
824 			if (rc)
825 				goto out;
826 		}
827 		if (!rootcontext_sid)
828 			rootcontext_sid = context_sid;
829 
830 		sbsec->mntpoint_sid = context_sid;
831 		sbsec->behavior = SECURITY_FS_USE_MNTPOINT;
832 	}
833 
834 	if (rootcontext_sid) {
835 		rc = may_context_mount_inode_relabel(rootcontext_sid, sbsec,
836 						     cred);
837 		if (rc)
838 			goto out;
839 
840 		root_isec->sid = rootcontext_sid;
841 		root_isec->initialized = LABEL_INITIALIZED;
842 	}
843 
844 	if (defcontext_sid) {
845 		if (sbsec->behavior != SECURITY_FS_USE_XATTR &&
846 			sbsec->behavior != SECURITY_FS_USE_NATIVE) {
847 			rc = -EINVAL;
848 			pr_warn("SELinux: defcontext option is "
849 			       "invalid for this filesystem type\n");
850 			goto out;
851 		}
852 
853 		if (defcontext_sid != sbsec->def_sid) {
854 			rc = may_context_mount_inode_relabel(defcontext_sid,
855 							     sbsec, cred);
856 			if (rc)
857 				goto out;
858 		}
859 
860 		sbsec->def_sid = defcontext_sid;
861 	}
862 
863 out_set_opts:
864 	rc = sb_finish_set_opts(sb);
865 out:
866 	mutex_unlock(&sbsec->lock);
867 	return rc;
868 out_double_mount:
869 	rc = -EINVAL;
870 	pr_warn("SELinux: mount invalid.  Same superblock, different "
871 	       "security settings for (dev %s, type %s)\n", sb->s_id,
872 	       sb->s_type->name);
873 	goto out;
874 }
875 
selinux_cmp_sb_context(const struct super_block * oldsb,const struct super_block * newsb)876 static int selinux_cmp_sb_context(const struct super_block *oldsb,
877 				    const struct super_block *newsb)
878 {
879 	struct superblock_security_struct *old = selinux_superblock(oldsb);
880 	struct superblock_security_struct *new = selinux_superblock(newsb);
881 	char oldflags = old->flags & SE_MNTMASK;
882 	char newflags = new->flags & SE_MNTMASK;
883 
884 	if (oldflags != newflags)
885 		goto mismatch;
886 	if ((oldflags & FSCONTEXT_MNT) && old->sid != new->sid)
887 		goto mismatch;
888 	if ((oldflags & CONTEXT_MNT) && old->mntpoint_sid != new->mntpoint_sid)
889 		goto mismatch;
890 	if ((oldflags & DEFCONTEXT_MNT) && old->def_sid != new->def_sid)
891 		goto mismatch;
892 	if (oldflags & ROOTCONTEXT_MNT) {
893 		struct inode_security_struct *oldroot = backing_inode_security(oldsb->s_root);
894 		struct inode_security_struct *newroot = backing_inode_security(newsb->s_root);
895 		if (oldroot->sid != newroot->sid)
896 			goto mismatch;
897 	}
898 	return 0;
899 mismatch:
900 	pr_warn("SELinux: mount invalid.  Same superblock, "
901 			    "different security settings for (dev %s, "
902 			    "type %s)\n", newsb->s_id, newsb->s_type->name);
903 	return -EBUSY;
904 }
905 
selinux_sb_clone_mnt_opts(const struct super_block * oldsb,struct super_block * newsb,unsigned long kern_flags,unsigned long * set_kern_flags)906 static int selinux_sb_clone_mnt_opts(const struct super_block *oldsb,
907 					struct super_block *newsb,
908 					unsigned long kern_flags,
909 					unsigned long *set_kern_flags)
910 {
911 	int rc = 0;
912 	const struct superblock_security_struct *oldsbsec =
913 						selinux_superblock(oldsb);
914 	struct superblock_security_struct *newsbsec = selinux_superblock(newsb);
915 
916 	int set_fscontext =	(oldsbsec->flags & FSCONTEXT_MNT);
917 	int set_context =	(oldsbsec->flags & CONTEXT_MNT);
918 	int set_rootcontext =	(oldsbsec->flags & ROOTCONTEXT_MNT);
919 
920 	/*
921 	 * Specifying internal flags without providing a place to
922 	 * place the results is not allowed.
923 	 */
924 	if (kern_flags && !set_kern_flags)
925 		return -EINVAL;
926 
927 	mutex_lock(&newsbsec->lock);
928 
929 	/*
930 	 * if the parent was able to be mounted it clearly had no special lsm
931 	 * mount options.  thus we can safely deal with this superblock later
932 	 */
933 	if (!selinux_initialized()) {
934 		if (kern_flags & SECURITY_LSM_NATIVE_LABELS) {
935 			newsbsec->flags |= SE_SBNATIVE;
936 			*set_kern_flags |= SECURITY_LSM_NATIVE_LABELS;
937 		}
938 		goto out;
939 	}
940 
941 	/* how can we clone if the old one wasn't set up?? */
942 	BUG_ON(!(oldsbsec->flags & SE_SBINITIALIZED));
943 
944 	/* if fs is reusing a sb, make sure that the contexts match */
945 	if (newsbsec->flags & SE_SBINITIALIZED) {
946 		mutex_unlock(&newsbsec->lock);
947 		if ((kern_flags & SECURITY_LSM_NATIVE_LABELS) && !set_context)
948 			*set_kern_flags |= SECURITY_LSM_NATIVE_LABELS;
949 		return selinux_cmp_sb_context(oldsb, newsb);
950 	}
951 
952 	newsbsec->flags = oldsbsec->flags;
953 
954 	newsbsec->sid = oldsbsec->sid;
955 	newsbsec->def_sid = oldsbsec->def_sid;
956 	newsbsec->behavior = oldsbsec->behavior;
957 
958 	if (newsbsec->behavior == SECURITY_FS_USE_NATIVE &&
959 		!(kern_flags & SECURITY_LSM_NATIVE_LABELS) && !set_context) {
960 		rc = security_fs_use(newsb);
961 		if (rc)
962 			goto out;
963 	}
964 
965 	if (kern_flags & SECURITY_LSM_NATIVE_LABELS && !set_context) {
966 		newsbsec->behavior = SECURITY_FS_USE_NATIVE;
967 		*set_kern_flags |= SECURITY_LSM_NATIVE_LABELS;
968 	}
969 
970 	if (set_context) {
971 		u32 sid = oldsbsec->mntpoint_sid;
972 
973 		if (!set_fscontext)
974 			newsbsec->sid = sid;
975 		if (!set_rootcontext) {
976 			struct inode_security_struct *newisec = backing_inode_security(newsb->s_root);
977 			newisec->sid = sid;
978 		}
979 		newsbsec->mntpoint_sid = sid;
980 	}
981 	if (set_rootcontext) {
982 		const struct inode_security_struct *oldisec = backing_inode_security(oldsb->s_root);
983 		struct inode_security_struct *newisec = backing_inode_security(newsb->s_root);
984 
985 		newisec->sid = oldisec->sid;
986 	}
987 
988 	sb_finish_set_opts(newsb);
989 out:
990 	mutex_unlock(&newsbsec->lock);
991 	return rc;
992 }
993 
994 /*
995  * NOTE: the caller is responsible for freeing the memory even if on error.
996  */
selinux_add_opt(int token,const char * s,void ** mnt_opts)997 static int selinux_add_opt(int token, const char *s, void **mnt_opts)
998 {
999 	struct selinux_mnt_opts *opts = *mnt_opts;
1000 	u32 *dst_sid;
1001 	int rc;
1002 
1003 	if (token == Opt_seclabel)
1004 		/* eaten and completely ignored */
1005 		return 0;
1006 	if (!s)
1007 		return -EINVAL;
1008 
1009 	if (!selinux_initialized()) {
1010 		pr_warn("SELinux: Unable to set superblock options before the security server is initialized\n");
1011 		return -EINVAL;
1012 	}
1013 
1014 	if (!opts) {
1015 		opts = kzalloc(sizeof(*opts), GFP_KERNEL);
1016 		if (!opts)
1017 			return -ENOMEM;
1018 		*mnt_opts = opts;
1019 	}
1020 
1021 	switch (token) {
1022 	case Opt_context:
1023 		if (opts->context_sid || opts->defcontext_sid)
1024 			goto err;
1025 		dst_sid = &opts->context_sid;
1026 		break;
1027 	case Opt_fscontext:
1028 		if (opts->fscontext_sid)
1029 			goto err;
1030 		dst_sid = &opts->fscontext_sid;
1031 		break;
1032 	case Opt_rootcontext:
1033 		if (opts->rootcontext_sid)
1034 			goto err;
1035 		dst_sid = &opts->rootcontext_sid;
1036 		break;
1037 	case Opt_defcontext:
1038 		if (opts->context_sid || opts->defcontext_sid)
1039 			goto err;
1040 		dst_sid = &opts->defcontext_sid;
1041 		break;
1042 	default:
1043 		WARN_ON(1);
1044 		return -EINVAL;
1045 	}
1046 	rc = security_context_str_to_sid(s, dst_sid, GFP_KERNEL);
1047 	if (rc)
1048 		pr_warn("SELinux: security_context_str_to_sid (%s) failed with errno=%d\n",
1049 			s, rc);
1050 	return rc;
1051 
1052 err:
1053 	pr_warn(SEL_MOUNT_FAIL_MSG);
1054 	return -EINVAL;
1055 }
1056 
show_sid(struct seq_file * m,u32 sid)1057 static int show_sid(struct seq_file *m, u32 sid)
1058 {
1059 	char *context = NULL;
1060 	u32 len;
1061 	int rc;
1062 
1063 	rc = security_sid_to_context(sid, &context, &len);
1064 	if (!rc) {
1065 		bool has_comma = strchr(context, ',');
1066 
1067 		seq_putc(m, '=');
1068 		if (has_comma)
1069 			seq_putc(m, '\"');
1070 		seq_escape(m, context, "\"\n\\");
1071 		if (has_comma)
1072 			seq_putc(m, '\"');
1073 	}
1074 	kfree(context);
1075 	return rc;
1076 }
1077 
selinux_sb_show_options(struct seq_file * m,struct super_block * sb)1078 static int selinux_sb_show_options(struct seq_file *m, struct super_block *sb)
1079 {
1080 	struct superblock_security_struct *sbsec = selinux_superblock(sb);
1081 	int rc;
1082 
1083 	if (!(sbsec->flags & SE_SBINITIALIZED))
1084 		return 0;
1085 
1086 	if (!selinux_initialized())
1087 		return 0;
1088 
1089 	if (sbsec->flags & FSCONTEXT_MNT) {
1090 		seq_putc(m, ',');
1091 		seq_puts(m, FSCONTEXT_STR);
1092 		rc = show_sid(m, sbsec->sid);
1093 		if (rc)
1094 			return rc;
1095 	}
1096 	if (sbsec->flags & CONTEXT_MNT) {
1097 		seq_putc(m, ',');
1098 		seq_puts(m, CONTEXT_STR);
1099 		rc = show_sid(m, sbsec->mntpoint_sid);
1100 		if (rc)
1101 			return rc;
1102 	}
1103 	if (sbsec->flags & DEFCONTEXT_MNT) {
1104 		seq_putc(m, ',');
1105 		seq_puts(m, DEFCONTEXT_STR);
1106 		rc = show_sid(m, sbsec->def_sid);
1107 		if (rc)
1108 			return rc;
1109 	}
1110 	if (sbsec->flags & ROOTCONTEXT_MNT) {
1111 		struct dentry *root = sb->s_root;
1112 		struct inode_security_struct *isec = backing_inode_security(root);
1113 		seq_putc(m, ',');
1114 		seq_puts(m, ROOTCONTEXT_STR);
1115 		rc = show_sid(m, isec->sid);
1116 		if (rc)
1117 			return rc;
1118 	}
1119 	if (sbsec->flags & SBLABEL_MNT) {
1120 		seq_putc(m, ',');
1121 		seq_puts(m, SECLABEL_STR);
1122 	}
1123 	return 0;
1124 }
1125 
inode_mode_to_security_class(umode_t mode)1126 static inline u16 inode_mode_to_security_class(umode_t mode)
1127 {
1128 	switch (mode & S_IFMT) {
1129 	case S_IFSOCK:
1130 		return SECCLASS_SOCK_FILE;
1131 	case S_IFLNK:
1132 		return SECCLASS_LNK_FILE;
1133 	case S_IFREG:
1134 		return SECCLASS_FILE;
1135 	case S_IFBLK:
1136 		return SECCLASS_BLK_FILE;
1137 	case S_IFDIR:
1138 		return SECCLASS_DIR;
1139 	case S_IFCHR:
1140 		return SECCLASS_CHR_FILE;
1141 	case S_IFIFO:
1142 		return SECCLASS_FIFO_FILE;
1143 
1144 	}
1145 
1146 	return SECCLASS_FILE;
1147 }
1148 
default_protocol_stream(int protocol)1149 static inline int default_protocol_stream(int protocol)
1150 {
1151 	return (protocol == IPPROTO_IP || protocol == IPPROTO_TCP ||
1152 		protocol == IPPROTO_MPTCP);
1153 }
1154 
default_protocol_dgram(int protocol)1155 static inline int default_protocol_dgram(int protocol)
1156 {
1157 	return (protocol == IPPROTO_IP || protocol == IPPROTO_UDP);
1158 }
1159 
socket_type_to_security_class(int family,int type,int protocol)1160 static inline u16 socket_type_to_security_class(int family, int type, int protocol)
1161 {
1162 	bool extsockclass = selinux_policycap_extsockclass();
1163 
1164 	switch (family) {
1165 	case PF_UNIX:
1166 		switch (type) {
1167 		case SOCK_STREAM:
1168 		case SOCK_SEQPACKET:
1169 			return SECCLASS_UNIX_STREAM_SOCKET;
1170 		case SOCK_DGRAM:
1171 		case SOCK_RAW:
1172 			return SECCLASS_UNIX_DGRAM_SOCKET;
1173 		}
1174 		break;
1175 	case PF_INET:
1176 	case PF_INET6:
1177 		switch (type) {
1178 		case SOCK_STREAM:
1179 		case SOCK_SEQPACKET:
1180 			if (default_protocol_stream(protocol))
1181 				return SECCLASS_TCP_SOCKET;
1182 			else if (extsockclass && protocol == IPPROTO_SCTP)
1183 				return SECCLASS_SCTP_SOCKET;
1184 			else
1185 				return SECCLASS_RAWIP_SOCKET;
1186 		case SOCK_DGRAM:
1187 			if (default_protocol_dgram(protocol))
1188 				return SECCLASS_UDP_SOCKET;
1189 			else if (extsockclass && (protocol == IPPROTO_ICMP ||
1190 						  protocol == IPPROTO_ICMPV6))
1191 				return SECCLASS_ICMP_SOCKET;
1192 			else
1193 				return SECCLASS_RAWIP_SOCKET;
1194 		case SOCK_DCCP:
1195 			return SECCLASS_DCCP_SOCKET;
1196 		default:
1197 			return SECCLASS_RAWIP_SOCKET;
1198 		}
1199 		break;
1200 	case PF_NETLINK:
1201 		switch (protocol) {
1202 		case NETLINK_ROUTE:
1203 			return SECCLASS_NETLINK_ROUTE_SOCKET;
1204 		case NETLINK_SOCK_DIAG:
1205 			return SECCLASS_NETLINK_TCPDIAG_SOCKET;
1206 		case NETLINK_NFLOG:
1207 			return SECCLASS_NETLINK_NFLOG_SOCKET;
1208 		case NETLINK_XFRM:
1209 			return SECCLASS_NETLINK_XFRM_SOCKET;
1210 		case NETLINK_SELINUX:
1211 			return SECCLASS_NETLINK_SELINUX_SOCKET;
1212 		case NETLINK_ISCSI:
1213 			return SECCLASS_NETLINK_ISCSI_SOCKET;
1214 		case NETLINK_AUDIT:
1215 			return SECCLASS_NETLINK_AUDIT_SOCKET;
1216 		case NETLINK_FIB_LOOKUP:
1217 			return SECCLASS_NETLINK_FIB_LOOKUP_SOCKET;
1218 		case NETLINK_CONNECTOR:
1219 			return SECCLASS_NETLINK_CONNECTOR_SOCKET;
1220 		case NETLINK_NETFILTER:
1221 			return SECCLASS_NETLINK_NETFILTER_SOCKET;
1222 		case NETLINK_DNRTMSG:
1223 			return SECCLASS_NETLINK_DNRT_SOCKET;
1224 		case NETLINK_KOBJECT_UEVENT:
1225 			return SECCLASS_NETLINK_KOBJECT_UEVENT_SOCKET;
1226 		case NETLINK_GENERIC:
1227 			return SECCLASS_NETLINK_GENERIC_SOCKET;
1228 		case NETLINK_SCSITRANSPORT:
1229 			return SECCLASS_NETLINK_SCSITRANSPORT_SOCKET;
1230 		case NETLINK_RDMA:
1231 			return SECCLASS_NETLINK_RDMA_SOCKET;
1232 		case NETLINK_CRYPTO:
1233 			return SECCLASS_NETLINK_CRYPTO_SOCKET;
1234 		default:
1235 			return SECCLASS_NETLINK_SOCKET;
1236 		}
1237 	case PF_PACKET:
1238 		return SECCLASS_PACKET_SOCKET;
1239 	case PF_KEY:
1240 		return SECCLASS_KEY_SOCKET;
1241 	case PF_APPLETALK:
1242 		return SECCLASS_APPLETALK_SOCKET;
1243 	}
1244 
1245 	if (extsockclass) {
1246 		switch (family) {
1247 		case PF_AX25:
1248 			return SECCLASS_AX25_SOCKET;
1249 		case PF_IPX:
1250 			return SECCLASS_IPX_SOCKET;
1251 		case PF_NETROM:
1252 			return SECCLASS_NETROM_SOCKET;
1253 		case PF_ATMPVC:
1254 			return SECCLASS_ATMPVC_SOCKET;
1255 		case PF_X25:
1256 			return SECCLASS_X25_SOCKET;
1257 		case PF_ROSE:
1258 			return SECCLASS_ROSE_SOCKET;
1259 		case PF_DECnet:
1260 			return SECCLASS_DECNET_SOCKET;
1261 		case PF_ATMSVC:
1262 			return SECCLASS_ATMSVC_SOCKET;
1263 		case PF_RDS:
1264 			return SECCLASS_RDS_SOCKET;
1265 		case PF_IRDA:
1266 			return SECCLASS_IRDA_SOCKET;
1267 		case PF_PPPOX:
1268 			return SECCLASS_PPPOX_SOCKET;
1269 		case PF_LLC:
1270 			return SECCLASS_LLC_SOCKET;
1271 		case PF_CAN:
1272 			return SECCLASS_CAN_SOCKET;
1273 		case PF_TIPC:
1274 			return SECCLASS_TIPC_SOCKET;
1275 		case PF_BLUETOOTH:
1276 			return SECCLASS_BLUETOOTH_SOCKET;
1277 		case PF_IUCV:
1278 			return SECCLASS_IUCV_SOCKET;
1279 		case PF_RXRPC:
1280 			return SECCLASS_RXRPC_SOCKET;
1281 		case PF_ISDN:
1282 			return SECCLASS_ISDN_SOCKET;
1283 		case PF_PHONET:
1284 			return SECCLASS_PHONET_SOCKET;
1285 		case PF_IEEE802154:
1286 			return SECCLASS_IEEE802154_SOCKET;
1287 		case PF_CAIF:
1288 			return SECCLASS_CAIF_SOCKET;
1289 		case PF_ALG:
1290 			return SECCLASS_ALG_SOCKET;
1291 		case PF_NFC:
1292 			return SECCLASS_NFC_SOCKET;
1293 		case PF_VSOCK:
1294 			return SECCLASS_VSOCK_SOCKET;
1295 		case PF_KCM:
1296 			return SECCLASS_KCM_SOCKET;
1297 		case PF_QIPCRTR:
1298 			return SECCLASS_QIPCRTR_SOCKET;
1299 		case PF_SMC:
1300 			return SECCLASS_SMC_SOCKET;
1301 		case PF_XDP:
1302 			return SECCLASS_XDP_SOCKET;
1303 		case PF_MCTP:
1304 			return SECCLASS_MCTP_SOCKET;
1305 #if PF_MAX > 46
1306 #error New address family defined, please update this function.
1307 #endif
1308 		}
1309 	}
1310 
1311 	return SECCLASS_SOCKET;
1312 }
1313 
selinux_genfs_get_sid(struct dentry * dentry,u16 tclass,u16 flags,u32 * sid)1314 static int selinux_genfs_get_sid(struct dentry *dentry,
1315 				 u16 tclass,
1316 				 u16 flags,
1317 				 u32 *sid)
1318 {
1319 	int rc;
1320 	struct super_block *sb = dentry->d_sb;
1321 	char *buffer, *path;
1322 
1323 	buffer = (char *)__get_free_page(GFP_KERNEL);
1324 	if (!buffer)
1325 		return -ENOMEM;
1326 
1327 	path = dentry_path_raw(dentry, buffer, PAGE_SIZE);
1328 	if (IS_ERR(path))
1329 		rc = PTR_ERR(path);
1330 	else {
1331 		if (flags & SE_SBPROC) {
1332 			/* each process gets a /proc/PID/ entry. Strip off the
1333 			 * PID part to get a valid selinux labeling.
1334 			 * e.g. /proc/1/net/rpc/nfs -> /net/rpc/nfs */
1335 			while (path[1] >= '0' && path[1] <= '9') {
1336 				path[1] = '/';
1337 				path++;
1338 			}
1339 		}
1340 		rc = security_genfs_sid(sb->s_type->name,
1341 					path, tclass, sid);
1342 		if (rc == -ENOENT) {
1343 			/* No match in policy, mark as unlabeled. */
1344 			*sid = SECINITSID_UNLABELED;
1345 			rc = 0;
1346 		}
1347 	}
1348 	free_page((unsigned long)buffer);
1349 	return rc;
1350 }
1351 
inode_doinit_use_xattr(struct inode * inode,struct dentry * dentry,u32 def_sid,u32 * sid)1352 static int inode_doinit_use_xattr(struct inode *inode, struct dentry *dentry,
1353 				  u32 def_sid, u32 *sid)
1354 {
1355 #define INITCONTEXTLEN 255
1356 	char *context;
1357 	unsigned int len;
1358 	int rc;
1359 
1360 	len = INITCONTEXTLEN;
1361 	context = kmalloc(len + 1, GFP_NOFS);
1362 	if (!context)
1363 		return -ENOMEM;
1364 
1365 	context[len] = '\0';
1366 	rc = __vfs_getxattr(dentry, inode, XATTR_NAME_SELINUX, context, len);
1367 	if (rc == -ERANGE) {
1368 		kfree(context);
1369 
1370 		/* Need a larger buffer.  Query for the right size. */
1371 		rc = __vfs_getxattr(dentry, inode, XATTR_NAME_SELINUX, NULL, 0);
1372 		if (rc < 0)
1373 			return rc;
1374 
1375 		len = rc;
1376 		context = kmalloc(len + 1, GFP_NOFS);
1377 		if (!context)
1378 			return -ENOMEM;
1379 
1380 		context[len] = '\0';
1381 		rc = __vfs_getxattr(dentry, inode, XATTR_NAME_SELINUX,
1382 				    context, len);
1383 	}
1384 	if (rc < 0) {
1385 		kfree(context);
1386 		if (rc != -ENODATA) {
1387 			pr_warn("SELinux: %s:  getxattr returned %d for dev=%s ino=%ld\n",
1388 				__func__, -rc, inode->i_sb->s_id, inode->i_ino);
1389 			return rc;
1390 		}
1391 		*sid = def_sid;
1392 		return 0;
1393 	}
1394 
1395 	rc = security_context_to_sid_default(context, rc, sid,
1396 					     def_sid, GFP_NOFS);
1397 	if (rc) {
1398 		char *dev = inode->i_sb->s_id;
1399 		unsigned long ino = inode->i_ino;
1400 
1401 		if (rc == -EINVAL) {
1402 			pr_notice_ratelimited("SELinux: inode=%lu on dev=%s was found to have an invalid context=%s.  This indicates you may need to relabel the inode or the filesystem in question.\n",
1403 					      ino, dev, context);
1404 		} else {
1405 			pr_warn("SELinux: %s:  context_to_sid(%s) returned %d for dev=%s ino=%ld\n",
1406 				__func__, context, -rc, dev, ino);
1407 		}
1408 	}
1409 	kfree(context);
1410 	return 0;
1411 }
1412 
1413 /* The inode's security attributes must be initialized before first use. */
inode_doinit_with_dentry(struct inode * inode,struct dentry * opt_dentry)1414 static int inode_doinit_with_dentry(struct inode *inode, struct dentry *opt_dentry)
1415 {
1416 	struct superblock_security_struct *sbsec = NULL;
1417 	struct inode_security_struct *isec = selinux_inode(inode);
1418 	u32 task_sid, sid = 0;
1419 	u16 sclass;
1420 	struct dentry *dentry;
1421 	int rc = 0;
1422 
1423 	if (isec->initialized == LABEL_INITIALIZED)
1424 		return 0;
1425 
1426 	spin_lock(&isec->lock);
1427 	if (isec->initialized == LABEL_INITIALIZED)
1428 		goto out_unlock;
1429 
1430 	if (isec->sclass == SECCLASS_FILE)
1431 		isec->sclass = inode_mode_to_security_class(inode->i_mode);
1432 
1433 	sbsec = selinux_superblock(inode->i_sb);
1434 	if (!(sbsec->flags & SE_SBINITIALIZED)) {
1435 		/* Defer initialization until selinux_complete_init,
1436 		   after the initial policy is loaded and the security
1437 		   server is ready to handle calls. */
1438 		spin_lock(&sbsec->isec_lock);
1439 		if (list_empty(&isec->list))
1440 			list_add(&isec->list, &sbsec->isec_head);
1441 		spin_unlock(&sbsec->isec_lock);
1442 		goto out_unlock;
1443 	}
1444 
1445 	sclass = isec->sclass;
1446 	task_sid = isec->task_sid;
1447 	sid = isec->sid;
1448 	isec->initialized = LABEL_PENDING;
1449 	spin_unlock(&isec->lock);
1450 
1451 	switch (sbsec->behavior) {
1452 	/*
1453 	 * In case of SECURITY_FS_USE_NATIVE we need to re-fetch the labels
1454 	 * via xattr when called from delayed_superblock_init().
1455 	 */
1456 	case SECURITY_FS_USE_NATIVE:
1457 	case SECURITY_FS_USE_XATTR:
1458 		if (!(inode->i_opflags & IOP_XATTR)) {
1459 			sid = sbsec->def_sid;
1460 			break;
1461 		}
1462 		/* Need a dentry, since the xattr API requires one.
1463 		   Life would be simpler if we could just pass the inode. */
1464 		if (opt_dentry) {
1465 			/* Called from d_instantiate or d_splice_alias. */
1466 			dentry = dget(opt_dentry);
1467 		} else {
1468 			/*
1469 			 * Called from selinux_complete_init, try to find a dentry.
1470 			 * Some filesystems really want a connected one, so try
1471 			 * that first.  We could split SECURITY_FS_USE_XATTR in
1472 			 * two, depending upon that...
1473 			 */
1474 			dentry = d_find_alias(inode);
1475 			if (!dentry)
1476 				dentry = d_find_any_alias(inode);
1477 		}
1478 		if (!dentry) {
1479 			/*
1480 			 * this is can be hit on boot when a file is accessed
1481 			 * before the policy is loaded.  When we load policy we
1482 			 * may find inodes that have no dentry on the
1483 			 * sbsec->isec_head list.  No reason to complain as these
1484 			 * will get fixed up the next time we go through
1485 			 * inode_doinit with a dentry, before these inodes could
1486 			 * be used again by userspace.
1487 			 */
1488 			goto out_invalid;
1489 		}
1490 
1491 		rc = inode_doinit_use_xattr(inode, dentry, sbsec->def_sid,
1492 					    &sid);
1493 		dput(dentry);
1494 		if (rc)
1495 			goto out;
1496 		break;
1497 	case SECURITY_FS_USE_TASK:
1498 		sid = task_sid;
1499 		break;
1500 	case SECURITY_FS_USE_TRANS:
1501 		/* Default to the fs SID. */
1502 		sid = sbsec->sid;
1503 
1504 		/* Try to obtain a transition SID. */
1505 		rc = security_transition_sid(task_sid, sid,
1506 					     sclass, NULL, &sid);
1507 		if (rc)
1508 			goto out;
1509 		break;
1510 	case SECURITY_FS_USE_MNTPOINT:
1511 		sid = sbsec->mntpoint_sid;
1512 		break;
1513 	default:
1514 		/* Default to the fs superblock SID. */
1515 		sid = sbsec->sid;
1516 
1517 		if ((sbsec->flags & SE_SBGENFS) &&
1518 		     (!S_ISLNK(inode->i_mode) ||
1519 		      selinux_policycap_genfs_seclabel_symlinks())) {
1520 			/* We must have a dentry to determine the label on
1521 			 * procfs inodes */
1522 			if (opt_dentry) {
1523 				/* Called from d_instantiate or
1524 				 * d_splice_alias. */
1525 				dentry = dget(opt_dentry);
1526 			} else {
1527 				/* Called from selinux_complete_init, try to
1528 				 * find a dentry.  Some filesystems really want
1529 				 * a connected one, so try that first.
1530 				 */
1531 				dentry = d_find_alias(inode);
1532 				if (!dentry)
1533 					dentry = d_find_any_alias(inode);
1534 			}
1535 			/*
1536 			 * This can be hit on boot when a file is accessed
1537 			 * before the policy is loaded.  When we load policy we
1538 			 * may find inodes that have no dentry on the
1539 			 * sbsec->isec_head list.  No reason to complain as
1540 			 * these will get fixed up the next time we go through
1541 			 * inode_doinit() with a dentry, before these inodes
1542 			 * could be used again by userspace.
1543 			 */
1544 			if (!dentry)
1545 				goto out_invalid;
1546 			rc = selinux_genfs_get_sid(dentry, sclass,
1547 						   sbsec->flags, &sid);
1548 			if (rc) {
1549 				dput(dentry);
1550 				goto out;
1551 			}
1552 
1553 			if ((sbsec->flags & SE_SBGENFS_XATTR) &&
1554 			    (inode->i_opflags & IOP_XATTR)) {
1555 				rc = inode_doinit_use_xattr(inode, dentry,
1556 							    sid, &sid);
1557 				if (rc) {
1558 					dput(dentry);
1559 					goto out;
1560 				}
1561 			}
1562 			dput(dentry);
1563 		}
1564 		break;
1565 	}
1566 
1567 out:
1568 	spin_lock(&isec->lock);
1569 	if (isec->initialized == LABEL_PENDING) {
1570 		if (rc) {
1571 			isec->initialized = LABEL_INVALID;
1572 			goto out_unlock;
1573 		}
1574 		isec->initialized = LABEL_INITIALIZED;
1575 		isec->sid = sid;
1576 	}
1577 
1578 out_unlock:
1579 	spin_unlock(&isec->lock);
1580 	return rc;
1581 
1582 out_invalid:
1583 	spin_lock(&isec->lock);
1584 	if (isec->initialized == LABEL_PENDING) {
1585 		isec->initialized = LABEL_INVALID;
1586 		isec->sid = sid;
1587 	}
1588 	spin_unlock(&isec->lock);
1589 	return 0;
1590 }
1591 
1592 /* Convert a Linux signal to an access vector. */
signal_to_av(int sig)1593 static inline u32 signal_to_av(int sig)
1594 {
1595 	u32 perm = 0;
1596 
1597 	switch (sig) {
1598 	case SIGCHLD:
1599 		/* Commonly granted from child to parent. */
1600 		perm = PROCESS__SIGCHLD;
1601 		break;
1602 	case SIGKILL:
1603 		/* Cannot be caught or ignored */
1604 		perm = PROCESS__SIGKILL;
1605 		break;
1606 	case SIGSTOP:
1607 		/* Cannot be caught or ignored */
1608 		perm = PROCESS__SIGSTOP;
1609 		break;
1610 	default:
1611 		/* All other signals. */
1612 		perm = PROCESS__SIGNAL;
1613 		break;
1614 	}
1615 
1616 	return perm;
1617 }
1618 
1619 #if CAP_LAST_CAP > 63
1620 #error Fix SELinux to handle capabilities > 63.
1621 #endif
1622 
1623 /* Check whether a task is allowed to use a capability. */
cred_has_capability(const struct cred * cred,int cap,unsigned int opts,bool initns)1624 static int cred_has_capability(const struct cred *cred,
1625 			       int cap, unsigned int opts, bool initns)
1626 {
1627 	struct common_audit_data ad;
1628 	struct av_decision avd;
1629 	u16 sclass;
1630 	u32 sid = cred_sid(cred);
1631 	u32 av = CAP_TO_MASK(cap);
1632 	int rc;
1633 
1634 	ad.type = LSM_AUDIT_DATA_CAP;
1635 	ad.u.cap = cap;
1636 
1637 	switch (CAP_TO_INDEX(cap)) {
1638 	case 0:
1639 		sclass = initns ? SECCLASS_CAPABILITY : SECCLASS_CAP_USERNS;
1640 		break;
1641 	case 1:
1642 		sclass = initns ? SECCLASS_CAPABILITY2 : SECCLASS_CAP2_USERNS;
1643 		break;
1644 	default:
1645 		pr_err("SELinux:  out of range capability %d\n", cap);
1646 		BUG();
1647 		return -EINVAL;
1648 	}
1649 
1650 	rc = avc_has_perm_noaudit(sid, sid, sclass, av, 0, &avd);
1651 	if (!(opts & CAP_OPT_NOAUDIT)) {
1652 		int rc2 = avc_audit(sid, sid, sclass, av, &avd, rc, &ad);
1653 		if (rc2)
1654 			return rc2;
1655 	}
1656 	return rc;
1657 }
1658 
1659 /* Check whether a task has a particular permission to an inode.
1660    The 'adp' parameter is optional and allows other audit
1661    data to be passed (e.g. the dentry). */
inode_has_perm(const struct cred * cred,struct inode * inode,u32 perms,struct common_audit_data * adp)1662 static int inode_has_perm(const struct cred *cred,
1663 			  struct inode *inode,
1664 			  u32 perms,
1665 			  struct common_audit_data *adp)
1666 {
1667 	struct inode_security_struct *isec;
1668 	u32 sid;
1669 
1670 	if (unlikely(IS_PRIVATE(inode)))
1671 		return 0;
1672 
1673 	sid = cred_sid(cred);
1674 	isec = selinux_inode(inode);
1675 
1676 	return avc_has_perm(sid, isec->sid, isec->sclass, perms, adp);
1677 }
1678 
1679 /* Same as inode_has_perm, but pass explicit audit data containing
1680    the dentry to help the auditing code to more easily generate the
1681    pathname if needed. */
dentry_has_perm(const struct cred * cred,struct dentry * dentry,u32 av)1682 static inline int dentry_has_perm(const struct cred *cred,
1683 				  struct dentry *dentry,
1684 				  u32 av)
1685 {
1686 	struct inode *inode = d_backing_inode(dentry);
1687 	struct common_audit_data ad;
1688 
1689 	ad.type = LSM_AUDIT_DATA_DENTRY;
1690 	ad.u.dentry = dentry;
1691 	__inode_security_revalidate(inode, dentry, true);
1692 	return inode_has_perm(cred, inode, av, &ad);
1693 }
1694 
1695 /* Same as inode_has_perm, but pass explicit audit data containing
1696    the path to help the auditing code to more easily generate the
1697    pathname if needed. */
path_has_perm(const struct cred * cred,const struct path * path,u32 av)1698 static inline int path_has_perm(const struct cred *cred,
1699 				const struct path *path,
1700 				u32 av)
1701 {
1702 	struct inode *inode = d_backing_inode(path->dentry);
1703 	struct common_audit_data ad;
1704 
1705 	ad.type = LSM_AUDIT_DATA_PATH;
1706 	ad.u.path = *path;
1707 	__inode_security_revalidate(inode, path->dentry, true);
1708 	return inode_has_perm(cred, inode, av, &ad);
1709 }
1710 
1711 /* Same as path_has_perm, but uses the inode from the file struct. */
file_path_has_perm(const struct cred * cred,struct file * file,u32 av)1712 static inline int file_path_has_perm(const struct cred *cred,
1713 				     struct file *file,
1714 				     u32 av)
1715 {
1716 	struct common_audit_data ad;
1717 
1718 	ad.type = LSM_AUDIT_DATA_FILE;
1719 	ad.u.file = file;
1720 	return inode_has_perm(cred, file_inode(file), av, &ad);
1721 }
1722 
1723 #ifdef CONFIG_BPF_SYSCALL
1724 static int bpf_fd_pass(const struct file *file, u32 sid);
1725 #endif
1726 
1727 /* Check whether a task can use an open file descriptor to
1728    access an inode in a given way.  Check access to the
1729    descriptor itself, and then use dentry_has_perm to
1730    check a particular permission to the file.
1731    Access to the descriptor is implicitly granted if it
1732    has the same SID as the process.  If av is zero, then
1733    access to the file is not checked, e.g. for cases
1734    where only the descriptor is affected like seek. */
file_has_perm(const struct cred * cred,struct file * file,u32 av)1735 static int file_has_perm(const struct cred *cred,
1736 			 struct file *file,
1737 			 u32 av)
1738 {
1739 	struct file_security_struct *fsec = selinux_file(file);
1740 	struct inode *inode = file_inode(file);
1741 	struct common_audit_data ad;
1742 	u32 sid = cred_sid(cred);
1743 	int rc;
1744 
1745 	ad.type = LSM_AUDIT_DATA_FILE;
1746 	ad.u.file = file;
1747 
1748 	if (sid != fsec->sid) {
1749 		rc = avc_has_perm(sid, fsec->sid,
1750 				  SECCLASS_FD,
1751 				  FD__USE,
1752 				  &ad);
1753 		if (rc)
1754 			goto out;
1755 	}
1756 
1757 #ifdef CONFIG_BPF_SYSCALL
1758 	rc = bpf_fd_pass(file, cred_sid(cred));
1759 	if (rc)
1760 		return rc;
1761 #endif
1762 
1763 	/* av is zero if only checking access to the descriptor. */
1764 	rc = 0;
1765 	if (av)
1766 		rc = inode_has_perm(cred, inode, av, &ad);
1767 
1768 out:
1769 	return rc;
1770 }
1771 
1772 /*
1773  * Determine the label for an inode that might be unioned.
1774  */
1775 static int
selinux_determine_inode_label(const struct task_security_struct * tsec,struct inode * dir,const struct qstr * name,u16 tclass,u32 * _new_isid)1776 selinux_determine_inode_label(const struct task_security_struct *tsec,
1777 				 struct inode *dir,
1778 				 const struct qstr *name, u16 tclass,
1779 				 u32 *_new_isid)
1780 {
1781 	const struct superblock_security_struct *sbsec =
1782 						selinux_superblock(dir->i_sb);
1783 
1784 	if ((sbsec->flags & SE_SBINITIALIZED) &&
1785 	    (sbsec->behavior == SECURITY_FS_USE_MNTPOINT)) {
1786 		*_new_isid = sbsec->mntpoint_sid;
1787 	} else if ((sbsec->flags & SBLABEL_MNT) &&
1788 		   tsec->create_sid) {
1789 		*_new_isid = tsec->create_sid;
1790 	} else {
1791 		const struct inode_security_struct *dsec = inode_security(dir);
1792 		return security_transition_sid(tsec->sid,
1793 					       dsec->sid, tclass,
1794 					       name, _new_isid);
1795 	}
1796 
1797 	return 0;
1798 }
1799 
1800 /* Check whether a task can create a file. */
may_create(struct inode * dir,struct dentry * dentry,u16 tclass)1801 static int may_create(struct inode *dir,
1802 		      struct dentry *dentry,
1803 		      u16 tclass)
1804 {
1805 	const struct task_security_struct *tsec = selinux_cred(current_cred());
1806 	struct inode_security_struct *dsec;
1807 	struct superblock_security_struct *sbsec;
1808 	u32 sid, newsid;
1809 	struct common_audit_data ad;
1810 	int rc;
1811 
1812 	dsec = inode_security(dir);
1813 	sbsec = selinux_superblock(dir->i_sb);
1814 
1815 	sid = tsec->sid;
1816 
1817 	ad.type = LSM_AUDIT_DATA_DENTRY;
1818 	ad.u.dentry = dentry;
1819 
1820 	rc = avc_has_perm(sid, dsec->sid, SECCLASS_DIR,
1821 			  DIR__ADD_NAME | DIR__SEARCH,
1822 			  &ad);
1823 	if (rc)
1824 		return rc;
1825 
1826 	rc = selinux_determine_inode_label(tsec, dir, &dentry->d_name, tclass,
1827 					   &newsid);
1828 	if (rc)
1829 		return rc;
1830 
1831 	rc = avc_has_perm(sid, newsid, tclass, FILE__CREATE, &ad);
1832 	if (rc)
1833 		return rc;
1834 
1835 	return avc_has_perm(newsid, sbsec->sid,
1836 			    SECCLASS_FILESYSTEM,
1837 			    FILESYSTEM__ASSOCIATE, &ad);
1838 }
1839 
1840 #define MAY_LINK	0
1841 #define MAY_UNLINK	1
1842 #define MAY_RMDIR	2
1843 
1844 /* Check whether a task can link, unlink, or rmdir a file/directory. */
may_link(struct inode * dir,struct dentry * dentry,int kind)1845 static int may_link(struct inode *dir,
1846 		    struct dentry *dentry,
1847 		    int kind)
1848 
1849 {
1850 	struct inode_security_struct *dsec, *isec;
1851 	struct common_audit_data ad;
1852 	u32 sid = current_sid();
1853 	u32 av;
1854 	int rc;
1855 
1856 	dsec = inode_security(dir);
1857 	isec = backing_inode_security(dentry);
1858 
1859 	ad.type = LSM_AUDIT_DATA_DENTRY;
1860 	ad.u.dentry = dentry;
1861 
1862 	av = DIR__SEARCH;
1863 	av |= (kind ? DIR__REMOVE_NAME : DIR__ADD_NAME);
1864 	rc = avc_has_perm(sid, dsec->sid, SECCLASS_DIR, av, &ad);
1865 	if (rc)
1866 		return rc;
1867 
1868 	switch (kind) {
1869 	case MAY_LINK:
1870 		av = FILE__LINK;
1871 		break;
1872 	case MAY_UNLINK:
1873 		av = FILE__UNLINK;
1874 		break;
1875 	case MAY_RMDIR:
1876 		av = DIR__RMDIR;
1877 		break;
1878 	default:
1879 		pr_warn("SELinux: %s:  unrecognized kind %d\n",
1880 			__func__, kind);
1881 		return 0;
1882 	}
1883 
1884 	rc = avc_has_perm(sid, isec->sid, isec->sclass, av, &ad);
1885 	return rc;
1886 }
1887 
may_rename(struct inode * old_dir,struct dentry * old_dentry,struct inode * new_dir,struct dentry * new_dentry)1888 static inline int may_rename(struct inode *old_dir,
1889 			     struct dentry *old_dentry,
1890 			     struct inode *new_dir,
1891 			     struct dentry *new_dentry)
1892 {
1893 	struct inode_security_struct *old_dsec, *new_dsec, *old_isec, *new_isec;
1894 	struct common_audit_data ad;
1895 	u32 sid = current_sid();
1896 	u32 av;
1897 	int old_is_dir, new_is_dir;
1898 	int rc;
1899 
1900 	old_dsec = inode_security(old_dir);
1901 	old_isec = backing_inode_security(old_dentry);
1902 	old_is_dir = d_is_dir(old_dentry);
1903 	new_dsec = inode_security(new_dir);
1904 
1905 	ad.type = LSM_AUDIT_DATA_DENTRY;
1906 
1907 	ad.u.dentry = old_dentry;
1908 	rc = avc_has_perm(sid, old_dsec->sid, SECCLASS_DIR,
1909 			  DIR__REMOVE_NAME | DIR__SEARCH, &ad);
1910 	if (rc)
1911 		return rc;
1912 	rc = avc_has_perm(sid, old_isec->sid,
1913 			  old_isec->sclass, FILE__RENAME, &ad);
1914 	if (rc)
1915 		return rc;
1916 	if (old_is_dir && new_dir != old_dir) {
1917 		rc = avc_has_perm(sid, old_isec->sid,
1918 				  old_isec->sclass, DIR__REPARENT, &ad);
1919 		if (rc)
1920 			return rc;
1921 	}
1922 
1923 	ad.u.dentry = new_dentry;
1924 	av = DIR__ADD_NAME | DIR__SEARCH;
1925 	if (d_is_positive(new_dentry))
1926 		av |= DIR__REMOVE_NAME;
1927 	rc = avc_has_perm(sid, new_dsec->sid, SECCLASS_DIR, av, &ad);
1928 	if (rc)
1929 		return rc;
1930 	if (d_is_positive(new_dentry)) {
1931 		new_isec = backing_inode_security(new_dentry);
1932 		new_is_dir = d_is_dir(new_dentry);
1933 		rc = avc_has_perm(sid, new_isec->sid,
1934 				  new_isec->sclass,
1935 				  (new_is_dir ? DIR__RMDIR : FILE__UNLINK), &ad);
1936 		if (rc)
1937 			return rc;
1938 	}
1939 
1940 	return 0;
1941 }
1942 
1943 /* Check whether a task can perform a filesystem operation. */
superblock_has_perm(const struct cred * cred,const struct super_block * sb,u32 perms,struct common_audit_data * ad)1944 static int superblock_has_perm(const struct cred *cred,
1945 			       const struct super_block *sb,
1946 			       u32 perms,
1947 			       struct common_audit_data *ad)
1948 {
1949 	struct superblock_security_struct *sbsec;
1950 	u32 sid = cred_sid(cred);
1951 
1952 	sbsec = selinux_superblock(sb);
1953 	return avc_has_perm(sid, sbsec->sid, SECCLASS_FILESYSTEM, perms, ad);
1954 }
1955 
1956 /* Convert a Linux mode and permission mask to an access vector. */
file_mask_to_av(int mode,int mask)1957 static inline u32 file_mask_to_av(int mode, int mask)
1958 {
1959 	u32 av = 0;
1960 
1961 	if (!S_ISDIR(mode)) {
1962 		if (mask & MAY_EXEC)
1963 			av |= FILE__EXECUTE;
1964 		if (mask & MAY_READ)
1965 			av |= FILE__READ;
1966 
1967 		if (mask & MAY_APPEND)
1968 			av |= FILE__APPEND;
1969 		else if (mask & MAY_WRITE)
1970 			av |= FILE__WRITE;
1971 
1972 	} else {
1973 		if (mask & MAY_EXEC)
1974 			av |= DIR__SEARCH;
1975 		if (mask & MAY_WRITE)
1976 			av |= DIR__WRITE;
1977 		if (mask & MAY_READ)
1978 			av |= DIR__READ;
1979 	}
1980 
1981 	return av;
1982 }
1983 
1984 /* Convert a Linux file to an access vector. */
file_to_av(const struct file * file)1985 static inline u32 file_to_av(const struct file *file)
1986 {
1987 	u32 av = 0;
1988 
1989 	if (file->f_mode & FMODE_READ)
1990 		av |= FILE__READ;
1991 	if (file->f_mode & FMODE_WRITE) {
1992 		if (file->f_flags & O_APPEND)
1993 			av |= FILE__APPEND;
1994 		else
1995 			av |= FILE__WRITE;
1996 	}
1997 	if (!av) {
1998 		/*
1999 		 * Special file opened with flags 3 for ioctl-only use.
2000 		 */
2001 		av = FILE__IOCTL;
2002 	}
2003 
2004 	return av;
2005 }
2006 
2007 /*
2008  * Convert a file to an access vector and include the correct
2009  * open permission.
2010  */
open_file_to_av(struct file * file)2011 static inline u32 open_file_to_av(struct file *file)
2012 {
2013 	u32 av = file_to_av(file);
2014 	struct inode *inode = file_inode(file);
2015 
2016 	if (selinux_policycap_openperm() &&
2017 	    inode->i_sb->s_magic != SOCKFS_MAGIC)
2018 		av |= FILE__OPEN;
2019 
2020 	return av;
2021 }
2022 
2023 /* Hook functions begin here. */
2024 
selinux_binder_set_context_mgr(const struct cred * mgr)2025 static int selinux_binder_set_context_mgr(const struct cred *mgr)
2026 {
2027 	return avc_has_perm(current_sid(), cred_sid(mgr), SECCLASS_BINDER,
2028 			    BINDER__SET_CONTEXT_MGR, NULL);
2029 }
2030 
selinux_binder_transaction(const struct cred * from,const struct cred * to)2031 static int selinux_binder_transaction(const struct cred *from,
2032 				      const struct cred *to)
2033 {
2034 	u32 mysid = current_sid();
2035 	u32 fromsid = cred_sid(from);
2036 	u32 tosid = cred_sid(to);
2037 	int rc;
2038 
2039 	if (mysid != fromsid) {
2040 		rc = avc_has_perm(mysid, fromsid, SECCLASS_BINDER,
2041 				  BINDER__IMPERSONATE, NULL);
2042 		if (rc)
2043 			return rc;
2044 	}
2045 
2046 	return avc_has_perm(fromsid, tosid,
2047 			    SECCLASS_BINDER, BINDER__CALL, NULL);
2048 }
2049 
selinux_binder_transfer_binder(const struct cred * from,const struct cred * to)2050 static int selinux_binder_transfer_binder(const struct cred *from,
2051 					  const struct cred *to)
2052 {
2053 	return avc_has_perm(cred_sid(from), cred_sid(to),
2054 			    SECCLASS_BINDER, BINDER__TRANSFER,
2055 			    NULL);
2056 }
2057 
selinux_binder_transfer_file(const struct cred * from,const struct cred * to,const struct file * file)2058 static int selinux_binder_transfer_file(const struct cred *from,
2059 					const struct cred *to,
2060 					const struct file *file)
2061 {
2062 	u32 sid = cred_sid(to);
2063 	struct file_security_struct *fsec = selinux_file(file);
2064 	struct dentry *dentry = file->f_path.dentry;
2065 	struct inode_security_struct *isec;
2066 	struct common_audit_data ad;
2067 	int rc;
2068 
2069 	ad.type = LSM_AUDIT_DATA_PATH;
2070 	ad.u.path = file->f_path;
2071 
2072 	if (sid != fsec->sid) {
2073 		rc = avc_has_perm(sid, fsec->sid,
2074 				  SECCLASS_FD,
2075 				  FD__USE,
2076 				  &ad);
2077 		if (rc)
2078 			return rc;
2079 	}
2080 
2081 #ifdef CONFIG_BPF_SYSCALL
2082 	rc = bpf_fd_pass(file, sid);
2083 	if (rc)
2084 		return rc;
2085 #endif
2086 
2087 	if (unlikely(IS_PRIVATE(d_backing_inode(dentry))))
2088 		return 0;
2089 
2090 	isec = backing_inode_security(dentry);
2091 	return avc_has_perm(sid, isec->sid, isec->sclass, file_to_av(file),
2092 			    &ad);
2093 }
2094 
selinux_ptrace_access_check(struct task_struct * child,unsigned int mode)2095 static int selinux_ptrace_access_check(struct task_struct *child,
2096 				       unsigned int mode)
2097 {
2098 	u32 sid = current_sid();
2099 	u32 csid = task_sid_obj(child);
2100 
2101 	if (mode & PTRACE_MODE_READ)
2102 		return avc_has_perm(sid, csid, SECCLASS_FILE, FILE__READ,
2103 				NULL);
2104 
2105 	return avc_has_perm(sid, csid, SECCLASS_PROCESS, PROCESS__PTRACE,
2106 			NULL);
2107 }
2108 
selinux_ptrace_traceme(struct task_struct * parent)2109 static int selinux_ptrace_traceme(struct task_struct *parent)
2110 {
2111 	return avc_has_perm(task_sid_obj(parent), task_sid_obj(current),
2112 			    SECCLASS_PROCESS, PROCESS__PTRACE, NULL);
2113 }
2114 
selinux_capget(const struct task_struct * target,kernel_cap_t * effective,kernel_cap_t * inheritable,kernel_cap_t * permitted)2115 static int selinux_capget(const struct task_struct *target, kernel_cap_t *effective,
2116 			  kernel_cap_t *inheritable, kernel_cap_t *permitted)
2117 {
2118 	return avc_has_perm(current_sid(), task_sid_obj(target),
2119 			SECCLASS_PROCESS, PROCESS__GETCAP, NULL);
2120 }
2121 
selinux_capset(struct cred * new,const struct cred * old,const kernel_cap_t * effective,const kernel_cap_t * inheritable,const kernel_cap_t * permitted)2122 static int selinux_capset(struct cred *new, const struct cred *old,
2123 			  const kernel_cap_t *effective,
2124 			  const kernel_cap_t *inheritable,
2125 			  const kernel_cap_t *permitted)
2126 {
2127 	return avc_has_perm(cred_sid(old), cred_sid(new), SECCLASS_PROCESS,
2128 			    PROCESS__SETCAP, NULL);
2129 }
2130 
2131 /*
2132  * (This comment used to live with the selinux_task_setuid hook,
2133  * which was removed).
2134  *
2135  * Since setuid only affects the current process, and since the SELinux
2136  * controls are not based on the Linux identity attributes, SELinux does not
2137  * need to control this operation.  However, SELinux does control the use of
2138  * the CAP_SETUID and CAP_SETGID capabilities using the capable hook.
2139  */
2140 
selinux_capable(const struct cred * cred,struct user_namespace * ns,int cap,unsigned int opts)2141 static int selinux_capable(const struct cred *cred, struct user_namespace *ns,
2142 			   int cap, unsigned int opts)
2143 {
2144 	return cred_has_capability(cred, cap, opts, ns == &init_user_ns);
2145 }
2146 
selinux_quotactl(int cmds,int type,int id,const struct super_block * sb)2147 static int selinux_quotactl(int cmds, int type, int id, const struct super_block *sb)
2148 {
2149 	const struct cred *cred = current_cred();
2150 	int rc = 0;
2151 
2152 	if (!sb)
2153 		return 0;
2154 
2155 	switch (cmds) {
2156 	case Q_SYNC:
2157 	case Q_QUOTAON:
2158 	case Q_QUOTAOFF:
2159 	case Q_SETINFO:
2160 	case Q_SETQUOTA:
2161 	case Q_XQUOTAOFF:
2162 	case Q_XQUOTAON:
2163 	case Q_XSETQLIM:
2164 		rc = superblock_has_perm(cred, sb, FILESYSTEM__QUOTAMOD, NULL);
2165 		break;
2166 	case Q_GETFMT:
2167 	case Q_GETINFO:
2168 	case Q_GETQUOTA:
2169 	case Q_XGETQUOTA:
2170 	case Q_XGETQSTAT:
2171 	case Q_XGETQSTATV:
2172 	case Q_XGETNEXTQUOTA:
2173 		rc = superblock_has_perm(cred, sb, FILESYSTEM__QUOTAGET, NULL);
2174 		break;
2175 	default:
2176 		rc = 0;  /* let the kernel handle invalid cmds */
2177 		break;
2178 	}
2179 	return rc;
2180 }
2181 
selinux_quota_on(struct dentry * dentry)2182 static int selinux_quota_on(struct dentry *dentry)
2183 {
2184 	const struct cred *cred = current_cred();
2185 
2186 	return dentry_has_perm(cred, dentry, FILE__QUOTAON);
2187 }
2188 
selinux_syslog(int type)2189 static int selinux_syslog(int type)
2190 {
2191 	switch (type) {
2192 	case SYSLOG_ACTION_READ_ALL:	/* Read last kernel messages */
2193 	case SYSLOG_ACTION_SIZE_BUFFER:	/* Return size of the log buffer */
2194 		return avc_has_perm(current_sid(), SECINITSID_KERNEL,
2195 				    SECCLASS_SYSTEM, SYSTEM__SYSLOG_READ, NULL);
2196 	case SYSLOG_ACTION_CONSOLE_OFF:	/* Disable logging to console */
2197 	case SYSLOG_ACTION_CONSOLE_ON:	/* Enable logging to console */
2198 	/* Set level of messages printed to console */
2199 	case SYSLOG_ACTION_CONSOLE_LEVEL:
2200 		return avc_has_perm(current_sid(), SECINITSID_KERNEL,
2201 				    SECCLASS_SYSTEM, SYSTEM__SYSLOG_CONSOLE,
2202 				    NULL);
2203 	}
2204 	/* All other syslog types */
2205 	return avc_has_perm(current_sid(), SECINITSID_KERNEL,
2206 			    SECCLASS_SYSTEM, SYSTEM__SYSLOG_MOD, NULL);
2207 }
2208 
2209 /*
2210  * Check permission for allocating a new virtual mapping. Returns
2211  * 0 if permission is granted, negative error code if not.
2212  *
2213  * Do not audit the selinux permission check, as this is applied to all
2214  * processes that allocate mappings.
2215  */
selinux_vm_enough_memory(struct mm_struct * mm,long pages)2216 static int selinux_vm_enough_memory(struct mm_struct *mm, long pages)
2217 {
2218 	return cred_has_capability(current_cred(), CAP_SYS_ADMIN,
2219 				   CAP_OPT_NOAUDIT, true);
2220 }
2221 
2222 /* binprm security operations */
2223 
ptrace_parent_sid(void)2224 static u32 ptrace_parent_sid(void)
2225 {
2226 	u32 sid = 0;
2227 	struct task_struct *tracer;
2228 
2229 	rcu_read_lock();
2230 	tracer = ptrace_parent(current);
2231 	if (tracer)
2232 		sid = task_sid_obj(tracer);
2233 	rcu_read_unlock();
2234 
2235 	return sid;
2236 }
2237 
check_nnp_nosuid(const struct linux_binprm * bprm,const struct task_security_struct * old_tsec,const struct task_security_struct * new_tsec)2238 static int check_nnp_nosuid(const struct linux_binprm *bprm,
2239 			    const struct task_security_struct *old_tsec,
2240 			    const struct task_security_struct *new_tsec)
2241 {
2242 	int nnp = (bprm->unsafe & LSM_UNSAFE_NO_NEW_PRIVS);
2243 	int nosuid = !mnt_may_suid(bprm->file->f_path.mnt);
2244 	int rc;
2245 	u32 av;
2246 
2247 	if (!nnp && !nosuid)
2248 		return 0; /* neither NNP nor nosuid */
2249 
2250 	if (new_tsec->sid == old_tsec->sid)
2251 		return 0; /* No change in credentials */
2252 
2253 	/*
2254 	 * If the policy enables the nnp_nosuid_transition policy capability,
2255 	 * then we permit transitions under NNP or nosuid if the
2256 	 * policy allows the corresponding permission between
2257 	 * the old and new contexts.
2258 	 */
2259 	if (selinux_policycap_nnp_nosuid_transition()) {
2260 		av = 0;
2261 		if (nnp)
2262 			av |= PROCESS2__NNP_TRANSITION;
2263 		if (nosuid)
2264 			av |= PROCESS2__NOSUID_TRANSITION;
2265 		rc = avc_has_perm(old_tsec->sid, new_tsec->sid,
2266 				  SECCLASS_PROCESS2, av, NULL);
2267 		if (!rc)
2268 			return 0;
2269 	}
2270 
2271 	/*
2272 	 * We also permit NNP or nosuid transitions to bounded SIDs,
2273 	 * i.e. SIDs that are guaranteed to only be allowed a subset
2274 	 * of the permissions of the current SID.
2275 	 */
2276 	rc = security_bounded_transition(old_tsec->sid,
2277 					 new_tsec->sid);
2278 	if (!rc)
2279 		return 0;
2280 
2281 	/*
2282 	 * On failure, preserve the errno values for NNP vs nosuid.
2283 	 * NNP:  Operation not permitted for caller.
2284 	 * nosuid:  Permission denied to file.
2285 	 */
2286 	if (nnp)
2287 		return -EPERM;
2288 	return -EACCES;
2289 }
2290 
selinux_bprm_creds_for_exec(struct linux_binprm * bprm)2291 static int selinux_bprm_creds_for_exec(struct linux_binprm *bprm)
2292 {
2293 	const struct task_security_struct *old_tsec;
2294 	struct task_security_struct *new_tsec;
2295 	struct inode_security_struct *isec;
2296 	struct common_audit_data ad;
2297 	struct inode *inode = file_inode(bprm->file);
2298 	int rc;
2299 
2300 	/* SELinux context only depends on initial program or script and not
2301 	 * the script interpreter */
2302 
2303 	old_tsec = selinux_cred(current_cred());
2304 	new_tsec = selinux_cred(bprm->cred);
2305 	isec = inode_security(inode);
2306 
2307 	/* Default to the current task SID. */
2308 	new_tsec->sid = old_tsec->sid;
2309 	new_tsec->osid = old_tsec->sid;
2310 
2311 	/* Reset fs, key, and sock SIDs on execve. */
2312 	new_tsec->create_sid = 0;
2313 	new_tsec->keycreate_sid = 0;
2314 	new_tsec->sockcreate_sid = 0;
2315 
2316 	/*
2317 	 * Before policy is loaded, label any task outside kernel space
2318 	 * as SECINITSID_INIT, so that any userspace tasks surviving from
2319 	 * early boot end up with a label different from SECINITSID_KERNEL
2320 	 * (if the policy chooses to set SECINITSID_INIT != SECINITSID_KERNEL).
2321 	 */
2322 	if (!selinux_initialized()) {
2323 		new_tsec->sid = SECINITSID_INIT;
2324 		/* also clear the exec_sid just in case */
2325 		new_tsec->exec_sid = 0;
2326 		return 0;
2327 	}
2328 
2329 	if (old_tsec->exec_sid) {
2330 		new_tsec->sid = old_tsec->exec_sid;
2331 		/* Reset exec SID on execve. */
2332 		new_tsec->exec_sid = 0;
2333 
2334 		/* Fail on NNP or nosuid if not an allowed transition. */
2335 		rc = check_nnp_nosuid(bprm, old_tsec, new_tsec);
2336 		if (rc)
2337 			return rc;
2338 	} else {
2339 		/* Check for a default transition on this program. */
2340 		rc = security_transition_sid(old_tsec->sid,
2341 					     isec->sid, SECCLASS_PROCESS, NULL,
2342 					     &new_tsec->sid);
2343 		if (rc)
2344 			return rc;
2345 
2346 		/*
2347 		 * Fallback to old SID on NNP or nosuid if not an allowed
2348 		 * transition.
2349 		 */
2350 		rc = check_nnp_nosuid(bprm, old_tsec, new_tsec);
2351 		if (rc)
2352 			new_tsec->sid = old_tsec->sid;
2353 	}
2354 
2355 	ad.type = LSM_AUDIT_DATA_FILE;
2356 	ad.u.file = bprm->file;
2357 
2358 	if (new_tsec->sid == old_tsec->sid) {
2359 		rc = avc_has_perm(old_tsec->sid, isec->sid,
2360 				  SECCLASS_FILE, FILE__EXECUTE_NO_TRANS, &ad);
2361 		if (rc)
2362 			return rc;
2363 	} else {
2364 		/* Check permissions for the transition. */
2365 		rc = avc_has_perm(old_tsec->sid, new_tsec->sid,
2366 				  SECCLASS_PROCESS, PROCESS__TRANSITION, &ad);
2367 		if (rc)
2368 			return rc;
2369 
2370 		rc = avc_has_perm(new_tsec->sid, isec->sid,
2371 				  SECCLASS_FILE, FILE__ENTRYPOINT, &ad);
2372 		if (rc)
2373 			return rc;
2374 
2375 		/* Check for shared state */
2376 		if (bprm->unsafe & LSM_UNSAFE_SHARE) {
2377 			rc = avc_has_perm(old_tsec->sid, new_tsec->sid,
2378 					  SECCLASS_PROCESS, PROCESS__SHARE,
2379 					  NULL);
2380 			if (rc)
2381 				return -EPERM;
2382 		}
2383 
2384 		/* Make sure that anyone attempting to ptrace over a task that
2385 		 * changes its SID has the appropriate permit */
2386 		if (bprm->unsafe & LSM_UNSAFE_PTRACE) {
2387 			u32 ptsid = ptrace_parent_sid();
2388 			if (ptsid != 0) {
2389 				rc = avc_has_perm(ptsid, new_tsec->sid,
2390 						  SECCLASS_PROCESS,
2391 						  PROCESS__PTRACE, NULL);
2392 				if (rc)
2393 					return -EPERM;
2394 			}
2395 		}
2396 
2397 		/* Clear any possibly unsafe personality bits on exec: */
2398 		bprm->per_clear |= PER_CLEAR_ON_SETID;
2399 
2400 		/* Enable secure mode for SIDs transitions unless
2401 		   the noatsecure permission is granted between
2402 		   the two SIDs, i.e. ahp returns 0. */
2403 		rc = avc_has_perm(old_tsec->sid, new_tsec->sid,
2404 				  SECCLASS_PROCESS, PROCESS__NOATSECURE,
2405 				  NULL);
2406 		bprm->secureexec |= !!rc;
2407 	}
2408 
2409 	return 0;
2410 }
2411 
match_file(const void * p,struct file * file,unsigned fd)2412 static int match_file(const void *p, struct file *file, unsigned fd)
2413 {
2414 	return file_has_perm(p, file, file_to_av(file)) ? fd + 1 : 0;
2415 }
2416 
2417 /* Derived from fs/exec.c:flush_old_files. */
flush_unauthorized_files(const struct cred * cred,struct files_struct * files)2418 static inline void flush_unauthorized_files(const struct cred *cred,
2419 					    struct files_struct *files)
2420 {
2421 	struct file *file, *devnull = NULL;
2422 	struct tty_struct *tty;
2423 	int drop_tty = 0;
2424 	unsigned n;
2425 
2426 	tty = get_current_tty();
2427 	if (tty) {
2428 		spin_lock(&tty->files_lock);
2429 		if (!list_empty(&tty->tty_files)) {
2430 			struct tty_file_private *file_priv;
2431 
2432 			/* Revalidate access to controlling tty.
2433 			   Use file_path_has_perm on the tty path directly
2434 			   rather than using file_has_perm, as this particular
2435 			   open file may belong to another process and we are
2436 			   only interested in the inode-based check here. */
2437 			file_priv = list_first_entry(&tty->tty_files,
2438 						struct tty_file_private, list);
2439 			file = file_priv->file;
2440 			if (file_path_has_perm(cred, file, FILE__READ | FILE__WRITE))
2441 				drop_tty = 1;
2442 		}
2443 		spin_unlock(&tty->files_lock);
2444 		tty_kref_put(tty);
2445 	}
2446 	/* Reset controlling tty. */
2447 	if (drop_tty)
2448 		no_tty();
2449 
2450 	/* Revalidate access to inherited open files. */
2451 	n = iterate_fd(files, 0, match_file, cred);
2452 	if (!n) /* none found? */
2453 		return;
2454 
2455 	devnull = dentry_open(&selinux_null, O_RDWR, cred);
2456 	if (IS_ERR(devnull))
2457 		devnull = NULL;
2458 	/* replace all the matching ones with this */
2459 	do {
2460 		replace_fd(n - 1, devnull, 0);
2461 	} while ((n = iterate_fd(files, n, match_file, cred)) != 0);
2462 	if (devnull)
2463 		fput(devnull);
2464 }
2465 
2466 /*
2467  * Prepare a process for imminent new credential changes due to exec
2468  */
selinux_bprm_committing_creds(const struct linux_binprm * bprm)2469 static void selinux_bprm_committing_creds(const struct linux_binprm *bprm)
2470 {
2471 	struct task_security_struct *new_tsec;
2472 	struct rlimit *rlim, *initrlim;
2473 	int rc, i;
2474 
2475 	new_tsec = selinux_cred(bprm->cred);
2476 	if (new_tsec->sid == new_tsec->osid)
2477 		return;
2478 
2479 	/* Close files for which the new task SID is not authorized. */
2480 	flush_unauthorized_files(bprm->cred, current->files);
2481 
2482 	/* Always clear parent death signal on SID transitions. */
2483 	current->pdeath_signal = 0;
2484 
2485 	/* Check whether the new SID can inherit resource limits from the old
2486 	 * SID.  If not, reset all soft limits to the lower of the current
2487 	 * task's hard limit and the init task's soft limit.
2488 	 *
2489 	 * Note that the setting of hard limits (even to lower them) can be
2490 	 * controlled by the setrlimit check.  The inclusion of the init task's
2491 	 * soft limit into the computation is to avoid resetting soft limits
2492 	 * higher than the default soft limit for cases where the default is
2493 	 * lower than the hard limit, e.g. RLIMIT_CORE or RLIMIT_STACK.
2494 	 */
2495 	rc = avc_has_perm(new_tsec->osid, new_tsec->sid, SECCLASS_PROCESS,
2496 			  PROCESS__RLIMITINH, NULL);
2497 	if (rc) {
2498 		/* protect against do_prlimit() */
2499 		task_lock(current);
2500 		for (i = 0; i < RLIM_NLIMITS; i++) {
2501 			rlim = current->signal->rlim + i;
2502 			initrlim = init_task.signal->rlim + i;
2503 			rlim->rlim_cur = min(rlim->rlim_max, initrlim->rlim_cur);
2504 		}
2505 		task_unlock(current);
2506 		if (IS_ENABLED(CONFIG_POSIX_TIMERS))
2507 			update_rlimit_cpu(current, rlimit(RLIMIT_CPU));
2508 	}
2509 }
2510 
2511 /*
2512  * Clean up the process immediately after the installation of new credentials
2513  * due to exec
2514  */
selinux_bprm_committed_creds(const struct linux_binprm * bprm)2515 static void selinux_bprm_committed_creds(const struct linux_binprm *bprm)
2516 {
2517 	const struct task_security_struct *tsec = selinux_cred(current_cred());
2518 	u32 osid, sid;
2519 	int rc;
2520 
2521 	osid = tsec->osid;
2522 	sid = tsec->sid;
2523 
2524 	if (sid == osid)
2525 		return;
2526 
2527 	/* Check whether the new SID can inherit signal state from the old SID.
2528 	 * If not, clear itimers to avoid subsequent signal generation and
2529 	 * flush and unblock signals.
2530 	 *
2531 	 * This must occur _after_ the task SID has been updated so that any
2532 	 * kill done after the flush will be checked against the new SID.
2533 	 */
2534 	rc = avc_has_perm(osid, sid, SECCLASS_PROCESS, PROCESS__SIGINH, NULL);
2535 	if (rc) {
2536 		clear_itimer();
2537 
2538 		spin_lock_irq(&unrcu_pointer(current->sighand)->siglock);
2539 		if (!fatal_signal_pending(current)) {
2540 			flush_sigqueue(&current->pending);
2541 			flush_sigqueue(&current->signal->shared_pending);
2542 			flush_signal_handlers(current, 1);
2543 			sigemptyset(&current->blocked);
2544 			recalc_sigpending();
2545 		}
2546 		spin_unlock_irq(&unrcu_pointer(current->sighand)->siglock);
2547 	}
2548 
2549 	/* Wake up the parent if it is waiting so that it can recheck
2550 	 * wait permission to the new task SID. */
2551 	read_lock(&tasklist_lock);
2552 	__wake_up_parent(current, unrcu_pointer(current->real_parent));
2553 	read_unlock(&tasklist_lock);
2554 }
2555 
2556 /* superblock security operations */
2557 
selinux_sb_alloc_security(struct super_block * sb)2558 static int selinux_sb_alloc_security(struct super_block *sb)
2559 {
2560 	struct superblock_security_struct *sbsec = selinux_superblock(sb);
2561 
2562 	mutex_init(&sbsec->lock);
2563 	INIT_LIST_HEAD(&sbsec->isec_head);
2564 	spin_lock_init(&sbsec->isec_lock);
2565 	sbsec->sid = SECINITSID_UNLABELED;
2566 	sbsec->def_sid = SECINITSID_FILE;
2567 	sbsec->mntpoint_sid = SECINITSID_UNLABELED;
2568 
2569 	return 0;
2570 }
2571 
opt_len(const char * s)2572 static inline int opt_len(const char *s)
2573 {
2574 	bool open_quote = false;
2575 	int len;
2576 	char c;
2577 
2578 	for (len = 0; (c = s[len]) != '\0'; len++) {
2579 		if (c == '"')
2580 			open_quote = !open_quote;
2581 		if (c == ',' && !open_quote)
2582 			break;
2583 	}
2584 	return len;
2585 }
2586 
selinux_sb_eat_lsm_opts(char * options,void ** mnt_opts)2587 static int selinux_sb_eat_lsm_opts(char *options, void **mnt_opts)
2588 {
2589 	char *from = options;
2590 	char *to = options;
2591 	bool first = true;
2592 	int rc;
2593 
2594 	while (1) {
2595 		int len = opt_len(from);
2596 		int token;
2597 		char *arg = NULL;
2598 
2599 		token = match_opt_prefix(from, len, &arg);
2600 
2601 		if (token != Opt_error) {
2602 			char *p, *q;
2603 
2604 			/* strip quotes */
2605 			if (arg) {
2606 				for (p = q = arg; p < from + len; p++) {
2607 					char c = *p;
2608 					if (c != '"')
2609 						*q++ = c;
2610 				}
2611 				arg = kmemdup_nul(arg, q - arg, GFP_KERNEL);
2612 				if (!arg) {
2613 					rc = -ENOMEM;
2614 					goto free_opt;
2615 				}
2616 			}
2617 			rc = selinux_add_opt(token, arg, mnt_opts);
2618 			kfree(arg);
2619 			arg = NULL;
2620 			if (unlikely(rc)) {
2621 				goto free_opt;
2622 			}
2623 		} else {
2624 			if (!first) {	// copy with preceding comma
2625 				from--;
2626 				len++;
2627 			}
2628 			if (to != from)
2629 				memmove(to, from, len);
2630 			to += len;
2631 			first = false;
2632 		}
2633 		if (!from[len])
2634 			break;
2635 		from += len + 1;
2636 	}
2637 	*to = '\0';
2638 	return 0;
2639 
2640 free_opt:
2641 	if (*mnt_opts) {
2642 		selinux_free_mnt_opts(*mnt_opts);
2643 		*mnt_opts = NULL;
2644 	}
2645 	return rc;
2646 }
2647 
selinux_sb_mnt_opts_compat(struct super_block * sb,void * mnt_opts)2648 static int selinux_sb_mnt_opts_compat(struct super_block *sb, void *mnt_opts)
2649 {
2650 	struct selinux_mnt_opts *opts = mnt_opts;
2651 	struct superblock_security_struct *sbsec = selinux_superblock(sb);
2652 
2653 	/*
2654 	 * Superblock not initialized (i.e. no options) - reject if any
2655 	 * options specified, otherwise accept.
2656 	 */
2657 	if (!(sbsec->flags & SE_SBINITIALIZED))
2658 		return opts ? 1 : 0;
2659 
2660 	/*
2661 	 * Superblock initialized and no options specified - reject if
2662 	 * superblock has any options set, otherwise accept.
2663 	 */
2664 	if (!opts)
2665 		return (sbsec->flags & SE_MNTMASK) ? 1 : 0;
2666 
2667 	if (opts->fscontext_sid) {
2668 		if (bad_option(sbsec, FSCONTEXT_MNT, sbsec->sid,
2669 			       opts->fscontext_sid))
2670 			return 1;
2671 	}
2672 	if (opts->context_sid) {
2673 		if (bad_option(sbsec, CONTEXT_MNT, sbsec->mntpoint_sid,
2674 			       opts->context_sid))
2675 			return 1;
2676 	}
2677 	if (opts->rootcontext_sid) {
2678 		struct inode_security_struct *root_isec;
2679 
2680 		root_isec = backing_inode_security(sb->s_root);
2681 		if (bad_option(sbsec, ROOTCONTEXT_MNT, root_isec->sid,
2682 			       opts->rootcontext_sid))
2683 			return 1;
2684 	}
2685 	if (opts->defcontext_sid) {
2686 		if (bad_option(sbsec, DEFCONTEXT_MNT, sbsec->def_sid,
2687 			       opts->defcontext_sid))
2688 			return 1;
2689 	}
2690 	return 0;
2691 }
2692 
selinux_sb_remount(struct super_block * sb,void * mnt_opts)2693 static int selinux_sb_remount(struct super_block *sb, void *mnt_opts)
2694 {
2695 	struct selinux_mnt_opts *opts = mnt_opts;
2696 	struct superblock_security_struct *sbsec = selinux_superblock(sb);
2697 
2698 	if (!(sbsec->flags & SE_SBINITIALIZED))
2699 		return 0;
2700 
2701 	if (!opts)
2702 		return 0;
2703 
2704 	if (opts->fscontext_sid) {
2705 		if (bad_option(sbsec, FSCONTEXT_MNT, sbsec->sid,
2706 			       opts->fscontext_sid))
2707 			goto out_bad_option;
2708 	}
2709 	if (opts->context_sid) {
2710 		if (bad_option(sbsec, CONTEXT_MNT, sbsec->mntpoint_sid,
2711 			       opts->context_sid))
2712 			goto out_bad_option;
2713 	}
2714 	if (opts->rootcontext_sid) {
2715 		struct inode_security_struct *root_isec;
2716 		root_isec = backing_inode_security(sb->s_root);
2717 		if (bad_option(sbsec, ROOTCONTEXT_MNT, root_isec->sid,
2718 			       opts->rootcontext_sid))
2719 			goto out_bad_option;
2720 	}
2721 	if (opts->defcontext_sid) {
2722 		if (bad_option(sbsec, DEFCONTEXT_MNT, sbsec->def_sid,
2723 			       opts->defcontext_sid))
2724 			goto out_bad_option;
2725 	}
2726 	return 0;
2727 
2728 out_bad_option:
2729 	pr_warn("SELinux: unable to change security options "
2730 	       "during remount (dev %s, type=%s)\n", sb->s_id,
2731 	       sb->s_type->name);
2732 	return -EINVAL;
2733 }
2734 
selinux_sb_kern_mount(const struct super_block * sb)2735 static int selinux_sb_kern_mount(const struct super_block *sb)
2736 {
2737 	const struct cred *cred = current_cred();
2738 	struct common_audit_data ad;
2739 
2740 	ad.type = LSM_AUDIT_DATA_DENTRY;
2741 	ad.u.dentry = sb->s_root;
2742 	return superblock_has_perm(cred, sb, FILESYSTEM__MOUNT, &ad);
2743 }
2744 
selinux_sb_statfs(struct dentry * dentry)2745 static int selinux_sb_statfs(struct dentry *dentry)
2746 {
2747 	const struct cred *cred = current_cred();
2748 	struct common_audit_data ad;
2749 
2750 	ad.type = LSM_AUDIT_DATA_DENTRY;
2751 	ad.u.dentry = dentry->d_sb->s_root;
2752 	return superblock_has_perm(cred, dentry->d_sb, FILESYSTEM__GETATTR, &ad);
2753 }
2754 
selinux_mount(const char * dev_name,const struct path * path,const char * type,unsigned long flags,void * data)2755 static int selinux_mount(const char *dev_name,
2756 			 const struct path *path,
2757 			 const char *type,
2758 			 unsigned long flags,
2759 			 void *data)
2760 {
2761 	const struct cred *cred = current_cred();
2762 
2763 	if (flags & MS_REMOUNT)
2764 		return superblock_has_perm(cred, path->dentry->d_sb,
2765 					   FILESYSTEM__REMOUNT, NULL);
2766 	else
2767 		return path_has_perm(cred, path, FILE__MOUNTON);
2768 }
2769 
selinux_move_mount(const struct path * from_path,const struct path * to_path)2770 static int selinux_move_mount(const struct path *from_path,
2771 			      const struct path *to_path)
2772 {
2773 	const struct cred *cred = current_cred();
2774 
2775 	return path_has_perm(cred, to_path, FILE__MOUNTON);
2776 }
2777 
selinux_umount(struct vfsmount * mnt,int flags)2778 static int selinux_umount(struct vfsmount *mnt, int flags)
2779 {
2780 	const struct cred *cred = current_cred();
2781 
2782 	return superblock_has_perm(cred, mnt->mnt_sb,
2783 				   FILESYSTEM__UNMOUNT, NULL);
2784 }
2785 
selinux_fs_context_submount(struct fs_context * fc,struct super_block * reference)2786 static int selinux_fs_context_submount(struct fs_context *fc,
2787 				   struct super_block *reference)
2788 {
2789 	const struct superblock_security_struct *sbsec = selinux_superblock(reference);
2790 	struct selinux_mnt_opts *opts;
2791 
2792 	/*
2793 	 * Ensure that fc->security remains NULL when no options are set
2794 	 * as expected by selinux_set_mnt_opts().
2795 	 */
2796 	if (!(sbsec->flags & (FSCONTEXT_MNT|CONTEXT_MNT|DEFCONTEXT_MNT)))
2797 		return 0;
2798 
2799 	opts = kzalloc(sizeof(*opts), GFP_KERNEL);
2800 	if (!opts)
2801 		return -ENOMEM;
2802 
2803 	if (sbsec->flags & FSCONTEXT_MNT)
2804 		opts->fscontext_sid = sbsec->sid;
2805 	if (sbsec->flags & CONTEXT_MNT)
2806 		opts->context_sid = sbsec->mntpoint_sid;
2807 	if (sbsec->flags & DEFCONTEXT_MNT)
2808 		opts->defcontext_sid = sbsec->def_sid;
2809 	fc->security = opts;
2810 	return 0;
2811 }
2812 
selinux_fs_context_dup(struct fs_context * fc,struct fs_context * src_fc)2813 static int selinux_fs_context_dup(struct fs_context *fc,
2814 				  struct fs_context *src_fc)
2815 {
2816 	const struct selinux_mnt_opts *src = src_fc->security;
2817 
2818 	if (!src)
2819 		return 0;
2820 
2821 	fc->security = kmemdup(src, sizeof(*src), GFP_KERNEL);
2822 	return fc->security ? 0 : -ENOMEM;
2823 }
2824 
2825 static const struct fs_parameter_spec selinux_fs_parameters[] = {
2826 	fsparam_string(CONTEXT_STR,	Opt_context),
2827 	fsparam_string(DEFCONTEXT_STR,	Opt_defcontext),
2828 	fsparam_string(FSCONTEXT_STR,	Opt_fscontext),
2829 	fsparam_string(ROOTCONTEXT_STR,	Opt_rootcontext),
2830 	fsparam_flag  (SECLABEL_STR,	Opt_seclabel),
2831 	{}
2832 };
2833 
selinux_fs_context_parse_param(struct fs_context * fc,struct fs_parameter * param)2834 static int selinux_fs_context_parse_param(struct fs_context *fc,
2835 					  struct fs_parameter *param)
2836 {
2837 	struct fs_parse_result result;
2838 	int opt;
2839 
2840 	opt = fs_parse(fc, selinux_fs_parameters, param, &result);
2841 	if (opt < 0)
2842 		return opt;
2843 
2844 	return selinux_add_opt(opt, param->string, &fc->security);
2845 }
2846 
2847 /* inode security operations */
2848 
selinux_inode_alloc_security(struct inode * inode)2849 static int selinux_inode_alloc_security(struct inode *inode)
2850 {
2851 	struct inode_security_struct *isec = selinux_inode(inode);
2852 	u32 sid = current_sid();
2853 
2854 	spin_lock_init(&isec->lock);
2855 	INIT_LIST_HEAD(&isec->list);
2856 	isec->inode = inode;
2857 	isec->sid = SECINITSID_UNLABELED;
2858 	isec->sclass = SECCLASS_FILE;
2859 	isec->task_sid = sid;
2860 	isec->initialized = LABEL_INVALID;
2861 
2862 	return 0;
2863 }
2864 
selinux_inode_free_security(struct inode * inode)2865 static void selinux_inode_free_security(struct inode *inode)
2866 {
2867 	inode_free_security(inode);
2868 }
2869 
selinux_dentry_init_security(struct dentry * dentry,int mode,const struct qstr * name,const char ** xattr_name,struct lsm_context * cp)2870 static int selinux_dentry_init_security(struct dentry *dentry, int mode,
2871 					const struct qstr *name,
2872 					const char **xattr_name,
2873 					struct lsm_context *cp)
2874 {
2875 	u32 newsid;
2876 	int rc;
2877 
2878 	rc = selinux_determine_inode_label(selinux_cred(current_cred()),
2879 					   d_inode(dentry->d_parent), name,
2880 					   inode_mode_to_security_class(mode),
2881 					   &newsid);
2882 	if (rc)
2883 		return rc;
2884 
2885 	if (xattr_name)
2886 		*xattr_name = XATTR_NAME_SELINUX;
2887 
2888 	cp->id = LSM_ID_SELINUX;
2889 	return security_sid_to_context(newsid, &cp->context, &cp->len);
2890 }
2891 
selinux_dentry_create_files_as(struct dentry * dentry,int mode,struct qstr * name,const struct cred * old,struct cred * new)2892 static int selinux_dentry_create_files_as(struct dentry *dentry, int mode,
2893 					  struct qstr *name,
2894 					  const struct cred *old,
2895 					  struct cred *new)
2896 {
2897 	u32 newsid;
2898 	int rc;
2899 	struct task_security_struct *tsec;
2900 
2901 	rc = selinux_determine_inode_label(selinux_cred(old),
2902 					   d_inode(dentry->d_parent), name,
2903 					   inode_mode_to_security_class(mode),
2904 					   &newsid);
2905 	if (rc)
2906 		return rc;
2907 
2908 	tsec = selinux_cred(new);
2909 	tsec->create_sid = newsid;
2910 	return 0;
2911 }
2912 
selinux_inode_init_security(struct inode * inode,struct inode * dir,const struct qstr * qstr,struct xattr * xattrs,int * xattr_count)2913 static int selinux_inode_init_security(struct inode *inode, struct inode *dir,
2914 				       const struct qstr *qstr,
2915 				       struct xattr *xattrs, int *xattr_count)
2916 {
2917 	const struct task_security_struct *tsec = selinux_cred(current_cred());
2918 	struct superblock_security_struct *sbsec;
2919 	struct xattr *xattr = lsm_get_xattr_slot(xattrs, xattr_count);
2920 	u32 newsid, clen;
2921 	u16 newsclass;
2922 	int rc;
2923 	char *context;
2924 
2925 	sbsec = selinux_superblock(dir->i_sb);
2926 
2927 	newsid = tsec->create_sid;
2928 	newsclass = inode_mode_to_security_class(inode->i_mode);
2929 	rc = selinux_determine_inode_label(tsec, dir, qstr, newsclass, &newsid);
2930 	if (rc)
2931 		return rc;
2932 
2933 	/* Possibly defer initialization to selinux_complete_init. */
2934 	if (sbsec->flags & SE_SBINITIALIZED) {
2935 		struct inode_security_struct *isec = selinux_inode(inode);
2936 		isec->sclass = newsclass;
2937 		isec->sid = newsid;
2938 		isec->initialized = LABEL_INITIALIZED;
2939 	}
2940 
2941 	if (!selinux_initialized() ||
2942 	    !(sbsec->flags & SBLABEL_MNT))
2943 		return -EOPNOTSUPP;
2944 
2945 	if (xattr) {
2946 		rc = security_sid_to_context_force(newsid,
2947 						   &context, &clen);
2948 		if (rc)
2949 			return rc;
2950 		xattr->value = context;
2951 		xattr->value_len = clen;
2952 		xattr->name = XATTR_SELINUX_SUFFIX;
2953 	}
2954 
2955 	return 0;
2956 }
2957 
selinux_inode_init_security_anon(struct inode * inode,const struct qstr * name,const struct inode * context_inode)2958 static int selinux_inode_init_security_anon(struct inode *inode,
2959 					    const struct qstr *name,
2960 					    const struct inode *context_inode)
2961 {
2962 	u32 sid = current_sid();
2963 	struct common_audit_data ad;
2964 	struct inode_security_struct *isec;
2965 	int rc;
2966 
2967 	if (unlikely(!selinux_initialized()))
2968 		return 0;
2969 
2970 	isec = selinux_inode(inode);
2971 
2972 	/*
2973 	 * We only get here once per ephemeral inode.  The inode has
2974 	 * been initialized via inode_alloc_security but is otherwise
2975 	 * untouched.
2976 	 */
2977 
2978 	if (context_inode) {
2979 		struct inode_security_struct *context_isec =
2980 			selinux_inode(context_inode);
2981 		if (context_isec->initialized != LABEL_INITIALIZED) {
2982 			pr_err("SELinux:  context_inode is not initialized\n");
2983 			return -EACCES;
2984 		}
2985 
2986 		isec->sclass = context_isec->sclass;
2987 		isec->sid = context_isec->sid;
2988 	} else {
2989 		isec->sclass = SECCLASS_ANON_INODE;
2990 		rc = security_transition_sid(
2991 			sid, sid,
2992 			isec->sclass, name, &isec->sid);
2993 		if (rc)
2994 			return rc;
2995 	}
2996 
2997 	isec->initialized = LABEL_INITIALIZED;
2998 	/*
2999 	 * Now that we've initialized security, check whether we're
3000 	 * allowed to actually create this type of anonymous inode.
3001 	 */
3002 
3003 	ad.type = LSM_AUDIT_DATA_ANONINODE;
3004 	ad.u.anonclass = name ? (const char *)name->name : "?";
3005 
3006 	return avc_has_perm(sid,
3007 			    isec->sid,
3008 			    isec->sclass,
3009 			    FILE__CREATE,
3010 			    &ad);
3011 }
3012 
selinux_inode_create(struct inode * dir,struct dentry * dentry,umode_t mode)3013 static int selinux_inode_create(struct inode *dir, struct dentry *dentry, umode_t mode)
3014 {
3015 	return may_create(dir, dentry, SECCLASS_FILE);
3016 }
3017 
selinux_inode_link(struct dentry * old_dentry,struct inode * dir,struct dentry * new_dentry)3018 static int selinux_inode_link(struct dentry *old_dentry, struct inode *dir, struct dentry *new_dentry)
3019 {
3020 	return may_link(dir, old_dentry, MAY_LINK);
3021 }
3022 
selinux_inode_unlink(struct inode * dir,struct dentry * dentry)3023 static int selinux_inode_unlink(struct inode *dir, struct dentry *dentry)
3024 {
3025 	return may_link(dir, dentry, MAY_UNLINK);
3026 }
3027 
selinux_inode_symlink(struct inode * dir,struct dentry * dentry,const char * name)3028 static int selinux_inode_symlink(struct inode *dir, struct dentry *dentry, const char *name)
3029 {
3030 	return may_create(dir, dentry, SECCLASS_LNK_FILE);
3031 }
3032 
selinux_inode_mkdir(struct inode * dir,struct dentry * dentry,umode_t mask)3033 static int selinux_inode_mkdir(struct inode *dir, struct dentry *dentry, umode_t mask)
3034 {
3035 	return may_create(dir, dentry, SECCLASS_DIR);
3036 }
3037 
selinux_inode_rmdir(struct inode * dir,struct dentry * dentry)3038 static int selinux_inode_rmdir(struct inode *dir, struct dentry *dentry)
3039 {
3040 	return may_link(dir, dentry, MAY_RMDIR);
3041 }
3042 
selinux_inode_mknod(struct inode * dir,struct dentry * dentry,umode_t mode,dev_t dev)3043 static int selinux_inode_mknod(struct inode *dir, struct dentry *dentry, umode_t mode, dev_t dev)
3044 {
3045 	return may_create(dir, dentry, inode_mode_to_security_class(mode));
3046 }
3047 
selinux_inode_rename(struct inode * old_inode,struct dentry * old_dentry,struct inode * new_inode,struct dentry * new_dentry)3048 static int selinux_inode_rename(struct inode *old_inode, struct dentry *old_dentry,
3049 				struct inode *new_inode, struct dentry *new_dentry)
3050 {
3051 	return may_rename(old_inode, old_dentry, new_inode, new_dentry);
3052 }
3053 
selinux_inode_readlink(struct dentry * dentry)3054 static int selinux_inode_readlink(struct dentry *dentry)
3055 {
3056 	const struct cred *cred = current_cred();
3057 
3058 	return dentry_has_perm(cred, dentry, FILE__READ);
3059 }
3060 
selinux_inode_follow_link(struct dentry * dentry,struct inode * inode,bool rcu)3061 static int selinux_inode_follow_link(struct dentry *dentry, struct inode *inode,
3062 				     bool rcu)
3063 {
3064 	struct common_audit_data ad;
3065 	struct inode_security_struct *isec;
3066 	u32 sid = current_sid();
3067 
3068 	ad.type = LSM_AUDIT_DATA_DENTRY;
3069 	ad.u.dentry = dentry;
3070 	isec = inode_security_rcu(inode, rcu);
3071 	if (IS_ERR(isec))
3072 		return PTR_ERR(isec);
3073 
3074 	return avc_has_perm(sid, isec->sid, isec->sclass, FILE__READ, &ad);
3075 }
3076 
audit_inode_permission(struct inode * inode,u32 perms,u32 audited,u32 denied,int result)3077 static noinline int audit_inode_permission(struct inode *inode,
3078 					   u32 perms, u32 audited, u32 denied,
3079 					   int result)
3080 {
3081 	struct common_audit_data ad;
3082 	struct inode_security_struct *isec = selinux_inode(inode);
3083 
3084 	ad.type = LSM_AUDIT_DATA_INODE;
3085 	ad.u.inode = inode;
3086 
3087 	return slow_avc_audit(current_sid(), isec->sid, isec->sclass, perms,
3088 			    audited, denied, result, &ad);
3089 }
3090 
selinux_inode_permission(struct inode * inode,int mask)3091 static int selinux_inode_permission(struct inode *inode, int mask)
3092 {
3093 	u32 perms;
3094 	bool from_access;
3095 	bool no_block = mask & MAY_NOT_BLOCK;
3096 	struct inode_security_struct *isec;
3097 	u32 sid = current_sid();
3098 	struct av_decision avd;
3099 	int rc, rc2;
3100 	u32 audited, denied;
3101 
3102 	from_access = mask & MAY_ACCESS;
3103 	mask &= (MAY_READ|MAY_WRITE|MAY_EXEC|MAY_APPEND);
3104 
3105 	/* No permission to check.  Existence test. */
3106 	if (!mask)
3107 		return 0;
3108 
3109 	if (unlikely(IS_PRIVATE(inode)))
3110 		return 0;
3111 
3112 	perms = file_mask_to_av(inode->i_mode, mask);
3113 
3114 	isec = inode_security_rcu(inode, no_block);
3115 	if (IS_ERR(isec))
3116 		return PTR_ERR(isec);
3117 
3118 	rc = avc_has_perm_noaudit(sid, isec->sid, isec->sclass, perms, 0,
3119 				  &avd);
3120 	audited = avc_audit_required(perms, &avd, rc,
3121 				     from_access ? FILE__AUDIT_ACCESS : 0,
3122 				     &denied);
3123 	if (likely(!audited))
3124 		return rc;
3125 
3126 	rc2 = audit_inode_permission(inode, perms, audited, denied, rc);
3127 	if (rc2)
3128 		return rc2;
3129 	return rc;
3130 }
3131 
selinux_inode_setattr(struct mnt_idmap * idmap,struct dentry * dentry,struct iattr * iattr)3132 static int selinux_inode_setattr(struct mnt_idmap *idmap, struct dentry *dentry,
3133 				 struct iattr *iattr)
3134 {
3135 	const struct cred *cred = current_cred();
3136 	struct inode *inode = d_backing_inode(dentry);
3137 	unsigned int ia_valid = iattr->ia_valid;
3138 	u32 av = FILE__WRITE;
3139 
3140 	/* ATTR_FORCE is just used for ATTR_KILL_S[UG]ID. */
3141 	if (ia_valid & ATTR_FORCE) {
3142 		ia_valid &= ~(ATTR_KILL_SUID | ATTR_KILL_SGID | ATTR_MODE |
3143 			      ATTR_FORCE);
3144 		if (!ia_valid)
3145 			return 0;
3146 	}
3147 
3148 	if (ia_valid & (ATTR_MODE | ATTR_UID | ATTR_GID |
3149 			ATTR_ATIME_SET | ATTR_MTIME_SET | ATTR_TIMES_SET))
3150 		return dentry_has_perm(cred, dentry, FILE__SETATTR);
3151 
3152 	if (selinux_policycap_openperm() &&
3153 	    inode->i_sb->s_magic != SOCKFS_MAGIC &&
3154 	    (ia_valid & ATTR_SIZE) &&
3155 	    !(ia_valid & ATTR_FILE))
3156 		av |= FILE__OPEN;
3157 
3158 	return dentry_has_perm(cred, dentry, av);
3159 }
3160 
selinux_inode_getattr(const struct path * path)3161 static int selinux_inode_getattr(const struct path *path)
3162 {
3163 	return path_has_perm(current_cred(), path, FILE__GETATTR);
3164 }
3165 
has_cap_mac_admin(bool audit)3166 static bool has_cap_mac_admin(bool audit)
3167 {
3168 	const struct cred *cred = current_cred();
3169 	unsigned int opts = audit ? CAP_OPT_NONE : CAP_OPT_NOAUDIT;
3170 
3171 	if (cap_capable(cred, &init_user_ns, CAP_MAC_ADMIN, opts))
3172 		return false;
3173 	if (cred_has_capability(cred, CAP_MAC_ADMIN, opts, true))
3174 		return false;
3175 	return true;
3176 }
3177 
3178 /**
3179  * selinux_inode_xattr_skipcap - Skip the xattr capability checks?
3180  * @name: name of the xattr
3181  *
3182  * Returns 1 to indicate that SELinux "owns" the access control rights to xattrs
3183  * named @name; the LSM layer should avoid enforcing any traditional
3184  * capability based access controls on this xattr.  Returns 0 to indicate that
3185  * SELinux does not "own" the access control rights to xattrs named @name and is
3186  * deferring to the LSM layer for further access controls, including capability
3187  * based controls.
3188  */
selinux_inode_xattr_skipcap(const char * name)3189 static int selinux_inode_xattr_skipcap(const char *name)
3190 {
3191 	/* require capability check if not a selinux xattr */
3192 	return !strcmp(name, XATTR_NAME_SELINUX);
3193 }
3194 
selinux_inode_setxattr(struct mnt_idmap * idmap,struct dentry * dentry,const char * name,const void * value,size_t size,int flags)3195 static int selinux_inode_setxattr(struct mnt_idmap *idmap,
3196 				  struct dentry *dentry, const char *name,
3197 				  const void *value, size_t size, int flags)
3198 {
3199 	struct inode *inode = d_backing_inode(dentry);
3200 	struct inode_security_struct *isec;
3201 	struct superblock_security_struct *sbsec;
3202 	struct common_audit_data ad;
3203 	u32 newsid, sid = current_sid();
3204 	int rc = 0;
3205 
3206 	/* if not a selinux xattr, only check the ordinary setattr perm */
3207 	if (strcmp(name, XATTR_NAME_SELINUX))
3208 		return dentry_has_perm(current_cred(), dentry, FILE__SETATTR);
3209 
3210 	if (!selinux_initialized())
3211 		return (inode_owner_or_capable(idmap, inode) ? 0 : -EPERM);
3212 
3213 	sbsec = selinux_superblock(inode->i_sb);
3214 	if (!(sbsec->flags & SBLABEL_MNT))
3215 		return -EOPNOTSUPP;
3216 
3217 	if (!inode_owner_or_capable(idmap, inode))
3218 		return -EPERM;
3219 
3220 	ad.type = LSM_AUDIT_DATA_DENTRY;
3221 	ad.u.dentry = dentry;
3222 
3223 	isec = backing_inode_security(dentry);
3224 	rc = avc_has_perm(sid, isec->sid, isec->sclass,
3225 			  FILE__RELABELFROM, &ad);
3226 	if (rc)
3227 		return rc;
3228 
3229 	rc = security_context_to_sid(value, size, &newsid,
3230 				     GFP_KERNEL);
3231 	if (rc == -EINVAL) {
3232 		if (!has_cap_mac_admin(true)) {
3233 			struct audit_buffer *ab;
3234 			size_t audit_size;
3235 
3236 			/* We strip a nul only if it is at the end, otherwise the
3237 			 * context contains a nul and we should audit that */
3238 			if (value) {
3239 				const char *str = value;
3240 
3241 				if (str[size - 1] == '\0')
3242 					audit_size = size - 1;
3243 				else
3244 					audit_size = size;
3245 			} else {
3246 				audit_size = 0;
3247 			}
3248 			ab = audit_log_start(audit_context(),
3249 					     GFP_ATOMIC, AUDIT_SELINUX_ERR);
3250 			if (!ab)
3251 				return rc;
3252 			audit_log_format(ab, "op=setxattr invalid_context=");
3253 			audit_log_n_untrustedstring(ab, value, audit_size);
3254 			audit_log_end(ab);
3255 
3256 			return rc;
3257 		}
3258 		rc = security_context_to_sid_force(value,
3259 						   size, &newsid);
3260 	}
3261 	if (rc)
3262 		return rc;
3263 
3264 	rc = avc_has_perm(sid, newsid, isec->sclass,
3265 			  FILE__RELABELTO, &ad);
3266 	if (rc)
3267 		return rc;
3268 
3269 	rc = security_validate_transition(isec->sid, newsid,
3270 					  sid, isec->sclass);
3271 	if (rc)
3272 		return rc;
3273 
3274 	return avc_has_perm(newsid,
3275 			    sbsec->sid,
3276 			    SECCLASS_FILESYSTEM,
3277 			    FILESYSTEM__ASSOCIATE,
3278 			    &ad);
3279 }
3280 
selinux_inode_set_acl(struct mnt_idmap * idmap,struct dentry * dentry,const char * acl_name,struct posix_acl * kacl)3281 static int selinux_inode_set_acl(struct mnt_idmap *idmap,
3282 				 struct dentry *dentry, const char *acl_name,
3283 				 struct posix_acl *kacl)
3284 {
3285 	return dentry_has_perm(current_cred(), dentry, FILE__SETATTR);
3286 }
3287 
selinux_inode_get_acl(struct mnt_idmap * idmap,struct dentry * dentry,const char * acl_name)3288 static int selinux_inode_get_acl(struct mnt_idmap *idmap,
3289 				 struct dentry *dentry, const char *acl_name)
3290 {
3291 	return dentry_has_perm(current_cred(), dentry, FILE__GETATTR);
3292 }
3293 
selinux_inode_remove_acl(struct mnt_idmap * idmap,struct dentry * dentry,const char * acl_name)3294 static int selinux_inode_remove_acl(struct mnt_idmap *idmap,
3295 				    struct dentry *dentry, const char *acl_name)
3296 {
3297 	return dentry_has_perm(current_cred(), dentry, FILE__SETATTR);
3298 }
3299 
selinux_inode_post_setxattr(struct dentry * dentry,const char * name,const void * value,size_t size,int flags)3300 static void selinux_inode_post_setxattr(struct dentry *dentry, const char *name,
3301 					const void *value, size_t size,
3302 					int flags)
3303 {
3304 	struct inode *inode = d_backing_inode(dentry);
3305 	struct inode_security_struct *isec;
3306 	u32 newsid;
3307 	int rc;
3308 
3309 	if (strcmp(name, XATTR_NAME_SELINUX)) {
3310 		/* Not an attribute we recognize, so nothing to do. */
3311 		return;
3312 	}
3313 
3314 	if (!selinux_initialized()) {
3315 		/* If we haven't even been initialized, then we can't validate
3316 		 * against a policy, so leave the label as invalid. It may
3317 		 * resolve to a valid label on the next revalidation try if
3318 		 * we've since initialized.
3319 		 */
3320 		return;
3321 	}
3322 
3323 	rc = security_context_to_sid_force(value, size,
3324 					   &newsid);
3325 	if (rc) {
3326 		pr_err("SELinux:  unable to map context to SID"
3327 		       "for (%s, %lu), rc=%d\n",
3328 		       inode->i_sb->s_id, inode->i_ino, -rc);
3329 		return;
3330 	}
3331 
3332 	isec = backing_inode_security(dentry);
3333 	spin_lock(&isec->lock);
3334 	isec->sclass = inode_mode_to_security_class(inode->i_mode);
3335 	isec->sid = newsid;
3336 	isec->initialized = LABEL_INITIALIZED;
3337 	spin_unlock(&isec->lock);
3338 }
3339 
selinux_inode_getxattr(struct dentry * dentry,const char * name)3340 static int selinux_inode_getxattr(struct dentry *dentry, const char *name)
3341 {
3342 	const struct cred *cred = current_cred();
3343 
3344 	return dentry_has_perm(cred, dentry, FILE__GETATTR);
3345 }
3346 
selinux_inode_listxattr(struct dentry * dentry)3347 static int selinux_inode_listxattr(struct dentry *dentry)
3348 {
3349 	const struct cred *cred = current_cred();
3350 
3351 	return dentry_has_perm(cred, dentry, FILE__GETATTR);
3352 }
3353 
selinux_inode_removexattr(struct mnt_idmap * idmap,struct dentry * dentry,const char * name)3354 static int selinux_inode_removexattr(struct mnt_idmap *idmap,
3355 				     struct dentry *dentry, const char *name)
3356 {
3357 	/* if not a selinux xattr, only check the ordinary setattr perm */
3358 	if (strcmp(name, XATTR_NAME_SELINUX))
3359 		return dentry_has_perm(current_cred(), dentry, FILE__SETATTR);
3360 
3361 	if (!selinux_initialized())
3362 		return 0;
3363 
3364 	/* No one is allowed to remove a SELinux security label.
3365 	   You can change the label, but all data must be labeled. */
3366 	return -EACCES;
3367 }
3368 
selinux_path_notify(const struct path * path,u64 mask,unsigned int obj_type)3369 static int selinux_path_notify(const struct path *path, u64 mask,
3370 						unsigned int obj_type)
3371 {
3372 	int ret;
3373 	u32 perm;
3374 
3375 	struct common_audit_data ad;
3376 
3377 	ad.type = LSM_AUDIT_DATA_PATH;
3378 	ad.u.path = *path;
3379 
3380 	/*
3381 	 * Set permission needed based on the type of mark being set.
3382 	 * Performs an additional check for sb watches.
3383 	 */
3384 	switch (obj_type) {
3385 	case FSNOTIFY_OBJ_TYPE_VFSMOUNT:
3386 		perm = FILE__WATCH_MOUNT;
3387 		break;
3388 	case FSNOTIFY_OBJ_TYPE_SB:
3389 		perm = FILE__WATCH_SB;
3390 		ret = superblock_has_perm(current_cred(), path->dentry->d_sb,
3391 						FILESYSTEM__WATCH, &ad);
3392 		if (ret)
3393 			return ret;
3394 		break;
3395 	case FSNOTIFY_OBJ_TYPE_INODE:
3396 		perm = FILE__WATCH;
3397 		break;
3398 	case FSNOTIFY_OBJ_TYPE_MNTNS:
3399 		perm = FILE__WATCH_MOUNTNS;
3400 		break;
3401 	default:
3402 		return -EINVAL;
3403 	}
3404 
3405 	/* blocking watches require the file:watch_with_perm permission */
3406 	if (mask & (ALL_FSNOTIFY_PERM_EVENTS))
3407 		perm |= FILE__WATCH_WITH_PERM;
3408 
3409 	/* watches on read-like events need the file:watch_reads permission */
3410 	if (mask & (FS_ACCESS | FS_ACCESS_PERM | FS_PRE_ACCESS |
3411 		    FS_CLOSE_NOWRITE))
3412 		perm |= FILE__WATCH_READS;
3413 
3414 	return path_has_perm(current_cred(), path, perm);
3415 }
3416 
3417 /*
3418  * Copy the inode security context value to the user.
3419  *
3420  * Permission check is handled by selinux_inode_getxattr hook.
3421  */
selinux_inode_getsecurity(struct mnt_idmap * idmap,struct inode * inode,const char * name,void ** buffer,bool alloc)3422 static int selinux_inode_getsecurity(struct mnt_idmap *idmap,
3423 				     struct inode *inode, const char *name,
3424 				     void **buffer, bool alloc)
3425 {
3426 	u32 size;
3427 	int error;
3428 	char *context = NULL;
3429 	struct inode_security_struct *isec;
3430 
3431 	/*
3432 	 * If we're not initialized yet, then we can't validate contexts, so
3433 	 * just let vfs_getxattr fall back to using the on-disk xattr.
3434 	 */
3435 	if (!selinux_initialized() ||
3436 	    strcmp(name, XATTR_SELINUX_SUFFIX))
3437 		return -EOPNOTSUPP;
3438 
3439 	/*
3440 	 * If the caller has CAP_MAC_ADMIN, then get the raw context
3441 	 * value even if it is not defined by current policy; otherwise,
3442 	 * use the in-core value under current policy.
3443 	 * Use the non-auditing forms of the permission checks since
3444 	 * getxattr may be called by unprivileged processes commonly
3445 	 * and lack of permission just means that we fall back to the
3446 	 * in-core context value, not a denial.
3447 	 */
3448 	isec = inode_security(inode);
3449 	if (has_cap_mac_admin(false))
3450 		error = security_sid_to_context_force(isec->sid, &context,
3451 						      &size);
3452 	else
3453 		error = security_sid_to_context(isec->sid,
3454 						&context, &size);
3455 	if (error)
3456 		return error;
3457 	error = size;
3458 	if (alloc) {
3459 		*buffer = context;
3460 		goto out_nofree;
3461 	}
3462 	kfree(context);
3463 out_nofree:
3464 	return error;
3465 }
3466 
selinux_inode_setsecurity(struct inode * inode,const char * name,const void * value,size_t size,int flags)3467 static int selinux_inode_setsecurity(struct inode *inode, const char *name,
3468 				     const void *value, size_t size, int flags)
3469 {
3470 	struct inode_security_struct *isec = inode_security_novalidate(inode);
3471 	struct superblock_security_struct *sbsec;
3472 	u32 newsid;
3473 	int rc;
3474 
3475 	if (strcmp(name, XATTR_SELINUX_SUFFIX))
3476 		return -EOPNOTSUPP;
3477 
3478 	sbsec = selinux_superblock(inode->i_sb);
3479 	if (!(sbsec->flags & SBLABEL_MNT))
3480 		return -EOPNOTSUPP;
3481 
3482 	if (!value || !size)
3483 		return -EACCES;
3484 
3485 	rc = security_context_to_sid(value, size, &newsid,
3486 				     GFP_KERNEL);
3487 	if (rc)
3488 		return rc;
3489 
3490 	spin_lock(&isec->lock);
3491 	isec->sclass = inode_mode_to_security_class(inode->i_mode);
3492 	isec->sid = newsid;
3493 	isec->initialized = LABEL_INITIALIZED;
3494 	spin_unlock(&isec->lock);
3495 	return 0;
3496 }
3497 
selinux_inode_listsecurity(struct inode * inode,char * buffer,size_t buffer_size)3498 static int selinux_inode_listsecurity(struct inode *inode, char *buffer, size_t buffer_size)
3499 {
3500 	const int len = sizeof(XATTR_NAME_SELINUX);
3501 
3502 	if (!selinux_initialized())
3503 		return 0;
3504 
3505 	if (buffer && len <= buffer_size)
3506 		memcpy(buffer, XATTR_NAME_SELINUX, len);
3507 	return len;
3508 }
3509 
selinux_inode_getlsmprop(struct inode * inode,struct lsm_prop * prop)3510 static void selinux_inode_getlsmprop(struct inode *inode, struct lsm_prop *prop)
3511 {
3512 	struct inode_security_struct *isec = inode_security_novalidate(inode);
3513 
3514 	prop->selinux.secid = isec->sid;
3515 }
3516 
selinux_inode_copy_up(struct dentry * src,struct cred ** new)3517 static int selinux_inode_copy_up(struct dentry *src, struct cred **new)
3518 {
3519 	struct lsm_prop prop;
3520 	struct task_security_struct *tsec;
3521 	struct cred *new_creds = *new;
3522 
3523 	if (new_creds == NULL) {
3524 		new_creds = prepare_creds();
3525 		if (!new_creds)
3526 			return -ENOMEM;
3527 	}
3528 
3529 	tsec = selinux_cred(new_creds);
3530 	/* Get label from overlay inode and set it in create_sid */
3531 	selinux_inode_getlsmprop(d_inode(src), &prop);
3532 	tsec->create_sid = prop.selinux.secid;
3533 	*new = new_creds;
3534 	return 0;
3535 }
3536 
selinux_inode_copy_up_xattr(struct dentry * dentry,const char * name)3537 static int selinux_inode_copy_up_xattr(struct dentry *dentry, const char *name)
3538 {
3539 	/* The copy_up hook above sets the initial context on an inode, but we
3540 	 * don't then want to overwrite it by blindly copying all the lower
3541 	 * xattrs up.  Instead, filter out SELinux-related xattrs following
3542 	 * policy load.
3543 	 */
3544 	if (selinux_initialized() && !strcmp(name, XATTR_NAME_SELINUX))
3545 		return -ECANCELED; /* Discard */
3546 	/*
3547 	 * Any other attribute apart from SELINUX is not claimed, supported
3548 	 * by selinux.
3549 	 */
3550 	return -EOPNOTSUPP;
3551 }
3552 
3553 /* kernfs node operations */
3554 
selinux_kernfs_init_security(struct kernfs_node * kn_dir,struct kernfs_node * kn)3555 static int selinux_kernfs_init_security(struct kernfs_node *kn_dir,
3556 					struct kernfs_node *kn)
3557 {
3558 	const struct task_security_struct *tsec = selinux_cred(current_cred());
3559 	u32 parent_sid, newsid, clen;
3560 	int rc;
3561 	char *context;
3562 
3563 	rc = kernfs_xattr_get(kn_dir, XATTR_NAME_SELINUX, NULL, 0);
3564 	if (rc == -ENODATA)
3565 		return 0;
3566 	else if (rc < 0)
3567 		return rc;
3568 
3569 	clen = (u32)rc;
3570 	context = kmalloc(clen, GFP_KERNEL);
3571 	if (!context)
3572 		return -ENOMEM;
3573 
3574 	rc = kernfs_xattr_get(kn_dir, XATTR_NAME_SELINUX, context, clen);
3575 	if (rc < 0) {
3576 		kfree(context);
3577 		return rc;
3578 	}
3579 
3580 	rc = security_context_to_sid(context, clen, &parent_sid,
3581 				     GFP_KERNEL);
3582 	kfree(context);
3583 	if (rc)
3584 		return rc;
3585 
3586 	if (tsec->create_sid) {
3587 		newsid = tsec->create_sid;
3588 	} else {
3589 		u16 secclass = inode_mode_to_security_class(kn->mode);
3590 		const char *kn_name;
3591 		struct qstr q;
3592 
3593 		/* kn is fresh, can't be renamed, name goes not away */
3594 		kn_name = rcu_dereference_check(kn->name, true);
3595 		q.name = kn_name;
3596 		q.hash_len = hashlen_string(kn_dir, kn_name);
3597 
3598 		rc = security_transition_sid(tsec->sid,
3599 					     parent_sid, secclass, &q,
3600 					     &newsid);
3601 		if (rc)
3602 			return rc;
3603 	}
3604 
3605 	rc = security_sid_to_context_force(newsid,
3606 					   &context, &clen);
3607 	if (rc)
3608 		return rc;
3609 
3610 	rc = kernfs_xattr_set(kn, XATTR_NAME_SELINUX, context, clen,
3611 			      XATTR_CREATE);
3612 	kfree(context);
3613 	return rc;
3614 }
3615 
3616 
3617 /* file security operations */
3618 
selinux_revalidate_file_permission(struct file * file,int mask)3619 static int selinux_revalidate_file_permission(struct file *file, int mask)
3620 {
3621 	const struct cred *cred = current_cred();
3622 	struct inode *inode = file_inode(file);
3623 
3624 	/* file_mask_to_av won't add FILE__WRITE if MAY_APPEND is set */
3625 	if ((file->f_flags & O_APPEND) && (mask & MAY_WRITE))
3626 		mask |= MAY_APPEND;
3627 
3628 	return file_has_perm(cred, file,
3629 			     file_mask_to_av(inode->i_mode, mask));
3630 }
3631 
selinux_file_permission(struct file * file,int mask)3632 static int selinux_file_permission(struct file *file, int mask)
3633 {
3634 	struct inode *inode = file_inode(file);
3635 	struct file_security_struct *fsec = selinux_file(file);
3636 	struct inode_security_struct *isec;
3637 	u32 sid = current_sid();
3638 
3639 	if (!mask)
3640 		/* No permission to check.  Existence test. */
3641 		return 0;
3642 
3643 	isec = inode_security(inode);
3644 	if (sid == fsec->sid && fsec->isid == isec->sid &&
3645 	    fsec->pseqno == avc_policy_seqno())
3646 		/* No change since file_open check. */
3647 		return 0;
3648 
3649 	return selinux_revalidate_file_permission(file, mask);
3650 }
3651 
selinux_file_alloc_security(struct file * file)3652 static int selinux_file_alloc_security(struct file *file)
3653 {
3654 	struct file_security_struct *fsec = selinux_file(file);
3655 	u32 sid = current_sid();
3656 
3657 	fsec->sid = sid;
3658 	fsec->fown_sid = sid;
3659 
3660 	return 0;
3661 }
3662 
3663 /*
3664  * Check whether a task has the ioctl permission and cmd
3665  * operation to an inode.
3666  */
ioctl_has_perm(const struct cred * cred,struct file * file,u32 requested,u16 cmd)3667 static int ioctl_has_perm(const struct cred *cred, struct file *file,
3668 		u32 requested, u16 cmd)
3669 {
3670 	struct common_audit_data ad;
3671 	struct file_security_struct *fsec = selinux_file(file);
3672 	struct inode *inode = file_inode(file);
3673 	struct inode_security_struct *isec;
3674 	struct lsm_ioctlop_audit ioctl;
3675 	u32 ssid = cred_sid(cred);
3676 	int rc;
3677 	u8 driver = cmd >> 8;
3678 	u8 xperm = cmd & 0xff;
3679 
3680 	ad.type = LSM_AUDIT_DATA_IOCTL_OP;
3681 	ad.u.op = &ioctl;
3682 	ad.u.op->cmd = cmd;
3683 	ad.u.op->path = file->f_path;
3684 
3685 	if (ssid != fsec->sid) {
3686 		rc = avc_has_perm(ssid, fsec->sid,
3687 				SECCLASS_FD,
3688 				FD__USE,
3689 				&ad);
3690 		if (rc)
3691 			goto out;
3692 	}
3693 
3694 	if (unlikely(IS_PRIVATE(inode)))
3695 		return 0;
3696 
3697 	isec = inode_security(inode);
3698 	rc = avc_has_extended_perms(ssid, isec->sid, isec->sclass, requested,
3699 				    driver, AVC_EXT_IOCTL, xperm, &ad);
3700 out:
3701 	return rc;
3702 }
3703 
selinux_file_ioctl(struct file * file,unsigned int cmd,unsigned long arg)3704 static int selinux_file_ioctl(struct file *file, unsigned int cmd,
3705 			      unsigned long arg)
3706 {
3707 	const struct cred *cred = current_cred();
3708 	int error = 0;
3709 
3710 	switch (cmd) {
3711 	case FIONREAD:
3712 	case FIBMAP:
3713 	case FIGETBSZ:
3714 	case FS_IOC_GETFLAGS:
3715 	case FS_IOC_GETVERSION:
3716 		error = file_has_perm(cred, file, FILE__GETATTR);
3717 		break;
3718 
3719 	case FS_IOC_SETFLAGS:
3720 	case FS_IOC_SETVERSION:
3721 		error = file_has_perm(cred, file, FILE__SETATTR);
3722 		break;
3723 
3724 	/* sys_ioctl() checks */
3725 	case FIONBIO:
3726 	case FIOASYNC:
3727 		error = file_has_perm(cred, file, 0);
3728 		break;
3729 
3730 	case KDSKBENT:
3731 	case KDSKBSENT:
3732 		error = cred_has_capability(cred, CAP_SYS_TTY_CONFIG,
3733 					    CAP_OPT_NONE, true);
3734 		break;
3735 
3736 	case FIOCLEX:
3737 	case FIONCLEX:
3738 		if (!selinux_policycap_ioctl_skip_cloexec())
3739 			error = ioctl_has_perm(cred, file, FILE__IOCTL, (u16) cmd);
3740 		break;
3741 
3742 	/* default case assumes that the command will go
3743 	 * to the file's ioctl() function.
3744 	 */
3745 	default:
3746 		error = ioctl_has_perm(cred, file, FILE__IOCTL, (u16) cmd);
3747 	}
3748 	return error;
3749 }
3750 
selinux_file_ioctl_compat(struct file * file,unsigned int cmd,unsigned long arg)3751 static int selinux_file_ioctl_compat(struct file *file, unsigned int cmd,
3752 			      unsigned long arg)
3753 {
3754 	/*
3755 	 * If we are in a 64-bit kernel running 32-bit userspace, we need to
3756 	 * make sure we don't compare 32-bit flags to 64-bit flags.
3757 	 */
3758 	switch (cmd) {
3759 	case FS_IOC32_GETFLAGS:
3760 		cmd = FS_IOC_GETFLAGS;
3761 		break;
3762 	case FS_IOC32_SETFLAGS:
3763 		cmd = FS_IOC_SETFLAGS;
3764 		break;
3765 	case FS_IOC32_GETVERSION:
3766 		cmd = FS_IOC_GETVERSION;
3767 		break;
3768 	case FS_IOC32_SETVERSION:
3769 		cmd = FS_IOC_SETVERSION;
3770 		break;
3771 	default:
3772 		break;
3773 	}
3774 
3775 	return selinux_file_ioctl(file, cmd, arg);
3776 }
3777 
3778 static int default_noexec __ro_after_init;
3779 
file_map_prot_check(struct file * file,unsigned long prot,int shared)3780 static int file_map_prot_check(struct file *file, unsigned long prot, int shared)
3781 {
3782 	const struct cred *cred = current_cred();
3783 	u32 sid = cred_sid(cred);
3784 	int rc = 0;
3785 
3786 	if (default_noexec &&
3787 	    (prot & PROT_EXEC) && (!file || IS_PRIVATE(file_inode(file)) ||
3788 				   (!shared && (prot & PROT_WRITE)))) {
3789 		/*
3790 		 * We are making executable an anonymous mapping or a
3791 		 * private file mapping that will also be writable.
3792 		 * This has an additional check.
3793 		 */
3794 		rc = avc_has_perm(sid, sid, SECCLASS_PROCESS,
3795 				  PROCESS__EXECMEM, NULL);
3796 		if (rc)
3797 			goto error;
3798 	}
3799 
3800 	if (file) {
3801 		/* read access is always possible with a mapping */
3802 		u32 av = FILE__READ;
3803 
3804 		/* write access only matters if the mapping is shared */
3805 		if (shared && (prot & PROT_WRITE))
3806 			av |= FILE__WRITE;
3807 
3808 		if (prot & PROT_EXEC)
3809 			av |= FILE__EXECUTE;
3810 
3811 		return file_has_perm(cred, file, av);
3812 	}
3813 
3814 error:
3815 	return rc;
3816 }
3817 
selinux_mmap_addr(unsigned long addr)3818 static int selinux_mmap_addr(unsigned long addr)
3819 {
3820 	int rc = 0;
3821 
3822 	if (addr < CONFIG_LSM_MMAP_MIN_ADDR) {
3823 		u32 sid = current_sid();
3824 		rc = avc_has_perm(sid, sid, SECCLASS_MEMPROTECT,
3825 				  MEMPROTECT__MMAP_ZERO, NULL);
3826 	}
3827 
3828 	return rc;
3829 }
3830 
selinux_mmap_file(struct file * file,unsigned long reqprot __always_unused,unsigned long prot,unsigned long flags)3831 static int selinux_mmap_file(struct file *file,
3832 			     unsigned long reqprot __always_unused,
3833 			     unsigned long prot, unsigned long flags)
3834 {
3835 	struct common_audit_data ad;
3836 	int rc;
3837 
3838 	if (file) {
3839 		ad.type = LSM_AUDIT_DATA_FILE;
3840 		ad.u.file = file;
3841 		rc = inode_has_perm(current_cred(), file_inode(file),
3842 				    FILE__MAP, &ad);
3843 		if (rc)
3844 			return rc;
3845 	}
3846 
3847 	return file_map_prot_check(file, prot,
3848 				   (flags & MAP_TYPE) == MAP_SHARED);
3849 }
3850 
selinux_file_mprotect(struct vm_area_struct * vma,unsigned long reqprot __always_unused,unsigned long prot)3851 static int selinux_file_mprotect(struct vm_area_struct *vma,
3852 				 unsigned long reqprot __always_unused,
3853 				 unsigned long prot)
3854 {
3855 	const struct cred *cred = current_cred();
3856 	u32 sid = cred_sid(cred);
3857 
3858 	if (default_noexec &&
3859 	    (prot & PROT_EXEC) && !(vma->vm_flags & VM_EXEC)) {
3860 		int rc = 0;
3861 		/*
3862 		 * We don't use the vma_is_initial_heap() helper as it has
3863 		 * a history of problems and is currently broken on systems
3864 		 * where there is no heap, e.g. brk == start_brk.  Before
3865 		 * replacing the conditional below with vma_is_initial_heap(),
3866 		 * or something similar, please ensure that the logic is the
3867 		 * same as what we have below or you have tested every possible
3868 		 * corner case you can think to test.
3869 		 */
3870 		if (vma->vm_start >= vma->vm_mm->start_brk &&
3871 		    vma->vm_end <= vma->vm_mm->brk) {
3872 			rc = avc_has_perm(sid, sid, SECCLASS_PROCESS,
3873 					  PROCESS__EXECHEAP, NULL);
3874 		} else if (!vma->vm_file && (vma_is_initial_stack(vma) ||
3875 			    vma_is_stack_for_current(vma))) {
3876 			rc = avc_has_perm(sid, sid, SECCLASS_PROCESS,
3877 					  PROCESS__EXECSTACK, NULL);
3878 		} else if (vma->vm_file && vma->anon_vma) {
3879 			/*
3880 			 * We are making executable a file mapping that has
3881 			 * had some COW done. Since pages might have been
3882 			 * written, check ability to execute the possibly
3883 			 * modified content.  This typically should only
3884 			 * occur for text relocations.
3885 			 */
3886 			rc = file_has_perm(cred, vma->vm_file, FILE__EXECMOD);
3887 		}
3888 		if (rc)
3889 			return rc;
3890 	}
3891 
3892 	return file_map_prot_check(vma->vm_file, prot, vma->vm_flags&VM_SHARED);
3893 }
3894 
selinux_file_lock(struct file * file,unsigned int cmd)3895 static int selinux_file_lock(struct file *file, unsigned int cmd)
3896 {
3897 	const struct cred *cred = current_cred();
3898 
3899 	return file_has_perm(cred, file, FILE__LOCK);
3900 }
3901 
selinux_file_fcntl(struct file * file,unsigned int cmd,unsigned long arg)3902 static int selinux_file_fcntl(struct file *file, unsigned int cmd,
3903 			      unsigned long arg)
3904 {
3905 	const struct cred *cred = current_cred();
3906 	int err = 0;
3907 
3908 	switch (cmd) {
3909 	case F_SETFL:
3910 		if ((file->f_flags & O_APPEND) && !(arg & O_APPEND)) {
3911 			err = file_has_perm(cred, file, FILE__WRITE);
3912 			break;
3913 		}
3914 		fallthrough;
3915 	case F_SETOWN:
3916 	case F_SETSIG:
3917 	case F_GETFL:
3918 	case F_GETOWN:
3919 	case F_GETSIG:
3920 	case F_GETOWNER_UIDS:
3921 		/* Just check FD__USE permission */
3922 		err = file_has_perm(cred, file, 0);
3923 		break;
3924 	case F_GETLK:
3925 	case F_SETLK:
3926 	case F_SETLKW:
3927 	case F_OFD_GETLK:
3928 	case F_OFD_SETLK:
3929 	case F_OFD_SETLKW:
3930 #if BITS_PER_LONG == 32
3931 	case F_GETLK64:
3932 	case F_SETLK64:
3933 	case F_SETLKW64:
3934 #endif
3935 		err = file_has_perm(cred, file, FILE__LOCK);
3936 		break;
3937 	}
3938 
3939 	return err;
3940 }
3941 
selinux_file_set_fowner(struct file * file)3942 static void selinux_file_set_fowner(struct file *file)
3943 {
3944 	struct file_security_struct *fsec;
3945 
3946 	fsec = selinux_file(file);
3947 	fsec->fown_sid = current_sid();
3948 }
3949 
selinux_file_send_sigiotask(struct task_struct * tsk,struct fown_struct * fown,int signum)3950 static int selinux_file_send_sigiotask(struct task_struct *tsk,
3951 				       struct fown_struct *fown, int signum)
3952 {
3953 	struct file *file;
3954 	u32 sid = task_sid_obj(tsk);
3955 	u32 perm;
3956 	struct file_security_struct *fsec;
3957 
3958 	/* struct fown_struct is never outside the context of a struct file */
3959 	file = fown->file;
3960 
3961 	fsec = selinux_file(file);
3962 
3963 	if (!signum)
3964 		perm = signal_to_av(SIGIO); /* as per send_sigio_to_task */
3965 	else
3966 		perm = signal_to_av(signum);
3967 
3968 	return avc_has_perm(fsec->fown_sid, sid,
3969 			    SECCLASS_PROCESS, perm, NULL);
3970 }
3971 
selinux_file_receive(struct file * file)3972 static int selinux_file_receive(struct file *file)
3973 {
3974 	const struct cred *cred = current_cred();
3975 
3976 	return file_has_perm(cred, file, file_to_av(file));
3977 }
3978 
selinux_file_open(struct file * file)3979 static int selinux_file_open(struct file *file)
3980 {
3981 	struct file_security_struct *fsec;
3982 	struct inode_security_struct *isec;
3983 
3984 	fsec = selinux_file(file);
3985 	isec = inode_security(file_inode(file));
3986 	/*
3987 	 * Save inode label and policy sequence number
3988 	 * at open-time so that selinux_file_permission
3989 	 * can determine whether revalidation is necessary.
3990 	 * Task label is already saved in the file security
3991 	 * struct as its SID.
3992 	 */
3993 	fsec->isid = isec->sid;
3994 	fsec->pseqno = avc_policy_seqno();
3995 	/*
3996 	 * Since the inode label or policy seqno may have changed
3997 	 * between the selinux_inode_permission check and the saving
3998 	 * of state above, recheck that access is still permitted.
3999 	 * Otherwise, access might never be revalidated against the
4000 	 * new inode label or new policy.
4001 	 * This check is not redundant - do not remove.
4002 	 */
4003 	return file_path_has_perm(file->f_cred, file, open_file_to_av(file));
4004 }
4005 
4006 /* task security operations */
4007 
selinux_task_alloc(struct task_struct * task,unsigned long clone_flags)4008 static int selinux_task_alloc(struct task_struct *task,
4009 			      unsigned long clone_flags)
4010 {
4011 	u32 sid = current_sid();
4012 
4013 	return avc_has_perm(sid, sid, SECCLASS_PROCESS, PROCESS__FORK, NULL);
4014 }
4015 
4016 /*
4017  * prepare a new set of credentials for modification
4018  */
selinux_cred_prepare(struct cred * new,const struct cred * old,gfp_t gfp)4019 static int selinux_cred_prepare(struct cred *new, const struct cred *old,
4020 				gfp_t gfp)
4021 {
4022 	const struct task_security_struct *old_tsec = selinux_cred(old);
4023 	struct task_security_struct *tsec = selinux_cred(new);
4024 
4025 	*tsec = *old_tsec;
4026 	return 0;
4027 }
4028 
4029 /*
4030  * transfer the SELinux data to a blank set of creds
4031  */
selinux_cred_transfer(struct cred * new,const struct cred * old)4032 static void selinux_cred_transfer(struct cred *new, const struct cred *old)
4033 {
4034 	const struct task_security_struct *old_tsec = selinux_cred(old);
4035 	struct task_security_struct *tsec = selinux_cred(new);
4036 
4037 	*tsec = *old_tsec;
4038 }
4039 
selinux_cred_getsecid(const struct cred * c,u32 * secid)4040 static void selinux_cred_getsecid(const struct cred *c, u32 *secid)
4041 {
4042 	*secid = cred_sid(c);
4043 }
4044 
selinux_cred_getlsmprop(const struct cred * c,struct lsm_prop * prop)4045 static void selinux_cred_getlsmprop(const struct cred *c, struct lsm_prop *prop)
4046 {
4047 	prop->selinux.secid = cred_sid(c);
4048 }
4049 
4050 /*
4051  * set the security data for a kernel service
4052  * - all the creation contexts are set to unlabelled
4053  */
selinux_kernel_act_as(struct cred * new,u32 secid)4054 static int selinux_kernel_act_as(struct cred *new, u32 secid)
4055 {
4056 	struct task_security_struct *tsec = selinux_cred(new);
4057 	u32 sid = current_sid();
4058 	int ret;
4059 
4060 	ret = avc_has_perm(sid, secid,
4061 			   SECCLASS_KERNEL_SERVICE,
4062 			   KERNEL_SERVICE__USE_AS_OVERRIDE,
4063 			   NULL);
4064 	if (ret == 0) {
4065 		tsec->sid = secid;
4066 		tsec->create_sid = 0;
4067 		tsec->keycreate_sid = 0;
4068 		tsec->sockcreate_sid = 0;
4069 	}
4070 	return ret;
4071 }
4072 
4073 /*
4074  * set the file creation context in a security record to the same as the
4075  * objective context of the specified inode
4076  */
selinux_kernel_create_files_as(struct cred * new,struct inode * inode)4077 static int selinux_kernel_create_files_as(struct cred *new, struct inode *inode)
4078 {
4079 	struct inode_security_struct *isec = inode_security(inode);
4080 	struct task_security_struct *tsec = selinux_cred(new);
4081 	u32 sid = current_sid();
4082 	int ret;
4083 
4084 	ret = avc_has_perm(sid, isec->sid,
4085 			   SECCLASS_KERNEL_SERVICE,
4086 			   KERNEL_SERVICE__CREATE_FILES_AS,
4087 			   NULL);
4088 
4089 	if (ret == 0)
4090 		tsec->create_sid = isec->sid;
4091 	return ret;
4092 }
4093 
selinux_kernel_module_request(char * kmod_name)4094 static int selinux_kernel_module_request(char *kmod_name)
4095 {
4096 	struct common_audit_data ad;
4097 
4098 	ad.type = LSM_AUDIT_DATA_KMOD;
4099 	ad.u.kmod_name = kmod_name;
4100 
4101 	return avc_has_perm(current_sid(), SECINITSID_KERNEL, SECCLASS_SYSTEM,
4102 			    SYSTEM__MODULE_REQUEST, &ad);
4103 }
4104 
selinux_kernel_load_from_file(struct file * file,u32 requested)4105 static int selinux_kernel_load_from_file(struct file *file, u32 requested)
4106 {
4107 	struct common_audit_data ad;
4108 	struct inode_security_struct *isec;
4109 	struct file_security_struct *fsec;
4110 	u32 sid = current_sid();
4111 	int rc;
4112 
4113 	if (file == NULL)
4114 		return avc_has_perm(sid, sid, SECCLASS_SYSTEM, requested, NULL);
4115 
4116 	ad.type = LSM_AUDIT_DATA_FILE;
4117 	ad.u.file = file;
4118 
4119 	fsec = selinux_file(file);
4120 	if (sid != fsec->sid) {
4121 		rc = avc_has_perm(sid, fsec->sid, SECCLASS_FD, FD__USE, &ad);
4122 		if (rc)
4123 			return rc;
4124 	}
4125 
4126 	isec = inode_security(file_inode(file));
4127 	return avc_has_perm(sid, isec->sid, SECCLASS_SYSTEM, requested, &ad);
4128 }
4129 
selinux_kernel_read_file(struct file * file,enum kernel_read_file_id id,bool contents)4130 static int selinux_kernel_read_file(struct file *file,
4131 				    enum kernel_read_file_id id,
4132 				    bool contents)
4133 {
4134 	int rc = 0;
4135 
4136 	BUILD_BUG_ON_MSG(READING_MAX_ID > 7,
4137 			 "New kernel_read_file_id introduced; update SELinux!");
4138 
4139 	switch (id) {
4140 	case READING_FIRMWARE:
4141 		rc = selinux_kernel_load_from_file(file, SYSTEM__FIRMWARE_LOAD);
4142 		break;
4143 	case READING_MODULE:
4144 		rc = selinux_kernel_load_from_file(file, SYSTEM__MODULE_LOAD);
4145 		break;
4146 	case READING_KEXEC_IMAGE:
4147 		rc = selinux_kernel_load_from_file(file,
4148 						   SYSTEM__KEXEC_IMAGE_LOAD);
4149 		break;
4150 	case READING_KEXEC_INITRAMFS:
4151 		rc = selinux_kernel_load_from_file(file,
4152 						SYSTEM__KEXEC_INITRAMFS_LOAD);
4153 		break;
4154 	case READING_POLICY:
4155 		rc = selinux_kernel_load_from_file(file, SYSTEM__POLICY_LOAD);
4156 		break;
4157 	case READING_X509_CERTIFICATE:
4158 		rc = selinux_kernel_load_from_file(file,
4159 						SYSTEM__X509_CERTIFICATE_LOAD);
4160 		break;
4161 	default:
4162 		break;
4163 	}
4164 
4165 	return rc;
4166 }
4167 
selinux_kernel_load_data(enum kernel_load_data_id id,bool contents)4168 static int selinux_kernel_load_data(enum kernel_load_data_id id, bool contents)
4169 {
4170 	int rc = 0;
4171 
4172 	BUILD_BUG_ON_MSG(LOADING_MAX_ID > 7,
4173 			 "New kernel_load_data_id introduced; update SELinux!");
4174 
4175 	switch (id) {
4176 	case LOADING_FIRMWARE:
4177 		rc = selinux_kernel_load_from_file(NULL, SYSTEM__FIRMWARE_LOAD);
4178 		break;
4179 	case LOADING_MODULE:
4180 		rc = selinux_kernel_load_from_file(NULL, SYSTEM__MODULE_LOAD);
4181 		break;
4182 	case LOADING_KEXEC_IMAGE:
4183 		rc = selinux_kernel_load_from_file(NULL,
4184 						   SYSTEM__KEXEC_IMAGE_LOAD);
4185 		break;
4186 	case LOADING_KEXEC_INITRAMFS:
4187 		rc = selinux_kernel_load_from_file(NULL,
4188 						SYSTEM__KEXEC_INITRAMFS_LOAD);
4189 		break;
4190 	case LOADING_POLICY:
4191 		rc = selinux_kernel_load_from_file(NULL,
4192 						   SYSTEM__POLICY_LOAD);
4193 		break;
4194 	case LOADING_X509_CERTIFICATE:
4195 		rc = selinux_kernel_load_from_file(NULL,
4196 						SYSTEM__X509_CERTIFICATE_LOAD);
4197 		break;
4198 	default:
4199 		break;
4200 	}
4201 
4202 	return rc;
4203 }
4204 
selinux_task_setpgid(struct task_struct * p,pid_t pgid)4205 static int selinux_task_setpgid(struct task_struct *p, pid_t pgid)
4206 {
4207 	return avc_has_perm(current_sid(), task_sid_obj(p), SECCLASS_PROCESS,
4208 			    PROCESS__SETPGID, NULL);
4209 }
4210 
selinux_task_getpgid(struct task_struct * p)4211 static int selinux_task_getpgid(struct task_struct *p)
4212 {
4213 	return avc_has_perm(current_sid(), task_sid_obj(p), SECCLASS_PROCESS,
4214 			    PROCESS__GETPGID, NULL);
4215 }
4216 
selinux_task_getsid(struct task_struct * p)4217 static int selinux_task_getsid(struct task_struct *p)
4218 {
4219 	return avc_has_perm(current_sid(), task_sid_obj(p), SECCLASS_PROCESS,
4220 			    PROCESS__GETSESSION, NULL);
4221 }
4222 
selinux_current_getlsmprop_subj(struct lsm_prop * prop)4223 static void selinux_current_getlsmprop_subj(struct lsm_prop *prop)
4224 {
4225 	prop->selinux.secid = current_sid();
4226 }
4227 
selinux_task_getlsmprop_obj(struct task_struct * p,struct lsm_prop * prop)4228 static void selinux_task_getlsmprop_obj(struct task_struct *p,
4229 					struct lsm_prop *prop)
4230 {
4231 	prop->selinux.secid = task_sid_obj(p);
4232 }
4233 
selinux_task_setnice(struct task_struct * p,int nice)4234 static int selinux_task_setnice(struct task_struct *p, int nice)
4235 {
4236 	return avc_has_perm(current_sid(), task_sid_obj(p), SECCLASS_PROCESS,
4237 			    PROCESS__SETSCHED, NULL);
4238 }
4239 
selinux_task_setioprio(struct task_struct * p,int ioprio)4240 static int selinux_task_setioprio(struct task_struct *p, int ioprio)
4241 {
4242 	return avc_has_perm(current_sid(), task_sid_obj(p), SECCLASS_PROCESS,
4243 			    PROCESS__SETSCHED, NULL);
4244 }
4245 
selinux_task_getioprio(struct task_struct * p)4246 static int selinux_task_getioprio(struct task_struct *p)
4247 {
4248 	return avc_has_perm(current_sid(), task_sid_obj(p), SECCLASS_PROCESS,
4249 			    PROCESS__GETSCHED, NULL);
4250 }
4251 
selinux_task_prlimit(const struct cred * cred,const struct cred * tcred,unsigned int flags)4252 static int selinux_task_prlimit(const struct cred *cred, const struct cred *tcred,
4253 				unsigned int flags)
4254 {
4255 	u32 av = 0;
4256 
4257 	if (!flags)
4258 		return 0;
4259 	if (flags & LSM_PRLIMIT_WRITE)
4260 		av |= PROCESS__SETRLIMIT;
4261 	if (flags & LSM_PRLIMIT_READ)
4262 		av |= PROCESS__GETRLIMIT;
4263 	return avc_has_perm(cred_sid(cred), cred_sid(tcred),
4264 			    SECCLASS_PROCESS, av, NULL);
4265 }
4266 
selinux_task_setrlimit(struct task_struct * p,unsigned int resource,struct rlimit * new_rlim)4267 static int selinux_task_setrlimit(struct task_struct *p, unsigned int resource,
4268 		struct rlimit *new_rlim)
4269 {
4270 	struct rlimit *old_rlim = p->signal->rlim + resource;
4271 
4272 	/* Control the ability to change the hard limit (whether
4273 	   lowering or raising it), so that the hard limit can
4274 	   later be used as a safe reset point for the soft limit
4275 	   upon context transitions.  See selinux_bprm_committing_creds. */
4276 	if (old_rlim->rlim_max != new_rlim->rlim_max)
4277 		return avc_has_perm(current_sid(), task_sid_obj(p),
4278 				    SECCLASS_PROCESS, PROCESS__SETRLIMIT, NULL);
4279 
4280 	return 0;
4281 }
4282 
selinux_task_setscheduler(struct task_struct * p)4283 static int selinux_task_setscheduler(struct task_struct *p)
4284 {
4285 	return avc_has_perm(current_sid(), task_sid_obj(p), SECCLASS_PROCESS,
4286 			    PROCESS__SETSCHED, NULL);
4287 }
4288 
selinux_task_getscheduler(struct task_struct * p)4289 static int selinux_task_getscheduler(struct task_struct *p)
4290 {
4291 	return avc_has_perm(current_sid(), task_sid_obj(p), SECCLASS_PROCESS,
4292 			    PROCESS__GETSCHED, NULL);
4293 }
4294 
selinux_task_movememory(struct task_struct * p)4295 static int selinux_task_movememory(struct task_struct *p)
4296 {
4297 	return avc_has_perm(current_sid(), task_sid_obj(p), SECCLASS_PROCESS,
4298 			    PROCESS__SETSCHED, NULL);
4299 }
4300 
selinux_task_kill(struct task_struct * p,struct kernel_siginfo * info,int sig,const struct cred * cred)4301 static int selinux_task_kill(struct task_struct *p, struct kernel_siginfo *info,
4302 				int sig, const struct cred *cred)
4303 {
4304 	u32 secid;
4305 	u32 perm;
4306 
4307 	if (!sig)
4308 		perm = PROCESS__SIGNULL; /* null signal; existence test */
4309 	else
4310 		perm = signal_to_av(sig);
4311 	if (!cred)
4312 		secid = current_sid();
4313 	else
4314 		secid = cred_sid(cred);
4315 	return avc_has_perm(secid, task_sid_obj(p), SECCLASS_PROCESS, perm, NULL);
4316 }
4317 
selinux_task_to_inode(struct task_struct * p,struct inode * inode)4318 static void selinux_task_to_inode(struct task_struct *p,
4319 				  struct inode *inode)
4320 {
4321 	struct inode_security_struct *isec = selinux_inode(inode);
4322 	u32 sid = task_sid_obj(p);
4323 
4324 	spin_lock(&isec->lock);
4325 	isec->sclass = inode_mode_to_security_class(inode->i_mode);
4326 	isec->sid = sid;
4327 	isec->initialized = LABEL_INITIALIZED;
4328 	spin_unlock(&isec->lock);
4329 }
4330 
selinux_userns_create(const struct cred * cred)4331 static int selinux_userns_create(const struct cred *cred)
4332 {
4333 	u32 sid = current_sid();
4334 
4335 	return avc_has_perm(sid, sid, SECCLASS_USER_NAMESPACE,
4336 			USER_NAMESPACE__CREATE, NULL);
4337 }
4338 
4339 /* Returns error only if unable to parse addresses */
selinux_parse_skb_ipv4(struct sk_buff * skb,struct common_audit_data * ad,u8 * proto)4340 static int selinux_parse_skb_ipv4(struct sk_buff *skb,
4341 			struct common_audit_data *ad, u8 *proto)
4342 {
4343 	int offset, ihlen, ret = -EINVAL;
4344 	struct iphdr _iph, *ih;
4345 
4346 	offset = skb_network_offset(skb);
4347 	ih = skb_header_pointer(skb, offset, sizeof(_iph), &_iph);
4348 	if (ih == NULL)
4349 		goto out;
4350 
4351 	ihlen = ih->ihl * 4;
4352 	if (ihlen < sizeof(_iph))
4353 		goto out;
4354 
4355 	ad->u.net->v4info.saddr = ih->saddr;
4356 	ad->u.net->v4info.daddr = ih->daddr;
4357 	ret = 0;
4358 
4359 	if (proto)
4360 		*proto = ih->protocol;
4361 
4362 	switch (ih->protocol) {
4363 	case IPPROTO_TCP: {
4364 		struct tcphdr _tcph, *th;
4365 
4366 		if (ntohs(ih->frag_off) & IP_OFFSET)
4367 			break;
4368 
4369 		offset += ihlen;
4370 		th = skb_header_pointer(skb, offset, sizeof(_tcph), &_tcph);
4371 		if (th == NULL)
4372 			break;
4373 
4374 		ad->u.net->sport = th->source;
4375 		ad->u.net->dport = th->dest;
4376 		break;
4377 	}
4378 
4379 	case IPPROTO_UDP: {
4380 		struct udphdr _udph, *uh;
4381 
4382 		if (ntohs(ih->frag_off) & IP_OFFSET)
4383 			break;
4384 
4385 		offset += ihlen;
4386 		uh = skb_header_pointer(skb, offset, sizeof(_udph), &_udph);
4387 		if (uh == NULL)
4388 			break;
4389 
4390 		ad->u.net->sport = uh->source;
4391 		ad->u.net->dport = uh->dest;
4392 		break;
4393 	}
4394 
4395 	case IPPROTO_DCCP: {
4396 		struct dccp_hdr _dccph, *dh;
4397 
4398 		if (ntohs(ih->frag_off) & IP_OFFSET)
4399 			break;
4400 
4401 		offset += ihlen;
4402 		dh = skb_header_pointer(skb, offset, sizeof(_dccph), &_dccph);
4403 		if (dh == NULL)
4404 			break;
4405 
4406 		ad->u.net->sport = dh->dccph_sport;
4407 		ad->u.net->dport = dh->dccph_dport;
4408 		break;
4409 	}
4410 
4411 #if IS_ENABLED(CONFIG_IP_SCTP)
4412 	case IPPROTO_SCTP: {
4413 		struct sctphdr _sctph, *sh;
4414 
4415 		if (ntohs(ih->frag_off) & IP_OFFSET)
4416 			break;
4417 
4418 		offset += ihlen;
4419 		sh = skb_header_pointer(skb, offset, sizeof(_sctph), &_sctph);
4420 		if (sh == NULL)
4421 			break;
4422 
4423 		ad->u.net->sport = sh->source;
4424 		ad->u.net->dport = sh->dest;
4425 		break;
4426 	}
4427 #endif
4428 	default:
4429 		break;
4430 	}
4431 out:
4432 	return ret;
4433 }
4434 
4435 #if IS_ENABLED(CONFIG_IPV6)
4436 
4437 /* Returns error only if unable to parse addresses */
selinux_parse_skb_ipv6(struct sk_buff * skb,struct common_audit_data * ad,u8 * proto)4438 static int selinux_parse_skb_ipv6(struct sk_buff *skb,
4439 			struct common_audit_data *ad, u8 *proto)
4440 {
4441 	u8 nexthdr;
4442 	int ret = -EINVAL, offset;
4443 	struct ipv6hdr _ipv6h, *ip6;
4444 	__be16 frag_off;
4445 
4446 	offset = skb_network_offset(skb);
4447 	ip6 = skb_header_pointer(skb, offset, sizeof(_ipv6h), &_ipv6h);
4448 	if (ip6 == NULL)
4449 		goto out;
4450 
4451 	ad->u.net->v6info.saddr = ip6->saddr;
4452 	ad->u.net->v6info.daddr = ip6->daddr;
4453 	ret = 0;
4454 
4455 	nexthdr = ip6->nexthdr;
4456 	offset += sizeof(_ipv6h);
4457 	offset = ipv6_skip_exthdr(skb, offset, &nexthdr, &frag_off);
4458 	if (offset < 0)
4459 		goto out;
4460 
4461 	if (proto)
4462 		*proto = nexthdr;
4463 
4464 	switch (nexthdr) {
4465 	case IPPROTO_TCP: {
4466 		struct tcphdr _tcph, *th;
4467 
4468 		th = skb_header_pointer(skb, offset, sizeof(_tcph), &_tcph);
4469 		if (th == NULL)
4470 			break;
4471 
4472 		ad->u.net->sport = th->source;
4473 		ad->u.net->dport = th->dest;
4474 		break;
4475 	}
4476 
4477 	case IPPROTO_UDP: {
4478 		struct udphdr _udph, *uh;
4479 
4480 		uh = skb_header_pointer(skb, offset, sizeof(_udph), &_udph);
4481 		if (uh == NULL)
4482 			break;
4483 
4484 		ad->u.net->sport = uh->source;
4485 		ad->u.net->dport = uh->dest;
4486 		break;
4487 	}
4488 
4489 	case IPPROTO_DCCP: {
4490 		struct dccp_hdr _dccph, *dh;
4491 
4492 		dh = skb_header_pointer(skb, offset, sizeof(_dccph), &_dccph);
4493 		if (dh == NULL)
4494 			break;
4495 
4496 		ad->u.net->sport = dh->dccph_sport;
4497 		ad->u.net->dport = dh->dccph_dport;
4498 		break;
4499 	}
4500 
4501 #if IS_ENABLED(CONFIG_IP_SCTP)
4502 	case IPPROTO_SCTP: {
4503 		struct sctphdr _sctph, *sh;
4504 
4505 		sh = skb_header_pointer(skb, offset, sizeof(_sctph), &_sctph);
4506 		if (sh == NULL)
4507 			break;
4508 
4509 		ad->u.net->sport = sh->source;
4510 		ad->u.net->dport = sh->dest;
4511 		break;
4512 	}
4513 #endif
4514 	/* includes fragments */
4515 	default:
4516 		break;
4517 	}
4518 out:
4519 	return ret;
4520 }
4521 
4522 #endif /* IPV6 */
4523 
selinux_parse_skb(struct sk_buff * skb,struct common_audit_data * ad,char ** _addrp,int src,u8 * proto)4524 static int selinux_parse_skb(struct sk_buff *skb, struct common_audit_data *ad,
4525 			     char **_addrp, int src, u8 *proto)
4526 {
4527 	char *addrp;
4528 	int ret;
4529 
4530 	switch (ad->u.net->family) {
4531 	case PF_INET:
4532 		ret = selinux_parse_skb_ipv4(skb, ad, proto);
4533 		if (ret)
4534 			goto parse_error;
4535 		addrp = (char *)(src ? &ad->u.net->v4info.saddr :
4536 				       &ad->u.net->v4info.daddr);
4537 		goto okay;
4538 
4539 #if IS_ENABLED(CONFIG_IPV6)
4540 	case PF_INET6:
4541 		ret = selinux_parse_skb_ipv6(skb, ad, proto);
4542 		if (ret)
4543 			goto parse_error;
4544 		addrp = (char *)(src ? &ad->u.net->v6info.saddr :
4545 				       &ad->u.net->v6info.daddr);
4546 		goto okay;
4547 #endif	/* IPV6 */
4548 	default:
4549 		addrp = NULL;
4550 		goto okay;
4551 	}
4552 
4553 parse_error:
4554 	pr_warn(
4555 	       "SELinux: failure in selinux_parse_skb(),"
4556 	       " unable to parse packet\n");
4557 	return ret;
4558 
4559 okay:
4560 	if (_addrp)
4561 		*_addrp = addrp;
4562 	return 0;
4563 }
4564 
4565 /**
4566  * selinux_skb_peerlbl_sid - Determine the peer label of a packet
4567  * @skb: the packet
4568  * @family: protocol family
4569  * @sid: the packet's peer label SID
4570  *
4571  * Description:
4572  * Check the various different forms of network peer labeling and determine
4573  * the peer label/SID for the packet; most of the magic actually occurs in
4574  * the security server function security_net_peersid_cmp().  The function
4575  * returns zero if the value in @sid is valid (although it may be SECSID_NULL)
4576  * or -EACCES if @sid is invalid due to inconsistencies with the different
4577  * peer labels.
4578  *
4579  */
selinux_skb_peerlbl_sid(struct sk_buff * skb,u16 family,u32 * sid)4580 static int selinux_skb_peerlbl_sid(struct sk_buff *skb, u16 family, u32 *sid)
4581 {
4582 	int err;
4583 	u32 xfrm_sid;
4584 	u32 nlbl_sid;
4585 	u32 nlbl_type;
4586 
4587 	err = selinux_xfrm_skb_sid(skb, &xfrm_sid);
4588 	if (unlikely(err))
4589 		return -EACCES;
4590 	err = selinux_netlbl_skbuff_getsid(skb, family, &nlbl_type, &nlbl_sid);
4591 	if (unlikely(err))
4592 		return -EACCES;
4593 
4594 	err = security_net_peersid_resolve(nlbl_sid,
4595 					   nlbl_type, xfrm_sid, sid);
4596 	if (unlikely(err)) {
4597 		pr_warn(
4598 		       "SELinux: failure in selinux_skb_peerlbl_sid(),"
4599 		       " unable to determine packet's peer label\n");
4600 		return -EACCES;
4601 	}
4602 
4603 	return 0;
4604 }
4605 
4606 /**
4607  * selinux_conn_sid - Determine the child socket label for a connection
4608  * @sk_sid: the parent socket's SID
4609  * @skb_sid: the packet's SID
4610  * @conn_sid: the resulting connection SID
4611  *
4612  * If @skb_sid is valid then the user:role:type information from @sk_sid is
4613  * combined with the MLS information from @skb_sid in order to create
4614  * @conn_sid.  If @skb_sid is not valid then @conn_sid is simply a copy
4615  * of @sk_sid.  Returns zero on success, negative values on failure.
4616  *
4617  */
selinux_conn_sid(u32 sk_sid,u32 skb_sid,u32 * conn_sid)4618 static int selinux_conn_sid(u32 sk_sid, u32 skb_sid, u32 *conn_sid)
4619 {
4620 	int err = 0;
4621 
4622 	if (skb_sid != SECSID_NULL)
4623 		err = security_sid_mls_copy(sk_sid, skb_sid,
4624 					    conn_sid);
4625 	else
4626 		*conn_sid = sk_sid;
4627 
4628 	return err;
4629 }
4630 
4631 /* socket security operations */
4632 
socket_sockcreate_sid(const struct task_security_struct * tsec,u16 secclass,u32 * socksid)4633 static int socket_sockcreate_sid(const struct task_security_struct *tsec,
4634 				 u16 secclass, u32 *socksid)
4635 {
4636 	if (tsec->sockcreate_sid > SECSID_NULL) {
4637 		*socksid = tsec->sockcreate_sid;
4638 		return 0;
4639 	}
4640 
4641 	return security_transition_sid(tsec->sid, tsec->sid,
4642 				       secclass, NULL, socksid);
4643 }
4644 
sock_skip_has_perm(u32 sid)4645 static bool sock_skip_has_perm(u32 sid)
4646 {
4647 	if (sid == SECINITSID_KERNEL)
4648 		return true;
4649 
4650 	/*
4651 	 * Before POLICYDB_CAP_USERSPACE_INITIAL_CONTEXT, sockets that
4652 	 * inherited the kernel context from early boot used to be skipped
4653 	 * here, so preserve that behavior unless the capability is set.
4654 	 *
4655 	 * By setting the capability the policy signals that it is ready
4656 	 * for this quirk to be fixed. Note that sockets created by a kernel
4657 	 * thread or a usermode helper executed without a transition will
4658 	 * still be skipped in this check regardless of the policycap
4659 	 * setting.
4660 	 */
4661 	if (!selinux_policycap_userspace_initial_context() &&
4662 	    sid == SECINITSID_INIT)
4663 		return true;
4664 	return false;
4665 }
4666 
4667 
sock_has_perm(struct sock * sk,u32 perms)4668 static int sock_has_perm(struct sock *sk, u32 perms)
4669 {
4670 	struct sk_security_struct *sksec = sk->sk_security;
4671 	struct common_audit_data ad;
4672 	struct lsm_network_audit net;
4673 
4674 	if (sock_skip_has_perm(sksec->sid))
4675 		return 0;
4676 
4677 	ad_net_init_from_sk(&ad, &net, sk);
4678 
4679 	return avc_has_perm(current_sid(), sksec->sid, sksec->sclass, perms,
4680 			    &ad);
4681 }
4682 
selinux_socket_create(int family,int type,int protocol,int kern)4683 static int selinux_socket_create(int family, int type,
4684 				 int protocol, int kern)
4685 {
4686 	const struct task_security_struct *tsec = selinux_cred(current_cred());
4687 	u32 newsid;
4688 	u16 secclass;
4689 	int rc;
4690 
4691 	if (kern)
4692 		return 0;
4693 
4694 	secclass = socket_type_to_security_class(family, type, protocol);
4695 	rc = socket_sockcreate_sid(tsec, secclass, &newsid);
4696 	if (rc)
4697 		return rc;
4698 
4699 	return avc_has_perm(tsec->sid, newsid, secclass, SOCKET__CREATE, NULL);
4700 }
4701 
selinux_socket_post_create(struct socket * sock,int family,int type,int protocol,int kern)4702 static int selinux_socket_post_create(struct socket *sock, int family,
4703 				      int type, int protocol, int kern)
4704 {
4705 	const struct task_security_struct *tsec = selinux_cred(current_cred());
4706 	struct inode_security_struct *isec = inode_security_novalidate(SOCK_INODE(sock));
4707 	struct sk_security_struct *sksec;
4708 	u16 sclass = socket_type_to_security_class(family, type, protocol);
4709 	u32 sid = SECINITSID_KERNEL;
4710 	int err = 0;
4711 
4712 	if (!kern) {
4713 		err = socket_sockcreate_sid(tsec, sclass, &sid);
4714 		if (err)
4715 			return err;
4716 	}
4717 
4718 	isec->sclass = sclass;
4719 	isec->sid = sid;
4720 	isec->initialized = LABEL_INITIALIZED;
4721 
4722 	if (sock->sk) {
4723 		sksec = selinux_sock(sock->sk);
4724 		sksec->sclass = sclass;
4725 		sksec->sid = sid;
4726 		/* Allows detection of the first association on this socket */
4727 		if (sksec->sclass == SECCLASS_SCTP_SOCKET)
4728 			sksec->sctp_assoc_state = SCTP_ASSOC_UNSET;
4729 
4730 		err = selinux_netlbl_socket_post_create(sock->sk, family);
4731 	}
4732 
4733 	return err;
4734 }
4735 
selinux_socket_socketpair(struct socket * socka,struct socket * sockb)4736 static int selinux_socket_socketpair(struct socket *socka,
4737 				     struct socket *sockb)
4738 {
4739 	struct sk_security_struct *sksec_a = selinux_sock(socka->sk);
4740 	struct sk_security_struct *sksec_b = selinux_sock(sockb->sk);
4741 
4742 	sksec_a->peer_sid = sksec_b->sid;
4743 	sksec_b->peer_sid = sksec_a->sid;
4744 
4745 	return 0;
4746 }
4747 
4748 /* Range of port numbers used to automatically bind.
4749    Need to determine whether we should perform a name_bind
4750    permission check between the socket and the port number. */
4751 
selinux_socket_bind(struct socket * sock,struct sockaddr * address,int addrlen)4752 static int selinux_socket_bind(struct socket *sock, struct sockaddr *address, int addrlen)
4753 {
4754 	struct sock *sk = sock->sk;
4755 	struct sk_security_struct *sksec = selinux_sock(sk);
4756 	u16 family;
4757 	int err;
4758 
4759 	err = sock_has_perm(sk, SOCKET__BIND);
4760 	if (err)
4761 		goto out;
4762 
4763 	/* If PF_INET or PF_INET6, check name_bind permission for the port. */
4764 	family = sk->sk_family;
4765 	if (family == PF_INET || family == PF_INET6) {
4766 		char *addrp;
4767 		struct common_audit_data ad;
4768 		struct lsm_network_audit net = {0,};
4769 		struct sockaddr_in *addr4 = NULL;
4770 		struct sockaddr_in6 *addr6 = NULL;
4771 		u16 family_sa;
4772 		unsigned short snum;
4773 		u32 sid, node_perm;
4774 
4775 		/*
4776 		 * sctp_bindx(3) calls via selinux_sctp_bind_connect()
4777 		 * that validates multiple binding addresses. Because of this
4778 		 * need to check address->sa_family as it is possible to have
4779 		 * sk->sk_family = PF_INET6 with addr->sa_family = AF_INET.
4780 		 */
4781 		if (addrlen < offsetofend(struct sockaddr, sa_family))
4782 			return -EINVAL;
4783 		family_sa = address->sa_family;
4784 		switch (family_sa) {
4785 		case AF_UNSPEC:
4786 		case AF_INET:
4787 			if (addrlen < sizeof(struct sockaddr_in))
4788 				return -EINVAL;
4789 			addr4 = (struct sockaddr_in *)address;
4790 			if (family_sa == AF_UNSPEC) {
4791 				if (family == PF_INET6) {
4792 					/* Length check from inet6_bind_sk() */
4793 					if (addrlen < SIN6_LEN_RFC2133)
4794 						return -EINVAL;
4795 					/* Family check from __inet6_bind() */
4796 					goto err_af;
4797 				}
4798 				/* see __inet_bind(), we only want to allow
4799 				 * AF_UNSPEC if the address is INADDR_ANY
4800 				 */
4801 				if (addr4->sin_addr.s_addr != htonl(INADDR_ANY))
4802 					goto err_af;
4803 				family_sa = AF_INET;
4804 			}
4805 			snum = ntohs(addr4->sin_port);
4806 			addrp = (char *)&addr4->sin_addr.s_addr;
4807 			break;
4808 		case AF_INET6:
4809 			if (addrlen < SIN6_LEN_RFC2133)
4810 				return -EINVAL;
4811 			addr6 = (struct sockaddr_in6 *)address;
4812 			snum = ntohs(addr6->sin6_port);
4813 			addrp = (char *)&addr6->sin6_addr.s6_addr;
4814 			break;
4815 		default:
4816 			goto err_af;
4817 		}
4818 
4819 		ad.type = LSM_AUDIT_DATA_NET;
4820 		ad.u.net = &net;
4821 		ad.u.net->sport = htons(snum);
4822 		ad.u.net->family = family_sa;
4823 
4824 		if (snum) {
4825 			int low, high;
4826 
4827 			inet_get_local_port_range(sock_net(sk), &low, &high);
4828 
4829 			if (inet_port_requires_bind_service(sock_net(sk), snum) ||
4830 			    snum < low || snum > high) {
4831 				err = sel_netport_sid(sk->sk_protocol,
4832 						      snum, &sid);
4833 				if (err)
4834 					goto out;
4835 				err = avc_has_perm(sksec->sid, sid,
4836 						   sksec->sclass,
4837 						   SOCKET__NAME_BIND, &ad);
4838 				if (err)
4839 					goto out;
4840 			}
4841 		}
4842 
4843 		switch (sksec->sclass) {
4844 		case SECCLASS_TCP_SOCKET:
4845 			node_perm = TCP_SOCKET__NODE_BIND;
4846 			break;
4847 
4848 		case SECCLASS_UDP_SOCKET:
4849 			node_perm = UDP_SOCKET__NODE_BIND;
4850 			break;
4851 
4852 		case SECCLASS_DCCP_SOCKET:
4853 			node_perm = DCCP_SOCKET__NODE_BIND;
4854 			break;
4855 
4856 		case SECCLASS_SCTP_SOCKET:
4857 			node_perm = SCTP_SOCKET__NODE_BIND;
4858 			break;
4859 
4860 		default:
4861 			node_perm = RAWIP_SOCKET__NODE_BIND;
4862 			break;
4863 		}
4864 
4865 		err = sel_netnode_sid(addrp, family_sa, &sid);
4866 		if (err)
4867 			goto out;
4868 
4869 		if (family_sa == AF_INET)
4870 			ad.u.net->v4info.saddr = addr4->sin_addr.s_addr;
4871 		else
4872 			ad.u.net->v6info.saddr = addr6->sin6_addr;
4873 
4874 		err = avc_has_perm(sksec->sid, sid,
4875 				   sksec->sclass, node_perm, &ad);
4876 		if (err)
4877 			goto out;
4878 	}
4879 out:
4880 	return err;
4881 err_af:
4882 	/* Note that SCTP services expect -EINVAL, others -EAFNOSUPPORT. */
4883 	if (sk->sk_protocol == IPPROTO_SCTP)
4884 		return -EINVAL;
4885 	return -EAFNOSUPPORT;
4886 }
4887 
4888 /* This supports connect(2) and SCTP connect services such as sctp_connectx(3)
4889  * and sctp_sendmsg(3) as described in Documentation/security/SCTP.rst
4890  */
selinux_socket_connect_helper(struct socket * sock,struct sockaddr * address,int addrlen)4891 static int selinux_socket_connect_helper(struct socket *sock,
4892 					 struct sockaddr *address, int addrlen)
4893 {
4894 	struct sock *sk = sock->sk;
4895 	struct sk_security_struct *sksec = selinux_sock(sk);
4896 	int err;
4897 
4898 	err = sock_has_perm(sk, SOCKET__CONNECT);
4899 	if (err)
4900 		return err;
4901 	if (addrlen < offsetofend(struct sockaddr, sa_family))
4902 		return -EINVAL;
4903 
4904 	/* connect(AF_UNSPEC) has special handling, as it is a documented
4905 	 * way to disconnect the socket
4906 	 */
4907 	if (address->sa_family == AF_UNSPEC)
4908 		return 0;
4909 
4910 	/*
4911 	 * If a TCP, DCCP or SCTP socket, check name_connect permission
4912 	 * for the port.
4913 	 */
4914 	if (sksec->sclass == SECCLASS_TCP_SOCKET ||
4915 	    sksec->sclass == SECCLASS_DCCP_SOCKET ||
4916 	    sksec->sclass == SECCLASS_SCTP_SOCKET) {
4917 		struct common_audit_data ad;
4918 		struct lsm_network_audit net = {0,};
4919 		struct sockaddr_in *addr4 = NULL;
4920 		struct sockaddr_in6 *addr6 = NULL;
4921 		unsigned short snum;
4922 		u32 sid, perm;
4923 
4924 		/* sctp_connectx(3) calls via selinux_sctp_bind_connect()
4925 		 * that validates multiple connect addresses. Because of this
4926 		 * need to check address->sa_family as it is possible to have
4927 		 * sk->sk_family = PF_INET6 with addr->sa_family = AF_INET.
4928 		 */
4929 		switch (address->sa_family) {
4930 		case AF_INET:
4931 			addr4 = (struct sockaddr_in *)address;
4932 			if (addrlen < sizeof(struct sockaddr_in))
4933 				return -EINVAL;
4934 			snum = ntohs(addr4->sin_port);
4935 			break;
4936 		case AF_INET6:
4937 			addr6 = (struct sockaddr_in6 *)address;
4938 			if (addrlen < SIN6_LEN_RFC2133)
4939 				return -EINVAL;
4940 			snum = ntohs(addr6->sin6_port);
4941 			break;
4942 		default:
4943 			/* Note that SCTP services expect -EINVAL, whereas
4944 			 * others expect -EAFNOSUPPORT.
4945 			 */
4946 			if (sksec->sclass == SECCLASS_SCTP_SOCKET)
4947 				return -EINVAL;
4948 			else
4949 				return -EAFNOSUPPORT;
4950 		}
4951 
4952 		err = sel_netport_sid(sk->sk_protocol, snum, &sid);
4953 		if (err)
4954 			return err;
4955 
4956 		switch (sksec->sclass) {
4957 		case SECCLASS_TCP_SOCKET:
4958 			perm = TCP_SOCKET__NAME_CONNECT;
4959 			break;
4960 		case SECCLASS_DCCP_SOCKET:
4961 			perm = DCCP_SOCKET__NAME_CONNECT;
4962 			break;
4963 		case SECCLASS_SCTP_SOCKET:
4964 			perm = SCTP_SOCKET__NAME_CONNECT;
4965 			break;
4966 		}
4967 
4968 		ad.type = LSM_AUDIT_DATA_NET;
4969 		ad.u.net = &net;
4970 		ad.u.net->dport = htons(snum);
4971 		ad.u.net->family = address->sa_family;
4972 		err = avc_has_perm(sksec->sid, sid, sksec->sclass, perm, &ad);
4973 		if (err)
4974 			return err;
4975 	}
4976 
4977 	return 0;
4978 }
4979 
4980 /* Supports connect(2), see comments in selinux_socket_connect_helper() */
selinux_socket_connect(struct socket * sock,struct sockaddr * address,int addrlen)4981 static int selinux_socket_connect(struct socket *sock,
4982 				  struct sockaddr *address, int addrlen)
4983 {
4984 	int err;
4985 	struct sock *sk = sock->sk;
4986 
4987 	err = selinux_socket_connect_helper(sock, address, addrlen);
4988 	if (err)
4989 		return err;
4990 
4991 	return selinux_netlbl_socket_connect(sk, address);
4992 }
4993 
selinux_socket_listen(struct socket * sock,int backlog)4994 static int selinux_socket_listen(struct socket *sock, int backlog)
4995 {
4996 	return sock_has_perm(sock->sk, SOCKET__LISTEN);
4997 }
4998 
selinux_socket_accept(struct socket * sock,struct socket * newsock)4999 static int selinux_socket_accept(struct socket *sock, struct socket *newsock)
5000 {
5001 	int err;
5002 	struct inode_security_struct *isec;
5003 	struct inode_security_struct *newisec;
5004 	u16 sclass;
5005 	u32 sid;
5006 
5007 	err = sock_has_perm(sock->sk, SOCKET__ACCEPT);
5008 	if (err)
5009 		return err;
5010 
5011 	isec = inode_security_novalidate(SOCK_INODE(sock));
5012 	spin_lock(&isec->lock);
5013 	sclass = isec->sclass;
5014 	sid = isec->sid;
5015 	spin_unlock(&isec->lock);
5016 
5017 	newisec = inode_security_novalidate(SOCK_INODE(newsock));
5018 	newisec->sclass = sclass;
5019 	newisec->sid = sid;
5020 	newisec->initialized = LABEL_INITIALIZED;
5021 
5022 	return 0;
5023 }
5024 
selinux_socket_sendmsg(struct socket * sock,struct msghdr * msg,int size)5025 static int selinux_socket_sendmsg(struct socket *sock, struct msghdr *msg,
5026 				  int size)
5027 {
5028 	return sock_has_perm(sock->sk, SOCKET__WRITE);
5029 }
5030 
selinux_socket_recvmsg(struct socket * sock,struct msghdr * msg,int size,int flags)5031 static int selinux_socket_recvmsg(struct socket *sock, struct msghdr *msg,
5032 				  int size, int flags)
5033 {
5034 	return sock_has_perm(sock->sk, SOCKET__READ);
5035 }
5036 
selinux_socket_getsockname(struct socket * sock)5037 static int selinux_socket_getsockname(struct socket *sock)
5038 {
5039 	return sock_has_perm(sock->sk, SOCKET__GETATTR);
5040 }
5041 
selinux_socket_getpeername(struct socket * sock)5042 static int selinux_socket_getpeername(struct socket *sock)
5043 {
5044 	return sock_has_perm(sock->sk, SOCKET__GETATTR);
5045 }
5046 
selinux_socket_setsockopt(struct socket * sock,int level,int optname)5047 static int selinux_socket_setsockopt(struct socket *sock, int level, int optname)
5048 {
5049 	int err;
5050 
5051 	err = sock_has_perm(sock->sk, SOCKET__SETOPT);
5052 	if (err)
5053 		return err;
5054 
5055 	return selinux_netlbl_socket_setsockopt(sock, level, optname);
5056 }
5057 
selinux_socket_getsockopt(struct socket * sock,int level,int optname)5058 static int selinux_socket_getsockopt(struct socket *sock, int level,
5059 				     int optname)
5060 {
5061 	return sock_has_perm(sock->sk, SOCKET__GETOPT);
5062 }
5063 
selinux_socket_shutdown(struct socket * sock,int how)5064 static int selinux_socket_shutdown(struct socket *sock, int how)
5065 {
5066 	return sock_has_perm(sock->sk, SOCKET__SHUTDOWN);
5067 }
5068 
selinux_socket_unix_stream_connect(struct sock * sock,struct sock * other,struct sock * newsk)5069 static int selinux_socket_unix_stream_connect(struct sock *sock,
5070 					      struct sock *other,
5071 					      struct sock *newsk)
5072 {
5073 	struct sk_security_struct *sksec_sock = selinux_sock(sock);
5074 	struct sk_security_struct *sksec_other = selinux_sock(other);
5075 	struct sk_security_struct *sksec_new = selinux_sock(newsk);
5076 	struct common_audit_data ad;
5077 	struct lsm_network_audit net;
5078 	int err;
5079 
5080 	ad_net_init_from_sk(&ad, &net, other);
5081 
5082 	err = avc_has_perm(sksec_sock->sid, sksec_other->sid,
5083 			   sksec_other->sclass,
5084 			   UNIX_STREAM_SOCKET__CONNECTTO, &ad);
5085 	if (err)
5086 		return err;
5087 
5088 	/* server child socket */
5089 	sksec_new->peer_sid = sksec_sock->sid;
5090 	err = security_sid_mls_copy(sksec_other->sid,
5091 				    sksec_sock->sid, &sksec_new->sid);
5092 	if (err)
5093 		return err;
5094 
5095 	/* connecting socket */
5096 	sksec_sock->peer_sid = sksec_new->sid;
5097 
5098 	return 0;
5099 }
5100 
selinux_socket_unix_may_send(struct socket * sock,struct socket * other)5101 static int selinux_socket_unix_may_send(struct socket *sock,
5102 					struct socket *other)
5103 {
5104 	struct sk_security_struct *ssec = selinux_sock(sock->sk);
5105 	struct sk_security_struct *osec = selinux_sock(other->sk);
5106 	struct common_audit_data ad;
5107 	struct lsm_network_audit net;
5108 
5109 	ad_net_init_from_sk(&ad, &net, other->sk);
5110 
5111 	return avc_has_perm(ssec->sid, osec->sid, osec->sclass, SOCKET__SENDTO,
5112 			    &ad);
5113 }
5114 
selinux_inet_sys_rcv_skb(struct net * ns,int ifindex,char * addrp,u16 family,u32 peer_sid,struct common_audit_data * ad)5115 static int selinux_inet_sys_rcv_skb(struct net *ns, int ifindex,
5116 				    char *addrp, u16 family, u32 peer_sid,
5117 				    struct common_audit_data *ad)
5118 {
5119 	int err;
5120 	u32 if_sid;
5121 	u32 node_sid;
5122 
5123 	err = sel_netif_sid(ns, ifindex, &if_sid);
5124 	if (err)
5125 		return err;
5126 	err = avc_has_perm(peer_sid, if_sid,
5127 			   SECCLASS_NETIF, NETIF__INGRESS, ad);
5128 	if (err)
5129 		return err;
5130 
5131 	err = sel_netnode_sid(addrp, family, &node_sid);
5132 	if (err)
5133 		return err;
5134 	return avc_has_perm(peer_sid, node_sid,
5135 			    SECCLASS_NODE, NODE__RECVFROM, ad);
5136 }
5137 
selinux_sock_rcv_skb_compat(struct sock * sk,struct sk_buff * skb,u16 family)5138 static int selinux_sock_rcv_skb_compat(struct sock *sk, struct sk_buff *skb,
5139 				       u16 family)
5140 {
5141 	int err = 0;
5142 	struct sk_security_struct *sksec = selinux_sock(sk);
5143 	u32 sk_sid = sksec->sid;
5144 	struct common_audit_data ad;
5145 	struct lsm_network_audit net;
5146 	char *addrp;
5147 
5148 	ad_net_init_from_iif(&ad, &net, skb->skb_iif, family);
5149 	err = selinux_parse_skb(skb, &ad, &addrp, 1, NULL);
5150 	if (err)
5151 		return err;
5152 
5153 	if (selinux_secmark_enabled()) {
5154 		err = avc_has_perm(sk_sid, skb->secmark, SECCLASS_PACKET,
5155 				   PACKET__RECV, &ad);
5156 		if (err)
5157 			return err;
5158 	}
5159 
5160 	err = selinux_netlbl_sock_rcv_skb(sksec, skb, family, &ad);
5161 	if (err)
5162 		return err;
5163 	err = selinux_xfrm_sock_rcv_skb(sksec->sid, skb, &ad);
5164 
5165 	return err;
5166 }
5167 
selinux_socket_sock_rcv_skb(struct sock * sk,struct sk_buff * skb)5168 static int selinux_socket_sock_rcv_skb(struct sock *sk, struct sk_buff *skb)
5169 {
5170 	int err, peerlbl_active, secmark_active;
5171 	struct sk_security_struct *sksec = selinux_sock(sk);
5172 	u16 family = sk->sk_family;
5173 	u32 sk_sid = sksec->sid;
5174 	struct common_audit_data ad;
5175 	struct lsm_network_audit net;
5176 	char *addrp;
5177 
5178 	if (family != PF_INET && family != PF_INET6)
5179 		return 0;
5180 
5181 	/* Handle mapped IPv4 packets arriving via IPv6 sockets */
5182 	if (family == PF_INET6 && skb->protocol == htons(ETH_P_IP))
5183 		family = PF_INET;
5184 
5185 	/* If any sort of compatibility mode is enabled then handoff processing
5186 	 * to the selinux_sock_rcv_skb_compat() function to deal with the
5187 	 * special handling.  We do this in an attempt to keep this function
5188 	 * as fast and as clean as possible. */
5189 	if (!selinux_policycap_netpeer())
5190 		return selinux_sock_rcv_skb_compat(sk, skb, family);
5191 
5192 	secmark_active = selinux_secmark_enabled();
5193 	peerlbl_active = selinux_peerlbl_enabled();
5194 	if (!secmark_active && !peerlbl_active)
5195 		return 0;
5196 
5197 	ad_net_init_from_iif(&ad, &net, skb->skb_iif, family);
5198 	err = selinux_parse_skb(skb, &ad, &addrp, 1, NULL);
5199 	if (err)
5200 		return err;
5201 
5202 	if (peerlbl_active) {
5203 		u32 peer_sid;
5204 
5205 		err = selinux_skb_peerlbl_sid(skb, family, &peer_sid);
5206 		if (err)
5207 			return err;
5208 		err = selinux_inet_sys_rcv_skb(sock_net(sk), skb->skb_iif,
5209 					       addrp, family, peer_sid, &ad);
5210 		if (err) {
5211 			selinux_netlbl_err(skb, family, err, 0);
5212 			return err;
5213 		}
5214 		err = avc_has_perm(sk_sid, peer_sid, SECCLASS_PEER,
5215 				   PEER__RECV, &ad);
5216 		if (err) {
5217 			selinux_netlbl_err(skb, family, err, 0);
5218 			return err;
5219 		}
5220 	}
5221 
5222 	if (secmark_active) {
5223 		err = avc_has_perm(sk_sid, skb->secmark, SECCLASS_PACKET,
5224 				   PACKET__RECV, &ad);
5225 		if (err)
5226 			return err;
5227 	}
5228 
5229 	return err;
5230 }
5231 
selinux_socket_getpeersec_stream(struct socket * sock,sockptr_t optval,sockptr_t optlen,unsigned int len)5232 static int selinux_socket_getpeersec_stream(struct socket *sock,
5233 					    sockptr_t optval, sockptr_t optlen,
5234 					    unsigned int len)
5235 {
5236 	int err = 0;
5237 	char *scontext = NULL;
5238 	u32 scontext_len;
5239 	struct sk_security_struct *sksec = selinux_sock(sock->sk);
5240 	u32 peer_sid = SECSID_NULL;
5241 
5242 	if (sksec->sclass == SECCLASS_UNIX_STREAM_SOCKET ||
5243 	    sksec->sclass == SECCLASS_TCP_SOCKET ||
5244 	    sksec->sclass == SECCLASS_SCTP_SOCKET)
5245 		peer_sid = sksec->peer_sid;
5246 	if (peer_sid == SECSID_NULL)
5247 		return -ENOPROTOOPT;
5248 
5249 	err = security_sid_to_context(peer_sid, &scontext,
5250 				      &scontext_len);
5251 	if (err)
5252 		return err;
5253 	if (scontext_len > len) {
5254 		err = -ERANGE;
5255 		goto out_len;
5256 	}
5257 
5258 	if (copy_to_sockptr(optval, scontext, scontext_len))
5259 		err = -EFAULT;
5260 out_len:
5261 	if (copy_to_sockptr(optlen, &scontext_len, sizeof(scontext_len)))
5262 		err = -EFAULT;
5263 	kfree(scontext);
5264 	return err;
5265 }
5266 
selinux_socket_getpeersec_dgram(struct socket * sock,struct sk_buff * skb,u32 * secid)5267 static int selinux_socket_getpeersec_dgram(struct socket *sock,
5268 					   struct sk_buff *skb, u32 *secid)
5269 {
5270 	u32 peer_secid = SECSID_NULL;
5271 	u16 family;
5272 
5273 	if (skb && skb->protocol == htons(ETH_P_IP))
5274 		family = PF_INET;
5275 	else if (skb && skb->protocol == htons(ETH_P_IPV6))
5276 		family = PF_INET6;
5277 	else if (sock)
5278 		family = sock->sk->sk_family;
5279 	else {
5280 		*secid = SECSID_NULL;
5281 		return -EINVAL;
5282 	}
5283 
5284 	if (sock && family == PF_UNIX) {
5285 		struct inode_security_struct *isec;
5286 		isec = inode_security_novalidate(SOCK_INODE(sock));
5287 		peer_secid = isec->sid;
5288 	} else if (skb)
5289 		selinux_skb_peerlbl_sid(skb, family, &peer_secid);
5290 
5291 	*secid = peer_secid;
5292 	if (peer_secid == SECSID_NULL)
5293 		return -ENOPROTOOPT;
5294 	return 0;
5295 }
5296 
selinux_sk_alloc_security(struct sock * sk,int family,gfp_t priority)5297 static int selinux_sk_alloc_security(struct sock *sk, int family, gfp_t priority)
5298 {
5299 	struct sk_security_struct *sksec = selinux_sock(sk);
5300 
5301 	sksec->peer_sid = SECINITSID_UNLABELED;
5302 	sksec->sid = SECINITSID_UNLABELED;
5303 	sksec->sclass = SECCLASS_SOCKET;
5304 	selinux_netlbl_sk_security_reset(sksec);
5305 
5306 	return 0;
5307 }
5308 
selinux_sk_free_security(struct sock * sk)5309 static void selinux_sk_free_security(struct sock *sk)
5310 {
5311 	struct sk_security_struct *sksec = selinux_sock(sk);
5312 
5313 	selinux_netlbl_sk_security_free(sksec);
5314 }
5315 
selinux_sk_clone_security(const struct sock * sk,struct sock * newsk)5316 static void selinux_sk_clone_security(const struct sock *sk, struct sock *newsk)
5317 {
5318 	struct sk_security_struct *sksec = selinux_sock(sk);
5319 	struct sk_security_struct *newsksec = selinux_sock(newsk);
5320 
5321 	newsksec->sid = sksec->sid;
5322 	newsksec->peer_sid = sksec->peer_sid;
5323 	newsksec->sclass = sksec->sclass;
5324 
5325 	selinux_netlbl_sk_security_reset(newsksec);
5326 }
5327 
selinux_sk_getsecid(const struct sock * sk,u32 * secid)5328 static void selinux_sk_getsecid(const struct sock *sk, u32 *secid)
5329 {
5330 	if (!sk)
5331 		*secid = SECINITSID_ANY_SOCKET;
5332 	else {
5333 		const struct sk_security_struct *sksec = selinux_sock(sk);
5334 
5335 		*secid = sksec->sid;
5336 	}
5337 }
5338 
selinux_sock_graft(struct sock * sk,struct socket * parent)5339 static void selinux_sock_graft(struct sock *sk, struct socket *parent)
5340 {
5341 	struct inode_security_struct *isec =
5342 		inode_security_novalidate(SOCK_INODE(parent));
5343 	struct sk_security_struct *sksec = selinux_sock(sk);
5344 
5345 	if (sk->sk_family == PF_INET || sk->sk_family == PF_INET6 ||
5346 	    sk->sk_family == PF_UNIX)
5347 		isec->sid = sksec->sid;
5348 	sksec->sclass = isec->sclass;
5349 }
5350 
5351 /*
5352  * Determines peer_secid for the asoc and updates socket's peer label
5353  * if it's the first association on the socket.
5354  */
selinux_sctp_process_new_assoc(struct sctp_association * asoc,struct sk_buff * skb)5355 static int selinux_sctp_process_new_assoc(struct sctp_association *asoc,
5356 					  struct sk_buff *skb)
5357 {
5358 	struct sock *sk = asoc->base.sk;
5359 	u16 family = sk->sk_family;
5360 	struct sk_security_struct *sksec = selinux_sock(sk);
5361 	struct common_audit_data ad;
5362 	struct lsm_network_audit net;
5363 	int err;
5364 
5365 	/* handle mapped IPv4 packets arriving via IPv6 sockets */
5366 	if (family == PF_INET6 && skb->protocol == htons(ETH_P_IP))
5367 		family = PF_INET;
5368 
5369 	if (selinux_peerlbl_enabled()) {
5370 		asoc->peer_secid = SECSID_NULL;
5371 
5372 		/* This will return peer_sid = SECSID_NULL if there are
5373 		 * no peer labels, see security_net_peersid_resolve().
5374 		 */
5375 		err = selinux_skb_peerlbl_sid(skb, family, &asoc->peer_secid);
5376 		if (err)
5377 			return err;
5378 
5379 		if (asoc->peer_secid == SECSID_NULL)
5380 			asoc->peer_secid = SECINITSID_UNLABELED;
5381 	} else {
5382 		asoc->peer_secid = SECINITSID_UNLABELED;
5383 	}
5384 
5385 	if (sksec->sctp_assoc_state == SCTP_ASSOC_UNSET) {
5386 		sksec->sctp_assoc_state = SCTP_ASSOC_SET;
5387 
5388 		/* Here as first association on socket. As the peer SID
5389 		 * was allowed by peer recv (and the netif/node checks),
5390 		 * then it is approved by policy and used as the primary
5391 		 * peer SID for getpeercon(3).
5392 		 */
5393 		sksec->peer_sid = asoc->peer_secid;
5394 	} else if (sksec->peer_sid != asoc->peer_secid) {
5395 		/* Other association peer SIDs are checked to enforce
5396 		 * consistency among the peer SIDs.
5397 		 */
5398 		ad_net_init_from_sk(&ad, &net, asoc->base.sk);
5399 		err = avc_has_perm(sksec->peer_sid, asoc->peer_secid,
5400 				   sksec->sclass, SCTP_SOCKET__ASSOCIATION,
5401 				   &ad);
5402 		if (err)
5403 			return err;
5404 	}
5405 	return 0;
5406 }
5407 
5408 /* Called whenever SCTP receives an INIT or COOKIE ECHO chunk. This
5409  * happens on an incoming connect(2), sctp_connectx(3) or
5410  * sctp_sendmsg(3) (with no association already present).
5411  */
selinux_sctp_assoc_request(struct sctp_association * asoc,struct sk_buff * skb)5412 static int selinux_sctp_assoc_request(struct sctp_association *asoc,
5413 				      struct sk_buff *skb)
5414 {
5415 	struct sk_security_struct *sksec = selinux_sock(asoc->base.sk);
5416 	u32 conn_sid;
5417 	int err;
5418 
5419 	if (!selinux_policycap_extsockclass())
5420 		return 0;
5421 
5422 	err = selinux_sctp_process_new_assoc(asoc, skb);
5423 	if (err)
5424 		return err;
5425 
5426 	/* Compute the MLS component for the connection and store
5427 	 * the information in asoc. This will be used by SCTP TCP type
5428 	 * sockets and peeled off connections as they cause a new
5429 	 * socket to be generated. selinux_sctp_sk_clone() will then
5430 	 * plug this into the new socket.
5431 	 */
5432 	err = selinux_conn_sid(sksec->sid, asoc->peer_secid, &conn_sid);
5433 	if (err)
5434 		return err;
5435 
5436 	asoc->secid = conn_sid;
5437 
5438 	/* Set any NetLabel labels including CIPSO/CALIPSO options. */
5439 	return selinux_netlbl_sctp_assoc_request(asoc, skb);
5440 }
5441 
5442 /* Called when SCTP receives a COOKIE ACK chunk as the final
5443  * response to an association request (initited by us).
5444  */
selinux_sctp_assoc_established(struct sctp_association * asoc,struct sk_buff * skb)5445 static int selinux_sctp_assoc_established(struct sctp_association *asoc,
5446 					  struct sk_buff *skb)
5447 {
5448 	struct sk_security_struct *sksec = selinux_sock(asoc->base.sk);
5449 
5450 	if (!selinux_policycap_extsockclass())
5451 		return 0;
5452 
5453 	/* Inherit secid from the parent socket - this will be picked up
5454 	 * by selinux_sctp_sk_clone() if the association gets peeled off
5455 	 * into a new socket.
5456 	 */
5457 	asoc->secid = sksec->sid;
5458 
5459 	return selinux_sctp_process_new_assoc(asoc, skb);
5460 }
5461 
5462 /* Check if sctp IPv4/IPv6 addresses are valid for binding or connecting
5463  * based on their @optname.
5464  */
selinux_sctp_bind_connect(struct sock * sk,int optname,struct sockaddr * address,int addrlen)5465 static int selinux_sctp_bind_connect(struct sock *sk, int optname,
5466 				     struct sockaddr *address,
5467 				     int addrlen)
5468 {
5469 	int len, err = 0, walk_size = 0;
5470 	void *addr_buf;
5471 	struct sockaddr *addr;
5472 	struct socket *sock;
5473 
5474 	if (!selinux_policycap_extsockclass())
5475 		return 0;
5476 
5477 	/* Process one or more addresses that may be IPv4 or IPv6 */
5478 	sock = sk->sk_socket;
5479 	addr_buf = address;
5480 
5481 	while (walk_size < addrlen) {
5482 		if (walk_size + sizeof(sa_family_t) > addrlen)
5483 			return -EINVAL;
5484 
5485 		addr = addr_buf;
5486 		switch (addr->sa_family) {
5487 		case AF_UNSPEC:
5488 		case AF_INET:
5489 			len = sizeof(struct sockaddr_in);
5490 			break;
5491 		case AF_INET6:
5492 			len = sizeof(struct sockaddr_in6);
5493 			break;
5494 		default:
5495 			return -EINVAL;
5496 		}
5497 
5498 		if (walk_size + len > addrlen)
5499 			return -EINVAL;
5500 
5501 		err = -EINVAL;
5502 		switch (optname) {
5503 		/* Bind checks */
5504 		case SCTP_PRIMARY_ADDR:
5505 		case SCTP_SET_PEER_PRIMARY_ADDR:
5506 		case SCTP_SOCKOPT_BINDX_ADD:
5507 			err = selinux_socket_bind(sock, addr, len);
5508 			break;
5509 		/* Connect checks */
5510 		case SCTP_SOCKOPT_CONNECTX:
5511 		case SCTP_PARAM_SET_PRIMARY:
5512 		case SCTP_PARAM_ADD_IP:
5513 		case SCTP_SENDMSG_CONNECT:
5514 			err = selinux_socket_connect_helper(sock, addr, len);
5515 			if (err)
5516 				return err;
5517 
5518 			/* As selinux_sctp_bind_connect() is called by the
5519 			 * SCTP protocol layer, the socket is already locked,
5520 			 * therefore selinux_netlbl_socket_connect_locked()
5521 			 * is called here. The situations handled are:
5522 			 * sctp_connectx(3), sctp_sendmsg(3), sendmsg(2),
5523 			 * whenever a new IP address is added or when a new
5524 			 * primary address is selected.
5525 			 * Note that an SCTP connect(2) call happens before
5526 			 * the SCTP protocol layer and is handled via
5527 			 * selinux_socket_connect().
5528 			 */
5529 			err = selinux_netlbl_socket_connect_locked(sk, addr);
5530 			break;
5531 		}
5532 
5533 		if (err)
5534 			return err;
5535 
5536 		addr_buf += len;
5537 		walk_size += len;
5538 	}
5539 
5540 	return 0;
5541 }
5542 
5543 /* Called whenever a new socket is created by accept(2) or sctp_peeloff(3). */
selinux_sctp_sk_clone(struct sctp_association * asoc,struct sock * sk,struct sock * newsk)5544 static void selinux_sctp_sk_clone(struct sctp_association *asoc, struct sock *sk,
5545 				  struct sock *newsk)
5546 {
5547 	struct sk_security_struct *sksec = selinux_sock(sk);
5548 	struct sk_security_struct *newsksec = selinux_sock(newsk);
5549 
5550 	/* If policy does not support SECCLASS_SCTP_SOCKET then call
5551 	 * the non-sctp clone version.
5552 	 */
5553 	if (!selinux_policycap_extsockclass())
5554 		return selinux_sk_clone_security(sk, newsk);
5555 
5556 	newsksec->sid = asoc->secid;
5557 	newsksec->peer_sid = asoc->peer_secid;
5558 	newsksec->sclass = sksec->sclass;
5559 	selinux_netlbl_sctp_sk_clone(sk, newsk);
5560 }
5561 
selinux_mptcp_add_subflow(struct sock * sk,struct sock * ssk)5562 static int selinux_mptcp_add_subflow(struct sock *sk, struct sock *ssk)
5563 {
5564 	struct sk_security_struct *ssksec = selinux_sock(ssk);
5565 	struct sk_security_struct *sksec = selinux_sock(sk);
5566 
5567 	ssksec->sclass = sksec->sclass;
5568 	ssksec->sid = sksec->sid;
5569 
5570 	/* replace the existing subflow label deleting the existing one
5571 	 * and re-recreating a new label using the updated context
5572 	 */
5573 	selinux_netlbl_sk_security_free(ssksec);
5574 	return selinux_netlbl_socket_post_create(ssk, ssk->sk_family);
5575 }
5576 
selinux_inet_conn_request(const struct sock * sk,struct sk_buff * skb,struct request_sock * req)5577 static int selinux_inet_conn_request(const struct sock *sk, struct sk_buff *skb,
5578 				     struct request_sock *req)
5579 {
5580 	struct sk_security_struct *sksec = selinux_sock(sk);
5581 	int err;
5582 	u16 family = req->rsk_ops->family;
5583 	u32 connsid;
5584 	u32 peersid;
5585 
5586 	err = selinux_skb_peerlbl_sid(skb, family, &peersid);
5587 	if (err)
5588 		return err;
5589 	err = selinux_conn_sid(sksec->sid, peersid, &connsid);
5590 	if (err)
5591 		return err;
5592 	req->secid = connsid;
5593 	req->peer_secid = peersid;
5594 
5595 	return selinux_netlbl_inet_conn_request(req, family);
5596 }
5597 
selinux_inet_csk_clone(struct sock * newsk,const struct request_sock * req)5598 static void selinux_inet_csk_clone(struct sock *newsk,
5599 				   const struct request_sock *req)
5600 {
5601 	struct sk_security_struct *newsksec = selinux_sock(newsk);
5602 
5603 	newsksec->sid = req->secid;
5604 	newsksec->peer_sid = req->peer_secid;
5605 	/* NOTE: Ideally, we should also get the isec->sid for the
5606 	   new socket in sync, but we don't have the isec available yet.
5607 	   So we will wait until sock_graft to do it, by which
5608 	   time it will have been created and available. */
5609 
5610 	/* We don't need to take any sort of lock here as we are the only
5611 	 * thread with access to newsksec */
5612 	selinux_netlbl_inet_csk_clone(newsk, req->rsk_ops->family);
5613 }
5614 
selinux_inet_conn_established(struct sock * sk,struct sk_buff * skb)5615 static void selinux_inet_conn_established(struct sock *sk, struct sk_buff *skb)
5616 {
5617 	u16 family = sk->sk_family;
5618 	struct sk_security_struct *sksec = selinux_sock(sk);
5619 
5620 	/* handle mapped IPv4 packets arriving via IPv6 sockets */
5621 	if (family == PF_INET6 && skb->protocol == htons(ETH_P_IP))
5622 		family = PF_INET;
5623 
5624 	selinux_skb_peerlbl_sid(skb, family, &sksec->peer_sid);
5625 }
5626 
selinux_secmark_relabel_packet(u32 sid)5627 static int selinux_secmark_relabel_packet(u32 sid)
5628 {
5629 	return avc_has_perm(current_sid(), sid, SECCLASS_PACKET, PACKET__RELABELTO,
5630 			    NULL);
5631 }
5632 
selinux_secmark_refcount_inc(void)5633 static void selinux_secmark_refcount_inc(void)
5634 {
5635 	atomic_inc(&selinux_secmark_refcount);
5636 }
5637 
selinux_secmark_refcount_dec(void)5638 static void selinux_secmark_refcount_dec(void)
5639 {
5640 	atomic_dec(&selinux_secmark_refcount);
5641 }
5642 
selinux_req_classify_flow(const struct request_sock * req,struct flowi_common * flic)5643 static void selinux_req_classify_flow(const struct request_sock *req,
5644 				      struct flowi_common *flic)
5645 {
5646 	flic->flowic_secid = req->secid;
5647 }
5648 
selinux_tun_dev_alloc_security(void * security)5649 static int selinux_tun_dev_alloc_security(void *security)
5650 {
5651 	struct tun_security_struct *tunsec = selinux_tun_dev(security);
5652 
5653 	tunsec->sid = current_sid();
5654 	return 0;
5655 }
5656 
selinux_tun_dev_create(void)5657 static int selinux_tun_dev_create(void)
5658 {
5659 	u32 sid = current_sid();
5660 
5661 	/* we aren't taking into account the "sockcreate" SID since the socket
5662 	 * that is being created here is not a socket in the traditional sense,
5663 	 * instead it is a private sock, accessible only to the kernel, and
5664 	 * representing a wide range of network traffic spanning multiple
5665 	 * connections unlike traditional sockets - check the TUN driver to
5666 	 * get a better understanding of why this socket is special */
5667 
5668 	return avc_has_perm(sid, sid, SECCLASS_TUN_SOCKET, TUN_SOCKET__CREATE,
5669 			    NULL);
5670 }
5671 
selinux_tun_dev_attach_queue(void * security)5672 static int selinux_tun_dev_attach_queue(void *security)
5673 {
5674 	struct tun_security_struct *tunsec = selinux_tun_dev(security);
5675 
5676 	return avc_has_perm(current_sid(), tunsec->sid, SECCLASS_TUN_SOCKET,
5677 			    TUN_SOCKET__ATTACH_QUEUE, NULL);
5678 }
5679 
selinux_tun_dev_attach(struct sock * sk,void * security)5680 static int selinux_tun_dev_attach(struct sock *sk, void *security)
5681 {
5682 	struct tun_security_struct *tunsec = selinux_tun_dev(security);
5683 	struct sk_security_struct *sksec = selinux_sock(sk);
5684 
5685 	/* we don't currently perform any NetLabel based labeling here and it
5686 	 * isn't clear that we would want to do so anyway; while we could apply
5687 	 * labeling without the support of the TUN user the resulting labeled
5688 	 * traffic from the other end of the connection would almost certainly
5689 	 * cause confusion to the TUN user that had no idea network labeling
5690 	 * protocols were being used */
5691 
5692 	sksec->sid = tunsec->sid;
5693 	sksec->sclass = SECCLASS_TUN_SOCKET;
5694 
5695 	return 0;
5696 }
5697 
selinux_tun_dev_open(void * security)5698 static int selinux_tun_dev_open(void *security)
5699 {
5700 	struct tun_security_struct *tunsec = selinux_tun_dev(security);
5701 	u32 sid = current_sid();
5702 	int err;
5703 
5704 	err = avc_has_perm(sid, tunsec->sid, SECCLASS_TUN_SOCKET,
5705 			   TUN_SOCKET__RELABELFROM, NULL);
5706 	if (err)
5707 		return err;
5708 	err = avc_has_perm(sid, sid, SECCLASS_TUN_SOCKET,
5709 			   TUN_SOCKET__RELABELTO, NULL);
5710 	if (err)
5711 		return err;
5712 	tunsec->sid = sid;
5713 
5714 	return 0;
5715 }
5716 
5717 #ifdef CONFIG_NETFILTER
5718 
selinux_ip_forward(void * priv,struct sk_buff * skb,const struct nf_hook_state * state)5719 static unsigned int selinux_ip_forward(void *priv, struct sk_buff *skb,
5720 				       const struct nf_hook_state *state)
5721 {
5722 	int ifindex;
5723 	u16 family;
5724 	char *addrp;
5725 	u32 peer_sid;
5726 	struct common_audit_data ad;
5727 	struct lsm_network_audit net;
5728 	int secmark_active, peerlbl_active;
5729 
5730 	if (!selinux_policycap_netpeer())
5731 		return NF_ACCEPT;
5732 
5733 	secmark_active = selinux_secmark_enabled();
5734 	peerlbl_active = selinux_peerlbl_enabled();
5735 	if (!secmark_active && !peerlbl_active)
5736 		return NF_ACCEPT;
5737 
5738 	family = state->pf;
5739 	if (selinux_skb_peerlbl_sid(skb, family, &peer_sid) != 0)
5740 		return NF_DROP;
5741 
5742 	ifindex = state->in->ifindex;
5743 	ad_net_init_from_iif(&ad, &net, ifindex, family);
5744 	if (selinux_parse_skb(skb, &ad, &addrp, 1, NULL) != 0)
5745 		return NF_DROP;
5746 
5747 	if (peerlbl_active) {
5748 		int err;
5749 
5750 		err = selinux_inet_sys_rcv_skb(state->net, ifindex,
5751 					       addrp, family, peer_sid, &ad);
5752 		if (err) {
5753 			selinux_netlbl_err(skb, family, err, 1);
5754 			return NF_DROP;
5755 		}
5756 	}
5757 
5758 	if (secmark_active)
5759 		if (avc_has_perm(peer_sid, skb->secmark,
5760 				 SECCLASS_PACKET, PACKET__FORWARD_IN, &ad))
5761 			return NF_DROP;
5762 
5763 	if (netlbl_enabled())
5764 		/* we do this in the FORWARD path and not the POST_ROUTING
5765 		 * path because we want to make sure we apply the necessary
5766 		 * labeling before IPsec is applied so we can leverage AH
5767 		 * protection */
5768 		if (selinux_netlbl_skbuff_setsid(skb, family, peer_sid) != 0)
5769 			return NF_DROP;
5770 
5771 	return NF_ACCEPT;
5772 }
5773 
selinux_ip_output(void * priv,struct sk_buff * skb,const struct nf_hook_state * state)5774 static unsigned int selinux_ip_output(void *priv, struct sk_buff *skb,
5775 				      const struct nf_hook_state *state)
5776 {
5777 	struct sock *sk;
5778 	u32 sid;
5779 
5780 	if (!netlbl_enabled())
5781 		return NF_ACCEPT;
5782 
5783 	/* we do this in the LOCAL_OUT path and not the POST_ROUTING path
5784 	 * because we want to make sure we apply the necessary labeling
5785 	 * before IPsec is applied so we can leverage AH protection */
5786 	sk = sk_to_full_sk(skb->sk);
5787 	if (sk) {
5788 		struct sk_security_struct *sksec;
5789 
5790 		if (sk_listener(sk))
5791 			/* if the socket is the listening state then this
5792 			 * packet is a SYN-ACK packet which means it needs to
5793 			 * be labeled based on the connection/request_sock and
5794 			 * not the parent socket.  unfortunately, we can't
5795 			 * lookup the request_sock yet as it isn't queued on
5796 			 * the parent socket until after the SYN-ACK is sent.
5797 			 * the "solution" is to simply pass the packet as-is
5798 			 * as any IP option based labeling should be copied
5799 			 * from the initial connection request (in the IP
5800 			 * layer).  it is far from ideal, but until we get a
5801 			 * security label in the packet itself this is the
5802 			 * best we can do. */
5803 			return NF_ACCEPT;
5804 
5805 		/* standard practice, label using the parent socket */
5806 		sksec = selinux_sock(sk);
5807 		sid = sksec->sid;
5808 	} else
5809 		sid = SECINITSID_KERNEL;
5810 	if (selinux_netlbl_skbuff_setsid(skb, state->pf, sid) != 0)
5811 		return NF_DROP;
5812 
5813 	return NF_ACCEPT;
5814 }
5815 
5816 
selinux_ip_postroute_compat(struct sk_buff * skb,const struct nf_hook_state * state)5817 static unsigned int selinux_ip_postroute_compat(struct sk_buff *skb,
5818 					const struct nf_hook_state *state)
5819 {
5820 	struct sock *sk;
5821 	struct sk_security_struct *sksec;
5822 	struct common_audit_data ad;
5823 	struct lsm_network_audit net;
5824 	u8 proto = 0;
5825 
5826 	sk = skb_to_full_sk(skb);
5827 	if (sk == NULL)
5828 		return NF_ACCEPT;
5829 	sksec = selinux_sock(sk);
5830 
5831 	ad_net_init_from_iif(&ad, &net, state->out->ifindex, state->pf);
5832 	if (selinux_parse_skb(skb, &ad, NULL, 0, &proto))
5833 		return NF_DROP;
5834 
5835 	if (selinux_secmark_enabled())
5836 		if (avc_has_perm(sksec->sid, skb->secmark,
5837 				 SECCLASS_PACKET, PACKET__SEND, &ad))
5838 			return NF_DROP_ERR(-ECONNREFUSED);
5839 
5840 	if (selinux_xfrm_postroute_last(sksec->sid, skb, &ad, proto))
5841 		return NF_DROP_ERR(-ECONNREFUSED);
5842 
5843 	return NF_ACCEPT;
5844 }
5845 
selinux_ip_postroute(void * priv,struct sk_buff * skb,const struct nf_hook_state * state)5846 static unsigned int selinux_ip_postroute(void *priv,
5847 					 struct sk_buff *skb,
5848 					 const struct nf_hook_state *state)
5849 {
5850 	u16 family;
5851 	u32 secmark_perm;
5852 	u32 peer_sid;
5853 	int ifindex;
5854 	struct sock *sk;
5855 	struct common_audit_data ad;
5856 	struct lsm_network_audit net;
5857 	char *addrp;
5858 	int secmark_active, peerlbl_active;
5859 
5860 	/* If any sort of compatibility mode is enabled then handoff processing
5861 	 * to the selinux_ip_postroute_compat() function to deal with the
5862 	 * special handling.  We do this in an attempt to keep this function
5863 	 * as fast and as clean as possible. */
5864 	if (!selinux_policycap_netpeer())
5865 		return selinux_ip_postroute_compat(skb, state);
5866 
5867 	secmark_active = selinux_secmark_enabled();
5868 	peerlbl_active = selinux_peerlbl_enabled();
5869 	if (!secmark_active && !peerlbl_active)
5870 		return NF_ACCEPT;
5871 
5872 	sk = skb_to_full_sk(skb);
5873 
5874 #ifdef CONFIG_XFRM
5875 	/* If skb->dst->xfrm is non-NULL then the packet is undergoing an IPsec
5876 	 * packet transformation so allow the packet to pass without any checks
5877 	 * since we'll have another chance to perform access control checks
5878 	 * when the packet is on it's final way out.
5879 	 * NOTE: there appear to be some IPv6 multicast cases where skb->dst
5880 	 *       is NULL, in this case go ahead and apply access control.
5881 	 * NOTE: if this is a local socket (skb->sk != NULL) that is in the
5882 	 *       TCP listening state we cannot wait until the XFRM processing
5883 	 *       is done as we will miss out on the SA label if we do;
5884 	 *       unfortunately, this means more work, but it is only once per
5885 	 *       connection. */
5886 	if (skb_dst(skb) != NULL && skb_dst(skb)->xfrm != NULL &&
5887 	    !(sk && sk_listener(sk)))
5888 		return NF_ACCEPT;
5889 #endif
5890 
5891 	family = state->pf;
5892 	if (sk == NULL) {
5893 		/* Without an associated socket the packet is either coming
5894 		 * from the kernel or it is being forwarded; check the packet
5895 		 * to determine which and if the packet is being forwarded
5896 		 * query the packet directly to determine the security label. */
5897 		if (skb->skb_iif) {
5898 			secmark_perm = PACKET__FORWARD_OUT;
5899 			if (selinux_skb_peerlbl_sid(skb, family, &peer_sid))
5900 				return NF_DROP;
5901 		} else {
5902 			secmark_perm = PACKET__SEND;
5903 			peer_sid = SECINITSID_KERNEL;
5904 		}
5905 	} else if (sk_listener(sk)) {
5906 		/* Locally generated packet but the associated socket is in the
5907 		 * listening state which means this is a SYN-ACK packet.  In
5908 		 * this particular case the correct security label is assigned
5909 		 * to the connection/request_sock but unfortunately we can't
5910 		 * query the request_sock as it isn't queued on the parent
5911 		 * socket until after the SYN-ACK packet is sent; the only
5912 		 * viable choice is to regenerate the label like we do in
5913 		 * selinux_inet_conn_request().  See also selinux_ip_output()
5914 		 * for similar problems. */
5915 		u32 skb_sid;
5916 		struct sk_security_struct *sksec;
5917 
5918 		sksec = selinux_sock(sk);
5919 		if (selinux_skb_peerlbl_sid(skb, family, &skb_sid))
5920 			return NF_DROP;
5921 		/* At this point, if the returned skb peerlbl is SECSID_NULL
5922 		 * and the packet has been through at least one XFRM
5923 		 * transformation then we must be dealing with the "final"
5924 		 * form of labeled IPsec packet; since we've already applied
5925 		 * all of our access controls on this packet we can safely
5926 		 * pass the packet. */
5927 		if (skb_sid == SECSID_NULL) {
5928 			switch (family) {
5929 			case PF_INET:
5930 				if (IPCB(skb)->flags & IPSKB_XFRM_TRANSFORMED)
5931 					return NF_ACCEPT;
5932 				break;
5933 			case PF_INET6:
5934 				if (IP6CB(skb)->flags & IP6SKB_XFRM_TRANSFORMED)
5935 					return NF_ACCEPT;
5936 				break;
5937 			default:
5938 				return NF_DROP_ERR(-ECONNREFUSED);
5939 			}
5940 		}
5941 		if (selinux_conn_sid(sksec->sid, skb_sid, &peer_sid))
5942 			return NF_DROP;
5943 		secmark_perm = PACKET__SEND;
5944 	} else {
5945 		/* Locally generated packet, fetch the security label from the
5946 		 * associated socket. */
5947 		struct sk_security_struct *sksec = selinux_sock(sk);
5948 		peer_sid = sksec->sid;
5949 		secmark_perm = PACKET__SEND;
5950 	}
5951 
5952 	ifindex = state->out->ifindex;
5953 	ad_net_init_from_iif(&ad, &net, ifindex, family);
5954 	if (selinux_parse_skb(skb, &ad, &addrp, 0, NULL))
5955 		return NF_DROP;
5956 
5957 	if (secmark_active)
5958 		if (avc_has_perm(peer_sid, skb->secmark,
5959 				 SECCLASS_PACKET, secmark_perm, &ad))
5960 			return NF_DROP_ERR(-ECONNREFUSED);
5961 
5962 	if (peerlbl_active) {
5963 		u32 if_sid;
5964 		u32 node_sid;
5965 
5966 		if (sel_netif_sid(state->net, ifindex, &if_sid))
5967 			return NF_DROP;
5968 		if (avc_has_perm(peer_sid, if_sid,
5969 				 SECCLASS_NETIF, NETIF__EGRESS, &ad))
5970 			return NF_DROP_ERR(-ECONNREFUSED);
5971 
5972 		if (sel_netnode_sid(addrp, family, &node_sid))
5973 			return NF_DROP;
5974 		if (avc_has_perm(peer_sid, node_sid,
5975 				 SECCLASS_NODE, NODE__SENDTO, &ad))
5976 			return NF_DROP_ERR(-ECONNREFUSED);
5977 	}
5978 
5979 	return NF_ACCEPT;
5980 }
5981 #endif	/* CONFIG_NETFILTER */
5982 
nlmsg_sock_has_extended_perms(struct sock * sk,u32 perms,u16 nlmsg_type)5983 static int nlmsg_sock_has_extended_perms(struct sock *sk, u32 perms, u16 nlmsg_type)
5984 {
5985 	struct sk_security_struct *sksec = sk->sk_security;
5986 	struct common_audit_data ad;
5987 	u8 driver;
5988 	u8 xperm;
5989 
5990 	if (sock_skip_has_perm(sksec->sid))
5991 		return 0;
5992 
5993 	ad.type = LSM_AUDIT_DATA_NLMSGTYPE;
5994 	ad.u.nlmsg_type = nlmsg_type;
5995 
5996 	driver = nlmsg_type >> 8;
5997 	xperm = nlmsg_type & 0xff;
5998 
5999 	return avc_has_extended_perms(current_sid(), sksec->sid, sksec->sclass,
6000 				      perms, driver, AVC_EXT_NLMSG, xperm, &ad);
6001 }
6002 
selinux_netlink_send(struct sock * sk,struct sk_buff * skb)6003 static int selinux_netlink_send(struct sock *sk, struct sk_buff *skb)
6004 {
6005 	int rc = 0;
6006 	unsigned int msg_len;
6007 	unsigned int data_len = skb->len;
6008 	unsigned char *data = skb->data;
6009 	struct nlmsghdr *nlh;
6010 	struct sk_security_struct *sksec = selinux_sock(sk);
6011 	u16 sclass = sksec->sclass;
6012 	u32 perm;
6013 
6014 	while (data_len >= nlmsg_total_size(0)) {
6015 		nlh = (struct nlmsghdr *)data;
6016 
6017 		/* NOTE: the nlmsg_len field isn't reliably set by some netlink
6018 		 *       users which means we can't reject skb's with bogus
6019 		 *       length fields; our solution is to follow what
6020 		 *       netlink_rcv_skb() does and simply skip processing at
6021 		 *       messages with length fields that are clearly junk
6022 		 */
6023 		if (nlh->nlmsg_len < NLMSG_HDRLEN || nlh->nlmsg_len > data_len)
6024 			return 0;
6025 
6026 		rc = selinux_nlmsg_lookup(sclass, nlh->nlmsg_type, &perm);
6027 		if (rc == 0) {
6028 			if (selinux_policycap_netlink_xperm()) {
6029 				rc = nlmsg_sock_has_extended_perms(
6030 					sk, perm, nlh->nlmsg_type);
6031 			} else {
6032 				rc = sock_has_perm(sk, perm);
6033 			}
6034 			if (rc)
6035 				return rc;
6036 		} else if (rc == -EINVAL) {
6037 			/* -EINVAL is a missing msg/perm mapping */
6038 			pr_warn_ratelimited("SELinux: unrecognized netlink"
6039 				" message: protocol=%hu nlmsg_type=%hu sclass=%s"
6040 				" pid=%d comm=%s\n",
6041 				sk->sk_protocol, nlh->nlmsg_type,
6042 				secclass_map[sclass - 1].name,
6043 				task_pid_nr(current), current->comm);
6044 			if (enforcing_enabled() &&
6045 			    !security_get_allow_unknown())
6046 				return rc;
6047 			rc = 0;
6048 		} else if (rc == -ENOENT) {
6049 			/* -ENOENT is a missing socket/class mapping, ignore */
6050 			rc = 0;
6051 		} else {
6052 			return rc;
6053 		}
6054 
6055 		/* move to the next message after applying netlink padding */
6056 		msg_len = NLMSG_ALIGN(nlh->nlmsg_len);
6057 		if (msg_len >= data_len)
6058 			return 0;
6059 		data_len -= msg_len;
6060 		data += msg_len;
6061 	}
6062 
6063 	return rc;
6064 }
6065 
ipc_init_security(struct ipc_security_struct * isec,u16 sclass)6066 static void ipc_init_security(struct ipc_security_struct *isec, u16 sclass)
6067 {
6068 	isec->sclass = sclass;
6069 	isec->sid = current_sid();
6070 }
6071 
ipc_has_perm(struct kern_ipc_perm * ipc_perms,u32 perms)6072 static int ipc_has_perm(struct kern_ipc_perm *ipc_perms,
6073 			u32 perms)
6074 {
6075 	struct ipc_security_struct *isec;
6076 	struct common_audit_data ad;
6077 	u32 sid = current_sid();
6078 
6079 	isec = selinux_ipc(ipc_perms);
6080 
6081 	ad.type = LSM_AUDIT_DATA_IPC;
6082 	ad.u.ipc_id = ipc_perms->key;
6083 
6084 	return avc_has_perm(sid, isec->sid, isec->sclass, perms, &ad);
6085 }
6086 
selinux_msg_msg_alloc_security(struct msg_msg * msg)6087 static int selinux_msg_msg_alloc_security(struct msg_msg *msg)
6088 {
6089 	struct msg_security_struct *msec;
6090 
6091 	msec = selinux_msg_msg(msg);
6092 	msec->sid = SECINITSID_UNLABELED;
6093 
6094 	return 0;
6095 }
6096 
6097 /* message queue security operations */
selinux_msg_queue_alloc_security(struct kern_ipc_perm * msq)6098 static int selinux_msg_queue_alloc_security(struct kern_ipc_perm *msq)
6099 {
6100 	struct ipc_security_struct *isec;
6101 	struct common_audit_data ad;
6102 	u32 sid = current_sid();
6103 
6104 	isec = selinux_ipc(msq);
6105 	ipc_init_security(isec, SECCLASS_MSGQ);
6106 
6107 	ad.type = LSM_AUDIT_DATA_IPC;
6108 	ad.u.ipc_id = msq->key;
6109 
6110 	return avc_has_perm(sid, isec->sid, SECCLASS_MSGQ,
6111 			    MSGQ__CREATE, &ad);
6112 }
6113 
selinux_msg_queue_associate(struct kern_ipc_perm * msq,int msqflg)6114 static int selinux_msg_queue_associate(struct kern_ipc_perm *msq, int msqflg)
6115 {
6116 	struct ipc_security_struct *isec;
6117 	struct common_audit_data ad;
6118 	u32 sid = current_sid();
6119 
6120 	isec = selinux_ipc(msq);
6121 
6122 	ad.type = LSM_AUDIT_DATA_IPC;
6123 	ad.u.ipc_id = msq->key;
6124 
6125 	return avc_has_perm(sid, isec->sid, SECCLASS_MSGQ,
6126 			    MSGQ__ASSOCIATE, &ad);
6127 }
6128 
selinux_msg_queue_msgctl(struct kern_ipc_perm * msq,int cmd)6129 static int selinux_msg_queue_msgctl(struct kern_ipc_perm *msq, int cmd)
6130 {
6131 	u32 perms;
6132 
6133 	switch (cmd) {
6134 	case IPC_INFO:
6135 	case MSG_INFO:
6136 		/* No specific object, just general system-wide information. */
6137 		return avc_has_perm(current_sid(), SECINITSID_KERNEL,
6138 				    SECCLASS_SYSTEM, SYSTEM__IPC_INFO, NULL);
6139 	case IPC_STAT:
6140 	case MSG_STAT:
6141 	case MSG_STAT_ANY:
6142 		perms = MSGQ__GETATTR | MSGQ__ASSOCIATE;
6143 		break;
6144 	case IPC_SET:
6145 		perms = MSGQ__SETATTR;
6146 		break;
6147 	case IPC_RMID:
6148 		perms = MSGQ__DESTROY;
6149 		break;
6150 	default:
6151 		return 0;
6152 	}
6153 
6154 	return ipc_has_perm(msq, perms);
6155 }
6156 
selinux_msg_queue_msgsnd(struct kern_ipc_perm * msq,struct msg_msg * msg,int msqflg)6157 static int selinux_msg_queue_msgsnd(struct kern_ipc_perm *msq, struct msg_msg *msg, int msqflg)
6158 {
6159 	struct ipc_security_struct *isec;
6160 	struct msg_security_struct *msec;
6161 	struct common_audit_data ad;
6162 	u32 sid = current_sid();
6163 	int rc;
6164 
6165 	isec = selinux_ipc(msq);
6166 	msec = selinux_msg_msg(msg);
6167 
6168 	/*
6169 	 * First time through, need to assign label to the message
6170 	 */
6171 	if (msec->sid == SECINITSID_UNLABELED) {
6172 		/*
6173 		 * Compute new sid based on current process and
6174 		 * message queue this message will be stored in
6175 		 */
6176 		rc = security_transition_sid(sid, isec->sid,
6177 					     SECCLASS_MSG, NULL, &msec->sid);
6178 		if (rc)
6179 			return rc;
6180 	}
6181 
6182 	ad.type = LSM_AUDIT_DATA_IPC;
6183 	ad.u.ipc_id = msq->key;
6184 
6185 	/* Can this process write to the queue? */
6186 	rc = avc_has_perm(sid, isec->sid, SECCLASS_MSGQ,
6187 			  MSGQ__WRITE, &ad);
6188 	if (!rc)
6189 		/* Can this process send the message */
6190 		rc = avc_has_perm(sid, msec->sid, SECCLASS_MSG,
6191 				  MSG__SEND, &ad);
6192 	if (!rc)
6193 		/* Can the message be put in the queue? */
6194 		rc = avc_has_perm(msec->sid, isec->sid, SECCLASS_MSGQ,
6195 				  MSGQ__ENQUEUE, &ad);
6196 
6197 	return rc;
6198 }
6199 
selinux_msg_queue_msgrcv(struct kern_ipc_perm * msq,struct msg_msg * msg,struct task_struct * target,long type,int mode)6200 static int selinux_msg_queue_msgrcv(struct kern_ipc_perm *msq, struct msg_msg *msg,
6201 				    struct task_struct *target,
6202 				    long type, int mode)
6203 {
6204 	struct ipc_security_struct *isec;
6205 	struct msg_security_struct *msec;
6206 	struct common_audit_data ad;
6207 	u32 sid = task_sid_obj(target);
6208 	int rc;
6209 
6210 	isec = selinux_ipc(msq);
6211 	msec = selinux_msg_msg(msg);
6212 
6213 	ad.type = LSM_AUDIT_DATA_IPC;
6214 	ad.u.ipc_id = msq->key;
6215 
6216 	rc = avc_has_perm(sid, isec->sid,
6217 			  SECCLASS_MSGQ, MSGQ__READ, &ad);
6218 	if (!rc)
6219 		rc = avc_has_perm(sid, msec->sid,
6220 				  SECCLASS_MSG, MSG__RECEIVE, &ad);
6221 	return rc;
6222 }
6223 
6224 /* Shared Memory security operations */
selinux_shm_alloc_security(struct kern_ipc_perm * shp)6225 static int selinux_shm_alloc_security(struct kern_ipc_perm *shp)
6226 {
6227 	struct ipc_security_struct *isec;
6228 	struct common_audit_data ad;
6229 	u32 sid = current_sid();
6230 
6231 	isec = selinux_ipc(shp);
6232 	ipc_init_security(isec, SECCLASS_SHM);
6233 
6234 	ad.type = LSM_AUDIT_DATA_IPC;
6235 	ad.u.ipc_id = shp->key;
6236 
6237 	return avc_has_perm(sid, isec->sid, SECCLASS_SHM,
6238 			    SHM__CREATE, &ad);
6239 }
6240 
selinux_shm_associate(struct kern_ipc_perm * shp,int shmflg)6241 static int selinux_shm_associate(struct kern_ipc_perm *shp, int shmflg)
6242 {
6243 	struct ipc_security_struct *isec;
6244 	struct common_audit_data ad;
6245 	u32 sid = current_sid();
6246 
6247 	isec = selinux_ipc(shp);
6248 
6249 	ad.type = LSM_AUDIT_DATA_IPC;
6250 	ad.u.ipc_id = shp->key;
6251 
6252 	return avc_has_perm(sid, isec->sid, SECCLASS_SHM,
6253 			    SHM__ASSOCIATE, &ad);
6254 }
6255 
6256 /* Note, at this point, shp is locked down */
selinux_shm_shmctl(struct kern_ipc_perm * shp,int cmd)6257 static int selinux_shm_shmctl(struct kern_ipc_perm *shp, int cmd)
6258 {
6259 	u32 perms;
6260 
6261 	switch (cmd) {
6262 	case IPC_INFO:
6263 	case SHM_INFO:
6264 		/* No specific object, just general system-wide information. */
6265 		return avc_has_perm(current_sid(), SECINITSID_KERNEL,
6266 				    SECCLASS_SYSTEM, SYSTEM__IPC_INFO, NULL);
6267 	case IPC_STAT:
6268 	case SHM_STAT:
6269 	case SHM_STAT_ANY:
6270 		perms = SHM__GETATTR | SHM__ASSOCIATE;
6271 		break;
6272 	case IPC_SET:
6273 		perms = SHM__SETATTR;
6274 		break;
6275 	case SHM_LOCK:
6276 	case SHM_UNLOCK:
6277 		perms = SHM__LOCK;
6278 		break;
6279 	case IPC_RMID:
6280 		perms = SHM__DESTROY;
6281 		break;
6282 	default:
6283 		return 0;
6284 	}
6285 
6286 	return ipc_has_perm(shp, perms);
6287 }
6288 
selinux_shm_shmat(struct kern_ipc_perm * shp,char __user * shmaddr,int shmflg)6289 static int selinux_shm_shmat(struct kern_ipc_perm *shp,
6290 			     char __user *shmaddr, int shmflg)
6291 {
6292 	u32 perms;
6293 
6294 	if (shmflg & SHM_RDONLY)
6295 		perms = SHM__READ;
6296 	else
6297 		perms = SHM__READ | SHM__WRITE;
6298 
6299 	return ipc_has_perm(shp, perms);
6300 }
6301 
6302 /* Semaphore security operations */
selinux_sem_alloc_security(struct kern_ipc_perm * sma)6303 static int selinux_sem_alloc_security(struct kern_ipc_perm *sma)
6304 {
6305 	struct ipc_security_struct *isec;
6306 	struct common_audit_data ad;
6307 	u32 sid = current_sid();
6308 
6309 	isec = selinux_ipc(sma);
6310 	ipc_init_security(isec, SECCLASS_SEM);
6311 
6312 	ad.type = LSM_AUDIT_DATA_IPC;
6313 	ad.u.ipc_id = sma->key;
6314 
6315 	return avc_has_perm(sid, isec->sid, SECCLASS_SEM,
6316 			    SEM__CREATE, &ad);
6317 }
6318 
selinux_sem_associate(struct kern_ipc_perm * sma,int semflg)6319 static int selinux_sem_associate(struct kern_ipc_perm *sma, int semflg)
6320 {
6321 	struct ipc_security_struct *isec;
6322 	struct common_audit_data ad;
6323 	u32 sid = current_sid();
6324 
6325 	isec = selinux_ipc(sma);
6326 
6327 	ad.type = LSM_AUDIT_DATA_IPC;
6328 	ad.u.ipc_id = sma->key;
6329 
6330 	return avc_has_perm(sid, isec->sid, SECCLASS_SEM,
6331 			    SEM__ASSOCIATE, &ad);
6332 }
6333 
6334 /* Note, at this point, sma is locked down */
selinux_sem_semctl(struct kern_ipc_perm * sma,int cmd)6335 static int selinux_sem_semctl(struct kern_ipc_perm *sma, int cmd)
6336 {
6337 	int err;
6338 	u32 perms;
6339 
6340 	switch (cmd) {
6341 	case IPC_INFO:
6342 	case SEM_INFO:
6343 		/* No specific object, just general system-wide information. */
6344 		return avc_has_perm(current_sid(), SECINITSID_KERNEL,
6345 				    SECCLASS_SYSTEM, SYSTEM__IPC_INFO, NULL);
6346 	case GETPID:
6347 	case GETNCNT:
6348 	case GETZCNT:
6349 		perms = SEM__GETATTR;
6350 		break;
6351 	case GETVAL:
6352 	case GETALL:
6353 		perms = SEM__READ;
6354 		break;
6355 	case SETVAL:
6356 	case SETALL:
6357 		perms = SEM__WRITE;
6358 		break;
6359 	case IPC_RMID:
6360 		perms = SEM__DESTROY;
6361 		break;
6362 	case IPC_SET:
6363 		perms = SEM__SETATTR;
6364 		break;
6365 	case IPC_STAT:
6366 	case SEM_STAT:
6367 	case SEM_STAT_ANY:
6368 		perms = SEM__GETATTR | SEM__ASSOCIATE;
6369 		break;
6370 	default:
6371 		return 0;
6372 	}
6373 
6374 	err = ipc_has_perm(sma, perms);
6375 	return err;
6376 }
6377 
selinux_sem_semop(struct kern_ipc_perm * sma,struct sembuf * sops,unsigned nsops,int alter)6378 static int selinux_sem_semop(struct kern_ipc_perm *sma,
6379 			     struct sembuf *sops, unsigned nsops, int alter)
6380 {
6381 	u32 perms;
6382 
6383 	if (alter)
6384 		perms = SEM__READ | SEM__WRITE;
6385 	else
6386 		perms = SEM__READ;
6387 
6388 	return ipc_has_perm(sma, perms);
6389 }
6390 
selinux_ipc_permission(struct kern_ipc_perm * ipcp,short flag)6391 static int selinux_ipc_permission(struct kern_ipc_perm *ipcp, short flag)
6392 {
6393 	u32 av = 0;
6394 
6395 	av = 0;
6396 	if (flag & S_IRUGO)
6397 		av |= IPC__UNIX_READ;
6398 	if (flag & S_IWUGO)
6399 		av |= IPC__UNIX_WRITE;
6400 
6401 	if (av == 0)
6402 		return 0;
6403 
6404 	return ipc_has_perm(ipcp, av);
6405 }
6406 
selinux_ipc_getlsmprop(struct kern_ipc_perm * ipcp,struct lsm_prop * prop)6407 static void selinux_ipc_getlsmprop(struct kern_ipc_perm *ipcp,
6408 				   struct lsm_prop *prop)
6409 {
6410 	struct ipc_security_struct *isec = selinux_ipc(ipcp);
6411 	prop->selinux.secid = isec->sid;
6412 }
6413 
selinux_d_instantiate(struct dentry * dentry,struct inode * inode)6414 static void selinux_d_instantiate(struct dentry *dentry, struct inode *inode)
6415 {
6416 	if (inode)
6417 		inode_doinit_with_dentry(inode, dentry);
6418 }
6419 
selinux_lsm_getattr(unsigned int attr,struct task_struct * p,char ** value)6420 static int selinux_lsm_getattr(unsigned int attr, struct task_struct *p,
6421 			       char **value)
6422 {
6423 	const struct task_security_struct *tsec;
6424 	int error;
6425 	u32 sid;
6426 	u32 len;
6427 
6428 	rcu_read_lock();
6429 	tsec = selinux_cred(__task_cred(p));
6430 	if (p != current) {
6431 		error = avc_has_perm(current_sid(), tsec->sid,
6432 				     SECCLASS_PROCESS, PROCESS__GETATTR, NULL);
6433 		if (error)
6434 			goto err_unlock;
6435 	}
6436 	switch (attr) {
6437 	case LSM_ATTR_CURRENT:
6438 		sid = tsec->sid;
6439 		break;
6440 	case LSM_ATTR_PREV:
6441 		sid = tsec->osid;
6442 		break;
6443 	case LSM_ATTR_EXEC:
6444 		sid = tsec->exec_sid;
6445 		break;
6446 	case LSM_ATTR_FSCREATE:
6447 		sid = tsec->create_sid;
6448 		break;
6449 	case LSM_ATTR_KEYCREATE:
6450 		sid = tsec->keycreate_sid;
6451 		break;
6452 	case LSM_ATTR_SOCKCREATE:
6453 		sid = tsec->sockcreate_sid;
6454 		break;
6455 	default:
6456 		error = -EOPNOTSUPP;
6457 		goto err_unlock;
6458 	}
6459 	rcu_read_unlock();
6460 
6461 	if (sid == SECSID_NULL) {
6462 		*value = NULL;
6463 		return 0;
6464 	}
6465 
6466 	error = security_sid_to_context(sid, value, &len);
6467 	if (error)
6468 		return error;
6469 	return len;
6470 
6471 err_unlock:
6472 	rcu_read_unlock();
6473 	return error;
6474 }
6475 
selinux_lsm_setattr(u64 attr,void * value,size_t size)6476 static int selinux_lsm_setattr(u64 attr, void *value, size_t size)
6477 {
6478 	struct task_security_struct *tsec;
6479 	struct cred *new;
6480 	u32 mysid = current_sid(), sid = 0, ptsid;
6481 	int error;
6482 	char *str = value;
6483 
6484 	/*
6485 	 * Basic control over ability to set these attributes at all.
6486 	 */
6487 	switch (attr) {
6488 	case LSM_ATTR_EXEC:
6489 		error = avc_has_perm(mysid, mysid, SECCLASS_PROCESS,
6490 				     PROCESS__SETEXEC, NULL);
6491 		break;
6492 	case LSM_ATTR_FSCREATE:
6493 		error = avc_has_perm(mysid, mysid, SECCLASS_PROCESS,
6494 				     PROCESS__SETFSCREATE, NULL);
6495 		break;
6496 	case LSM_ATTR_KEYCREATE:
6497 		error = avc_has_perm(mysid, mysid, SECCLASS_PROCESS,
6498 				     PROCESS__SETKEYCREATE, NULL);
6499 		break;
6500 	case LSM_ATTR_SOCKCREATE:
6501 		error = avc_has_perm(mysid, mysid, SECCLASS_PROCESS,
6502 				     PROCESS__SETSOCKCREATE, NULL);
6503 		break;
6504 	case LSM_ATTR_CURRENT:
6505 		error = avc_has_perm(mysid, mysid, SECCLASS_PROCESS,
6506 				     PROCESS__SETCURRENT, NULL);
6507 		break;
6508 	default:
6509 		error = -EOPNOTSUPP;
6510 		break;
6511 	}
6512 	if (error)
6513 		return error;
6514 
6515 	/* Obtain a SID for the context, if one was specified. */
6516 	if (size && str[0] && str[0] != '\n') {
6517 		if (str[size-1] == '\n') {
6518 			str[size-1] = 0;
6519 			size--;
6520 		}
6521 		error = security_context_to_sid(value, size,
6522 						&sid, GFP_KERNEL);
6523 		if (error == -EINVAL && attr == LSM_ATTR_FSCREATE) {
6524 			if (!has_cap_mac_admin(true)) {
6525 				struct audit_buffer *ab;
6526 				size_t audit_size;
6527 
6528 				/* We strip a nul only if it is at the end,
6529 				 * otherwise the context contains a nul and
6530 				 * we should audit that */
6531 				if (str[size - 1] == '\0')
6532 					audit_size = size - 1;
6533 				else
6534 					audit_size = size;
6535 				ab = audit_log_start(audit_context(),
6536 						     GFP_ATOMIC,
6537 						     AUDIT_SELINUX_ERR);
6538 				if (!ab)
6539 					return error;
6540 				audit_log_format(ab, "op=fscreate invalid_context=");
6541 				audit_log_n_untrustedstring(ab, value,
6542 							    audit_size);
6543 				audit_log_end(ab);
6544 
6545 				return error;
6546 			}
6547 			error = security_context_to_sid_force(value, size,
6548 							&sid);
6549 		}
6550 		if (error)
6551 			return error;
6552 	}
6553 
6554 	new = prepare_creds();
6555 	if (!new)
6556 		return -ENOMEM;
6557 
6558 	/* Permission checking based on the specified context is
6559 	   performed during the actual operation (execve,
6560 	   open/mkdir/...), when we know the full context of the
6561 	   operation.  See selinux_bprm_creds_for_exec for the execve
6562 	   checks and may_create for the file creation checks. The
6563 	   operation will then fail if the context is not permitted. */
6564 	tsec = selinux_cred(new);
6565 	if (attr == LSM_ATTR_EXEC) {
6566 		tsec->exec_sid = sid;
6567 	} else if (attr == LSM_ATTR_FSCREATE) {
6568 		tsec->create_sid = sid;
6569 	} else if (attr == LSM_ATTR_KEYCREATE) {
6570 		if (sid) {
6571 			error = avc_has_perm(mysid, sid,
6572 					     SECCLASS_KEY, KEY__CREATE, NULL);
6573 			if (error)
6574 				goto abort_change;
6575 		}
6576 		tsec->keycreate_sid = sid;
6577 	} else if (attr == LSM_ATTR_SOCKCREATE) {
6578 		tsec->sockcreate_sid = sid;
6579 	} else if (attr == LSM_ATTR_CURRENT) {
6580 		error = -EINVAL;
6581 		if (sid == 0)
6582 			goto abort_change;
6583 
6584 		if (!current_is_single_threaded()) {
6585 			error = security_bounded_transition(tsec->sid, sid);
6586 			if (error)
6587 				goto abort_change;
6588 		}
6589 
6590 		/* Check permissions for the transition. */
6591 		error = avc_has_perm(tsec->sid, sid, SECCLASS_PROCESS,
6592 				     PROCESS__DYNTRANSITION, NULL);
6593 		if (error)
6594 			goto abort_change;
6595 
6596 		/* Check for ptracing, and update the task SID if ok.
6597 		   Otherwise, leave SID unchanged and fail. */
6598 		ptsid = ptrace_parent_sid();
6599 		if (ptsid != 0) {
6600 			error = avc_has_perm(ptsid, sid, SECCLASS_PROCESS,
6601 					     PROCESS__PTRACE, NULL);
6602 			if (error)
6603 				goto abort_change;
6604 		}
6605 
6606 		tsec->sid = sid;
6607 	} else {
6608 		error = -EINVAL;
6609 		goto abort_change;
6610 	}
6611 
6612 	commit_creds(new);
6613 	return size;
6614 
6615 abort_change:
6616 	abort_creds(new);
6617 	return error;
6618 }
6619 
6620 /**
6621  * selinux_getselfattr - Get SELinux current task attributes
6622  * @attr: the requested attribute
6623  * @ctx: buffer to receive the result
6624  * @size: buffer size (input), buffer size used (output)
6625  * @flags: unused
6626  *
6627  * Fill the passed user space @ctx with the details of the requested
6628  * attribute.
6629  *
6630  * Returns the number of attributes on success, an error code otherwise.
6631  * There will only ever be one attribute.
6632  */
selinux_getselfattr(unsigned int attr,struct lsm_ctx __user * ctx,u32 * size,u32 flags)6633 static int selinux_getselfattr(unsigned int attr, struct lsm_ctx __user *ctx,
6634 			       u32 *size, u32 flags)
6635 {
6636 	int rc;
6637 	char *val = NULL;
6638 	int val_len;
6639 
6640 	val_len = selinux_lsm_getattr(attr, current, &val);
6641 	if (val_len < 0)
6642 		return val_len;
6643 	rc = lsm_fill_user_ctx(ctx, size, val, val_len, LSM_ID_SELINUX, 0);
6644 	kfree(val);
6645 	return (!rc ? 1 : rc);
6646 }
6647 
selinux_setselfattr(unsigned int attr,struct lsm_ctx * ctx,u32 size,u32 flags)6648 static int selinux_setselfattr(unsigned int attr, struct lsm_ctx *ctx,
6649 			       u32 size, u32 flags)
6650 {
6651 	int rc;
6652 
6653 	rc = selinux_lsm_setattr(attr, ctx->ctx, ctx->ctx_len);
6654 	if (rc > 0)
6655 		return 0;
6656 	return rc;
6657 }
6658 
selinux_getprocattr(struct task_struct * p,const char * name,char ** value)6659 static int selinux_getprocattr(struct task_struct *p,
6660 			       const char *name, char **value)
6661 {
6662 	unsigned int attr = lsm_name_to_attr(name);
6663 	int rc;
6664 
6665 	if (attr) {
6666 		rc = selinux_lsm_getattr(attr, p, value);
6667 		if (rc != -EOPNOTSUPP)
6668 			return rc;
6669 	}
6670 
6671 	return -EINVAL;
6672 }
6673 
selinux_setprocattr(const char * name,void * value,size_t size)6674 static int selinux_setprocattr(const char *name, void *value, size_t size)
6675 {
6676 	int attr = lsm_name_to_attr(name);
6677 
6678 	if (attr)
6679 		return selinux_lsm_setattr(attr, value, size);
6680 	return -EINVAL;
6681 }
6682 
selinux_ismaclabel(const char * name)6683 static int selinux_ismaclabel(const char *name)
6684 {
6685 	return (strcmp(name, XATTR_SELINUX_SUFFIX) == 0);
6686 }
6687 
selinux_secid_to_secctx(u32 secid,struct lsm_context * cp)6688 static int selinux_secid_to_secctx(u32 secid, struct lsm_context *cp)
6689 {
6690 	u32 seclen;
6691 	int ret;
6692 
6693 	if (cp) {
6694 		cp->id = LSM_ID_SELINUX;
6695 		ret = security_sid_to_context(secid, &cp->context, &cp->len);
6696 		if (ret < 0)
6697 			return ret;
6698 		return cp->len;
6699 	}
6700 	ret = security_sid_to_context(secid, NULL, &seclen);
6701 	if (ret < 0)
6702 		return ret;
6703 	return seclen;
6704 }
6705 
selinux_lsmprop_to_secctx(struct lsm_prop * prop,struct lsm_context * cp)6706 static int selinux_lsmprop_to_secctx(struct lsm_prop *prop,
6707 				     struct lsm_context *cp)
6708 {
6709 	return selinux_secid_to_secctx(prop->selinux.secid, cp);
6710 }
6711 
selinux_secctx_to_secid(const char * secdata,u32 seclen,u32 * secid)6712 static int selinux_secctx_to_secid(const char *secdata, u32 seclen, u32 *secid)
6713 {
6714 	return security_context_to_sid(secdata, seclen,
6715 				       secid, GFP_KERNEL);
6716 }
6717 
selinux_release_secctx(struct lsm_context * cp)6718 static void selinux_release_secctx(struct lsm_context *cp)
6719 {
6720 	if (cp->id == LSM_ID_SELINUX) {
6721 		kfree(cp->context);
6722 		cp->context = NULL;
6723 		cp->id = LSM_ID_UNDEF;
6724 	}
6725 }
6726 
selinux_inode_invalidate_secctx(struct inode * inode)6727 static void selinux_inode_invalidate_secctx(struct inode *inode)
6728 {
6729 	struct inode_security_struct *isec = selinux_inode(inode);
6730 
6731 	spin_lock(&isec->lock);
6732 	isec->initialized = LABEL_INVALID;
6733 	spin_unlock(&isec->lock);
6734 }
6735 
6736 /*
6737  *	called with inode->i_mutex locked
6738  */
selinux_inode_notifysecctx(struct inode * inode,void * ctx,u32 ctxlen)6739 static int selinux_inode_notifysecctx(struct inode *inode, void *ctx, u32 ctxlen)
6740 {
6741 	int rc = selinux_inode_setsecurity(inode, XATTR_SELINUX_SUFFIX,
6742 					   ctx, ctxlen, 0);
6743 	/* Do not return error when suppressing label (SBLABEL_MNT not set). */
6744 	return rc == -EOPNOTSUPP ? 0 : rc;
6745 }
6746 
6747 /*
6748  *	called with inode->i_mutex locked
6749  */
selinux_inode_setsecctx(struct dentry * dentry,void * ctx,u32 ctxlen)6750 static int selinux_inode_setsecctx(struct dentry *dentry, void *ctx, u32 ctxlen)
6751 {
6752 	return __vfs_setxattr_locked(&nop_mnt_idmap, dentry, XATTR_NAME_SELINUX,
6753 				     ctx, ctxlen, 0, NULL);
6754 }
6755 
selinux_inode_getsecctx(struct inode * inode,struct lsm_context * cp)6756 static int selinux_inode_getsecctx(struct inode *inode, struct lsm_context *cp)
6757 {
6758 	int len;
6759 	len = selinux_inode_getsecurity(&nop_mnt_idmap, inode,
6760 					XATTR_SELINUX_SUFFIX,
6761 					(void **)&cp->context, true);
6762 	if (len < 0)
6763 		return len;
6764 	cp->len = len;
6765 	cp->id = LSM_ID_SELINUX;
6766 	return 0;
6767 }
6768 #ifdef CONFIG_KEYS
6769 
selinux_key_alloc(struct key * k,const struct cred * cred,unsigned long flags)6770 static int selinux_key_alloc(struct key *k, const struct cred *cred,
6771 			     unsigned long flags)
6772 {
6773 	const struct task_security_struct *tsec;
6774 	struct key_security_struct *ksec = selinux_key(k);
6775 
6776 	tsec = selinux_cred(cred);
6777 	if (tsec->keycreate_sid)
6778 		ksec->sid = tsec->keycreate_sid;
6779 	else
6780 		ksec->sid = tsec->sid;
6781 
6782 	return 0;
6783 }
6784 
selinux_key_permission(key_ref_t key_ref,const struct cred * cred,enum key_need_perm need_perm)6785 static int selinux_key_permission(key_ref_t key_ref,
6786 				  const struct cred *cred,
6787 				  enum key_need_perm need_perm)
6788 {
6789 	struct key *key;
6790 	struct key_security_struct *ksec;
6791 	u32 perm, sid;
6792 
6793 	switch (need_perm) {
6794 	case KEY_NEED_VIEW:
6795 		perm = KEY__VIEW;
6796 		break;
6797 	case KEY_NEED_READ:
6798 		perm = KEY__READ;
6799 		break;
6800 	case KEY_NEED_WRITE:
6801 		perm = KEY__WRITE;
6802 		break;
6803 	case KEY_NEED_SEARCH:
6804 		perm = KEY__SEARCH;
6805 		break;
6806 	case KEY_NEED_LINK:
6807 		perm = KEY__LINK;
6808 		break;
6809 	case KEY_NEED_SETATTR:
6810 		perm = KEY__SETATTR;
6811 		break;
6812 	case KEY_NEED_UNLINK:
6813 	case KEY_SYSADMIN_OVERRIDE:
6814 	case KEY_AUTHTOKEN_OVERRIDE:
6815 	case KEY_DEFER_PERM_CHECK:
6816 		return 0;
6817 	default:
6818 		WARN_ON(1);
6819 		return -EPERM;
6820 
6821 	}
6822 
6823 	sid = cred_sid(cred);
6824 	key = key_ref_to_ptr(key_ref);
6825 	ksec = selinux_key(key);
6826 
6827 	return avc_has_perm(sid, ksec->sid, SECCLASS_KEY, perm, NULL);
6828 }
6829 
selinux_key_getsecurity(struct key * key,char ** _buffer)6830 static int selinux_key_getsecurity(struct key *key, char **_buffer)
6831 {
6832 	struct key_security_struct *ksec = selinux_key(key);
6833 	char *context = NULL;
6834 	unsigned len;
6835 	int rc;
6836 
6837 	rc = security_sid_to_context(ksec->sid,
6838 				     &context, &len);
6839 	if (!rc)
6840 		rc = len;
6841 	*_buffer = context;
6842 	return rc;
6843 }
6844 
6845 #ifdef CONFIG_KEY_NOTIFICATIONS
selinux_watch_key(struct key * key)6846 static int selinux_watch_key(struct key *key)
6847 {
6848 	struct key_security_struct *ksec = selinux_key(key);
6849 	u32 sid = current_sid();
6850 
6851 	return avc_has_perm(sid, ksec->sid, SECCLASS_KEY, KEY__VIEW, NULL);
6852 }
6853 #endif
6854 #endif
6855 
6856 #ifdef CONFIG_SECURITY_INFINIBAND
selinux_ib_pkey_access(void * ib_sec,u64 subnet_prefix,u16 pkey_val)6857 static int selinux_ib_pkey_access(void *ib_sec, u64 subnet_prefix, u16 pkey_val)
6858 {
6859 	struct common_audit_data ad;
6860 	int err;
6861 	u32 sid = 0;
6862 	struct ib_security_struct *sec = ib_sec;
6863 	struct lsm_ibpkey_audit ibpkey;
6864 
6865 	err = sel_ib_pkey_sid(subnet_prefix, pkey_val, &sid);
6866 	if (err)
6867 		return err;
6868 
6869 	ad.type = LSM_AUDIT_DATA_IBPKEY;
6870 	ibpkey.subnet_prefix = subnet_prefix;
6871 	ibpkey.pkey = pkey_val;
6872 	ad.u.ibpkey = &ibpkey;
6873 	return avc_has_perm(sec->sid, sid,
6874 			    SECCLASS_INFINIBAND_PKEY,
6875 			    INFINIBAND_PKEY__ACCESS, &ad);
6876 }
6877 
selinux_ib_endport_manage_subnet(void * ib_sec,const char * dev_name,u8 port_num)6878 static int selinux_ib_endport_manage_subnet(void *ib_sec, const char *dev_name,
6879 					    u8 port_num)
6880 {
6881 	struct common_audit_data ad;
6882 	int err;
6883 	u32 sid = 0;
6884 	struct ib_security_struct *sec = ib_sec;
6885 	struct lsm_ibendport_audit ibendport;
6886 
6887 	err = security_ib_endport_sid(dev_name, port_num,
6888 				      &sid);
6889 
6890 	if (err)
6891 		return err;
6892 
6893 	ad.type = LSM_AUDIT_DATA_IBENDPORT;
6894 	ibendport.dev_name = dev_name;
6895 	ibendport.port = port_num;
6896 	ad.u.ibendport = &ibendport;
6897 	return avc_has_perm(sec->sid, sid,
6898 			    SECCLASS_INFINIBAND_ENDPORT,
6899 			    INFINIBAND_ENDPORT__MANAGE_SUBNET, &ad);
6900 }
6901 
selinux_ib_alloc_security(void * ib_sec)6902 static int selinux_ib_alloc_security(void *ib_sec)
6903 {
6904 	struct ib_security_struct *sec = selinux_ib(ib_sec);
6905 
6906 	sec->sid = current_sid();
6907 	return 0;
6908 }
6909 #endif
6910 
6911 #ifdef CONFIG_BPF_SYSCALL
selinux_bpf(int cmd,union bpf_attr * attr,unsigned int size,bool kernel)6912 static int selinux_bpf(int cmd, union bpf_attr *attr,
6913 		       unsigned int size, bool kernel)
6914 {
6915 	u32 sid = current_sid();
6916 	int ret;
6917 
6918 	switch (cmd) {
6919 	case BPF_MAP_CREATE:
6920 		ret = avc_has_perm(sid, sid, SECCLASS_BPF, BPF__MAP_CREATE,
6921 				   NULL);
6922 		break;
6923 	case BPF_PROG_LOAD:
6924 		ret = avc_has_perm(sid, sid, SECCLASS_BPF, BPF__PROG_LOAD,
6925 				   NULL);
6926 		break;
6927 	default:
6928 		ret = 0;
6929 		break;
6930 	}
6931 
6932 	return ret;
6933 }
6934 
bpf_map_fmode_to_av(fmode_t fmode)6935 static u32 bpf_map_fmode_to_av(fmode_t fmode)
6936 {
6937 	u32 av = 0;
6938 
6939 	if (fmode & FMODE_READ)
6940 		av |= BPF__MAP_READ;
6941 	if (fmode & FMODE_WRITE)
6942 		av |= BPF__MAP_WRITE;
6943 	return av;
6944 }
6945 
6946 /* This function will check the file pass through unix socket or binder to see
6947  * if it is a bpf related object. And apply corresponding checks on the bpf
6948  * object based on the type. The bpf maps and programs, not like other files and
6949  * socket, are using a shared anonymous inode inside the kernel as their inode.
6950  * So checking that inode cannot identify if the process have privilege to
6951  * access the bpf object and that's why we have to add this additional check in
6952  * selinux_file_receive and selinux_binder_transfer_files.
6953  */
bpf_fd_pass(const struct file * file,u32 sid)6954 static int bpf_fd_pass(const struct file *file, u32 sid)
6955 {
6956 	struct bpf_security_struct *bpfsec;
6957 	struct bpf_prog *prog;
6958 	struct bpf_map *map;
6959 	int ret;
6960 
6961 	if (file->f_op == &bpf_map_fops) {
6962 		map = file->private_data;
6963 		bpfsec = map->security;
6964 		ret = avc_has_perm(sid, bpfsec->sid, SECCLASS_BPF,
6965 				   bpf_map_fmode_to_av(file->f_mode), NULL);
6966 		if (ret)
6967 			return ret;
6968 	} else if (file->f_op == &bpf_prog_fops) {
6969 		prog = file->private_data;
6970 		bpfsec = prog->aux->security;
6971 		ret = avc_has_perm(sid, bpfsec->sid, SECCLASS_BPF,
6972 				   BPF__PROG_RUN, NULL);
6973 		if (ret)
6974 			return ret;
6975 	}
6976 	return 0;
6977 }
6978 
selinux_bpf_map(struct bpf_map * map,fmode_t fmode)6979 static int selinux_bpf_map(struct bpf_map *map, fmode_t fmode)
6980 {
6981 	u32 sid = current_sid();
6982 	struct bpf_security_struct *bpfsec;
6983 
6984 	bpfsec = map->security;
6985 	return avc_has_perm(sid, bpfsec->sid, SECCLASS_BPF,
6986 			    bpf_map_fmode_to_av(fmode), NULL);
6987 }
6988 
selinux_bpf_prog(struct bpf_prog * prog)6989 static int selinux_bpf_prog(struct bpf_prog *prog)
6990 {
6991 	u32 sid = current_sid();
6992 	struct bpf_security_struct *bpfsec;
6993 
6994 	bpfsec = prog->aux->security;
6995 	return avc_has_perm(sid, bpfsec->sid, SECCLASS_BPF,
6996 			    BPF__PROG_RUN, NULL);
6997 }
6998 
selinux_bpf_map_create(struct bpf_map * map,union bpf_attr * attr,struct bpf_token * token,bool kernel)6999 static int selinux_bpf_map_create(struct bpf_map *map, union bpf_attr *attr,
7000 				  struct bpf_token *token, bool kernel)
7001 {
7002 	struct bpf_security_struct *bpfsec;
7003 
7004 	bpfsec = kzalloc(sizeof(*bpfsec), GFP_KERNEL);
7005 	if (!bpfsec)
7006 		return -ENOMEM;
7007 
7008 	bpfsec->sid = current_sid();
7009 	map->security = bpfsec;
7010 
7011 	return 0;
7012 }
7013 
selinux_bpf_map_free(struct bpf_map * map)7014 static void selinux_bpf_map_free(struct bpf_map *map)
7015 {
7016 	struct bpf_security_struct *bpfsec = map->security;
7017 
7018 	map->security = NULL;
7019 	kfree(bpfsec);
7020 }
7021 
selinux_bpf_prog_load(struct bpf_prog * prog,union bpf_attr * attr,struct bpf_token * token,bool kernel)7022 static int selinux_bpf_prog_load(struct bpf_prog *prog, union bpf_attr *attr,
7023 				 struct bpf_token *token, bool kernel)
7024 {
7025 	struct bpf_security_struct *bpfsec;
7026 
7027 	bpfsec = kzalloc(sizeof(*bpfsec), GFP_KERNEL);
7028 	if (!bpfsec)
7029 		return -ENOMEM;
7030 
7031 	bpfsec->sid = current_sid();
7032 	prog->aux->security = bpfsec;
7033 
7034 	return 0;
7035 }
7036 
selinux_bpf_prog_free(struct bpf_prog * prog)7037 static void selinux_bpf_prog_free(struct bpf_prog *prog)
7038 {
7039 	struct bpf_security_struct *bpfsec = prog->aux->security;
7040 
7041 	prog->aux->security = NULL;
7042 	kfree(bpfsec);
7043 }
7044 
selinux_bpf_token_create(struct bpf_token * token,union bpf_attr * attr,const struct path * path)7045 static int selinux_bpf_token_create(struct bpf_token *token, union bpf_attr *attr,
7046 				    const struct path *path)
7047 {
7048 	struct bpf_security_struct *bpfsec;
7049 
7050 	bpfsec = kzalloc(sizeof(*bpfsec), GFP_KERNEL);
7051 	if (!bpfsec)
7052 		return -ENOMEM;
7053 
7054 	bpfsec->sid = current_sid();
7055 	token->security = bpfsec;
7056 
7057 	return 0;
7058 }
7059 
selinux_bpf_token_free(struct bpf_token * token)7060 static void selinux_bpf_token_free(struct bpf_token *token)
7061 {
7062 	struct bpf_security_struct *bpfsec = token->security;
7063 
7064 	token->security = NULL;
7065 	kfree(bpfsec);
7066 }
7067 #endif
7068 
7069 struct lsm_blob_sizes selinux_blob_sizes __ro_after_init = {
7070 	.lbs_cred = sizeof(struct task_security_struct),
7071 	.lbs_file = sizeof(struct file_security_struct),
7072 	.lbs_inode = sizeof(struct inode_security_struct),
7073 	.lbs_ipc = sizeof(struct ipc_security_struct),
7074 	.lbs_key = sizeof(struct key_security_struct),
7075 	.lbs_msg_msg = sizeof(struct msg_security_struct),
7076 #ifdef CONFIG_PERF_EVENTS
7077 	.lbs_perf_event = sizeof(struct perf_event_security_struct),
7078 #endif
7079 	.lbs_sock = sizeof(struct sk_security_struct),
7080 	.lbs_superblock = sizeof(struct superblock_security_struct),
7081 	.lbs_xattr_count = SELINUX_INODE_INIT_XATTRS,
7082 	.lbs_tun_dev = sizeof(struct tun_security_struct),
7083 	.lbs_ib = sizeof(struct ib_security_struct),
7084 };
7085 
7086 #ifdef CONFIG_PERF_EVENTS
selinux_perf_event_open(int type)7087 static int selinux_perf_event_open(int type)
7088 {
7089 	u32 requested, sid = current_sid();
7090 
7091 	if (type == PERF_SECURITY_OPEN)
7092 		requested = PERF_EVENT__OPEN;
7093 	else if (type == PERF_SECURITY_CPU)
7094 		requested = PERF_EVENT__CPU;
7095 	else if (type == PERF_SECURITY_KERNEL)
7096 		requested = PERF_EVENT__KERNEL;
7097 	else if (type == PERF_SECURITY_TRACEPOINT)
7098 		requested = PERF_EVENT__TRACEPOINT;
7099 	else
7100 		return -EINVAL;
7101 
7102 	return avc_has_perm(sid, sid, SECCLASS_PERF_EVENT,
7103 			    requested, NULL);
7104 }
7105 
selinux_perf_event_alloc(struct perf_event * event)7106 static int selinux_perf_event_alloc(struct perf_event *event)
7107 {
7108 	struct perf_event_security_struct *perfsec;
7109 
7110 	perfsec = selinux_perf_event(event->security);
7111 	perfsec->sid = current_sid();
7112 
7113 	return 0;
7114 }
7115 
selinux_perf_event_read(struct perf_event * event)7116 static int selinux_perf_event_read(struct perf_event *event)
7117 {
7118 	struct perf_event_security_struct *perfsec = event->security;
7119 	u32 sid = current_sid();
7120 
7121 	return avc_has_perm(sid, perfsec->sid,
7122 			    SECCLASS_PERF_EVENT, PERF_EVENT__READ, NULL);
7123 }
7124 
selinux_perf_event_write(struct perf_event * event)7125 static int selinux_perf_event_write(struct perf_event *event)
7126 {
7127 	struct perf_event_security_struct *perfsec = event->security;
7128 	u32 sid = current_sid();
7129 
7130 	return avc_has_perm(sid, perfsec->sid,
7131 			    SECCLASS_PERF_EVENT, PERF_EVENT__WRITE, NULL);
7132 }
7133 #endif
7134 
7135 #ifdef CONFIG_IO_URING
7136 /**
7137  * selinux_uring_override_creds - check the requested cred override
7138  * @new: the target creds
7139  *
7140  * Check to see if the current task is allowed to override it's credentials
7141  * to service an io_uring operation.
7142  */
selinux_uring_override_creds(const struct cred * new)7143 static int selinux_uring_override_creds(const struct cred *new)
7144 {
7145 	return avc_has_perm(current_sid(), cred_sid(new),
7146 			    SECCLASS_IO_URING, IO_URING__OVERRIDE_CREDS, NULL);
7147 }
7148 
7149 /**
7150  * selinux_uring_sqpoll - check if a io_uring polling thread can be created
7151  *
7152  * Check to see if the current task is allowed to create a new io_uring
7153  * kernel polling thread.
7154  */
selinux_uring_sqpoll(void)7155 static int selinux_uring_sqpoll(void)
7156 {
7157 	u32 sid = current_sid();
7158 
7159 	return avc_has_perm(sid, sid,
7160 			    SECCLASS_IO_URING, IO_URING__SQPOLL, NULL);
7161 }
7162 
7163 /**
7164  * selinux_uring_cmd - check if IORING_OP_URING_CMD is allowed
7165  * @ioucmd: the io_uring command structure
7166  *
7167  * Check to see if the current domain is allowed to execute an
7168  * IORING_OP_URING_CMD against the device/file specified in @ioucmd.
7169  *
7170  */
selinux_uring_cmd(struct io_uring_cmd * ioucmd)7171 static int selinux_uring_cmd(struct io_uring_cmd *ioucmd)
7172 {
7173 	struct file *file = ioucmd->file;
7174 	struct inode *inode = file_inode(file);
7175 	struct inode_security_struct *isec = selinux_inode(inode);
7176 	struct common_audit_data ad;
7177 
7178 	ad.type = LSM_AUDIT_DATA_FILE;
7179 	ad.u.file = file;
7180 
7181 	return avc_has_perm(current_sid(), isec->sid,
7182 			    SECCLASS_IO_URING, IO_URING__CMD, &ad);
7183 }
7184 
7185 /**
7186  * selinux_uring_allowed - check if io_uring_setup() can be called
7187  *
7188  * Check to see if the current task is allowed to call io_uring_setup().
7189  */
selinux_uring_allowed(void)7190 static int selinux_uring_allowed(void)
7191 {
7192 	u32 sid = current_sid();
7193 
7194 	return avc_has_perm(sid, sid, SECCLASS_IO_URING, IO_URING__ALLOWED,
7195 			    NULL);
7196 }
7197 #endif /* CONFIG_IO_URING */
7198 
7199 static const struct lsm_id selinux_lsmid = {
7200 	.name = "selinux",
7201 	.id = LSM_ID_SELINUX,
7202 };
7203 
7204 /*
7205  * IMPORTANT NOTE: When adding new hooks, please be careful to keep this order:
7206  * 1. any hooks that don't belong to (2.) or (3.) below,
7207  * 2. hooks that both access structures allocated by other hooks, and allocate
7208  *    structures that can be later accessed by other hooks (mostly "cloning"
7209  *    hooks),
7210  * 3. hooks that only allocate structures that can be later accessed by other
7211  *    hooks ("allocating" hooks).
7212  *
7213  * Please follow block comment delimiters in the list to keep this order.
7214  */
7215 static struct security_hook_list selinux_hooks[] __ro_after_init = {
7216 	LSM_HOOK_INIT(binder_set_context_mgr, selinux_binder_set_context_mgr),
7217 	LSM_HOOK_INIT(binder_transaction, selinux_binder_transaction),
7218 	LSM_HOOK_INIT(binder_transfer_binder, selinux_binder_transfer_binder),
7219 	LSM_HOOK_INIT(binder_transfer_file, selinux_binder_transfer_file),
7220 
7221 	LSM_HOOK_INIT(ptrace_access_check, selinux_ptrace_access_check),
7222 	LSM_HOOK_INIT(ptrace_traceme, selinux_ptrace_traceme),
7223 	LSM_HOOK_INIT(capget, selinux_capget),
7224 	LSM_HOOK_INIT(capset, selinux_capset),
7225 	LSM_HOOK_INIT(capable, selinux_capable),
7226 	LSM_HOOK_INIT(quotactl, selinux_quotactl),
7227 	LSM_HOOK_INIT(quota_on, selinux_quota_on),
7228 	LSM_HOOK_INIT(syslog, selinux_syslog),
7229 	LSM_HOOK_INIT(vm_enough_memory, selinux_vm_enough_memory),
7230 
7231 	LSM_HOOK_INIT(netlink_send, selinux_netlink_send),
7232 
7233 	LSM_HOOK_INIT(bprm_creds_for_exec, selinux_bprm_creds_for_exec),
7234 	LSM_HOOK_INIT(bprm_committing_creds, selinux_bprm_committing_creds),
7235 	LSM_HOOK_INIT(bprm_committed_creds, selinux_bprm_committed_creds),
7236 
7237 	LSM_HOOK_INIT(sb_free_mnt_opts, selinux_free_mnt_opts),
7238 	LSM_HOOK_INIT(sb_mnt_opts_compat, selinux_sb_mnt_opts_compat),
7239 	LSM_HOOK_INIT(sb_remount, selinux_sb_remount),
7240 	LSM_HOOK_INIT(sb_kern_mount, selinux_sb_kern_mount),
7241 	LSM_HOOK_INIT(sb_show_options, selinux_sb_show_options),
7242 	LSM_HOOK_INIT(sb_statfs, selinux_sb_statfs),
7243 	LSM_HOOK_INIT(sb_mount, selinux_mount),
7244 	LSM_HOOK_INIT(sb_umount, selinux_umount),
7245 	LSM_HOOK_INIT(sb_set_mnt_opts, selinux_set_mnt_opts),
7246 	LSM_HOOK_INIT(sb_clone_mnt_opts, selinux_sb_clone_mnt_opts),
7247 
7248 	LSM_HOOK_INIT(move_mount, selinux_move_mount),
7249 
7250 	LSM_HOOK_INIT(dentry_init_security, selinux_dentry_init_security),
7251 	LSM_HOOK_INIT(dentry_create_files_as, selinux_dentry_create_files_as),
7252 
7253 	LSM_HOOK_INIT(inode_free_security, selinux_inode_free_security),
7254 	LSM_HOOK_INIT(inode_init_security, selinux_inode_init_security),
7255 	LSM_HOOK_INIT(inode_init_security_anon, selinux_inode_init_security_anon),
7256 	LSM_HOOK_INIT(inode_create, selinux_inode_create),
7257 	LSM_HOOK_INIT(inode_link, selinux_inode_link),
7258 	LSM_HOOK_INIT(inode_unlink, selinux_inode_unlink),
7259 	LSM_HOOK_INIT(inode_symlink, selinux_inode_symlink),
7260 	LSM_HOOK_INIT(inode_mkdir, selinux_inode_mkdir),
7261 	LSM_HOOK_INIT(inode_rmdir, selinux_inode_rmdir),
7262 	LSM_HOOK_INIT(inode_mknod, selinux_inode_mknod),
7263 	LSM_HOOK_INIT(inode_rename, selinux_inode_rename),
7264 	LSM_HOOK_INIT(inode_readlink, selinux_inode_readlink),
7265 	LSM_HOOK_INIT(inode_follow_link, selinux_inode_follow_link),
7266 	LSM_HOOK_INIT(inode_permission, selinux_inode_permission),
7267 	LSM_HOOK_INIT(inode_setattr, selinux_inode_setattr),
7268 	LSM_HOOK_INIT(inode_getattr, selinux_inode_getattr),
7269 	LSM_HOOK_INIT(inode_xattr_skipcap, selinux_inode_xattr_skipcap),
7270 	LSM_HOOK_INIT(inode_setxattr, selinux_inode_setxattr),
7271 	LSM_HOOK_INIT(inode_post_setxattr, selinux_inode_post_setxattr),
7272 	LSM_HOOK_INIT(inode_getxattr, selinux_inode_getxattr),
7273 	LSM_HOOK_INIT(inode_listxattr, selinux_inode_listxattr),
7274 	LSM_HOOK_INIT(inode_removexattr, selinux_inode_removexattr),
7275 	LSM_HOOK_INIT(inode_set_acl, selinux_inode_set_acl),
7276 	LSM_HOOK_INIT(inode_get_acl, selinux_inode_get_acl),
7277 	LSM_HOOK_INIT(inode_remove_acl, selinux_inode_remove_acl),
7278 	LSM_HOOK_INIT(inode_getsecurity, selinux_inode_getsecurity),
7279 	LSM_HOOK_INIT(inode_setsecurity, selinux_inode_setsecurity),
7280 	LSM_HOOK_INIT(inode_listsecurity, selinux_inode_listsecurity),
7281 	LSM_HOOK_INIT(inode_getlsmprop, selinux_inode_getlsmprop),
7282 	LSM_HOOK_INIT(inode_copy_up, selinux_inode_copy_up),
7283 	LSM_HOOK_INIT(inode_copy_up_xattr, selinux_inode_copy_up_xattr),
7284 	LSM_HOOK_INIT(path_notify, selinux_path_notify),
7285 
7286 	LSM_HOOK_INIT(kernfs_init_security, selinux_kernfs_init_security),
7287 
7288 	LSM_HOOK_INIT(file_permission, selinux_file_permission),
7289 	LSM_HOOK_INIT(file_alloc_security, selinux_file_alloc_security),
7290 	LSM_HOOK_INIT(file_ioctl, selinux_file_ioctl),
7291 	LSM_HOOK_INIT(file_ioctl_compat, selinux_file_ioctl_compat),
7292 	LSM_HOOK_INIT(mmap_file, selinux_mmap_file),
7293 	LSM_HOOK_INIT(mmap_addr, selinux_mmap_addr),
7294 	LSM_HOOK_INIT(file_mprotect, selinux_file_mprotect),
7295 	LSM_HOOK_INIT(file_lock, selinux_file_lock),
7296 	LSM_HOOK_INIT(file_fcntl, selinux_file_fcntl),
7297 	LSM_HOOK_INIT(file_set_fowner, selinux_file_set_fowner),
7298 	LSM_HOOK_INIT(file_send_sigiotask, selinux_file_send_sigiotask),
7299 	LSM_HOOK_INIT(file_receive, selinux_file_receive),
7300 
7301 	LSM_HOOK_INIT(file_open, selinux_file_open),
7302 
7303 	LSM_HOOK_INIT(task_alloc, selinux_task_alloc),
7304 	LSM_HOOK_INIT(cred_prepare, selinux_cred_prepare),
7305 	LSM_HOOK_INIT(cred_transfer, selinux_cred_transfer),
7306 	LSM_HOOK_INIT(cred_getsecid, selinux_cred_getsecid),
7307 	LSM_HOOK_INIT(cred_getlsmprop, selinux_cred_getlsmprop),
7308 	LSM_HOOK_INIT(kernel_act_as, selinux_kernel_act_as),
7309 	LSM_HOOK_INIT(kernel_create_files_as, selinux_kernel_create_files_as),
7310 	LSM_HOOK_INIT(kernel_module_request, selinux_kernel_module_request),
7311 	LSM_HOOK_INIT(kernel_load_data, selinux_kernel_load_data),
7312 	LSM_HOOK_INIT(kernel_read_file, selinux_kernel_read_file),
7313 	LSM_HOOK_INIT(task_setpgid, selinux_task_setpgid),
7314 	LSM_HOOK_INIT(task_getpgid, selinux_task_getpgid),
7315 	LSM_HOOK_INIT(task_getsid, selinux_task_getsid),
7316 	LSM_HOOK_INIT(current_getlsmprop_subj, selinux_current_getlsmprop_subj),
7317 	LSM_HOOK_INIT(task_getlsmprop_obj, selinux_task_getlsmprop_obj),
7318 	LSM_HOOK_INIT(task_setnice, selinux_task_setnice),
7319 	LSM_HOOK_INIT(task_setioprio, selinux_task_setioprio),
7320 	LSM_HOOK_INIT(task_getioprio, selinux_task_getioprio),
7321 	LSM_HOOK_INIT(task_prlimit, selinux_task_prlimit),
7322 	LSM_HOOK_INIT(task_setrlimit, selinux_task_setrlimit),
7323 	LSM_HOOK_INIT(task_setscheduler, selinux_task_setscheduler),
7324 	LSM_HOOK_INIT(task_getscheduler, selinux_task_getscheduler),
7325 	LSM_HOOK_INIT(task_movememory, selinux_task_movememory),
7326 	LSM_HOOK_INIT(task_kill, selinux_task_kill),
7327 	LSM_HOOK_INIT(task_to_inode, selinux_task_to_inode),
7328 	LSM_HOOK_INIT(userns_create, selinux_userns_create),
7329 
7330 	LSM_HOOK_INIT(ipc_permission, selinux_ipc_permission),
7331 	LSM_HOOK_INIT(ipc_getlsmprop, selinux_ipc_getlsmprop),
7332 
7333 	LSM_HOOK_INIT(msg_queue_associate, selinux_msg_queue_associate),
7334 	LSM_HOOK_INIT(msg_queue_msgctl, selinux_msg_queue_msgctl),
7335 	LSM_HOOK_INIT(msg_queue_msgsnd, selinux_msg_queue_msgsnd),
7336 	LSM_HOOK_INIT(msg_queue_msgrcv, selinux_msg_queue_msgrcv),
7337 
7338 	LSM_HOOK_INIT(shm_associate, selinux_shm_associate),
7339 	LSM_HOOK_INIT(shm_shmctl, selinux_shm_shmctl),
7340 	LSM_HOOK_INIT(shm_shmat, selinux_shm_shmat),
7341 
7342 	LSM_HOOK_INIT(sem_associate, selinux_sem_associate),
7343 	LSM_HOOK_INIT(sem_semctl, selinux_sem_semctl),
7344 	LSM_HOOK_INIT(sem_semop, selinux_sem_semop),
7345 
7346 	LSM_HOOK_INIT(d_instantiate, selinux_d_instantiate),
7347 
7348 	LSM_HOOK_INIT(getselfattr, selinux_getselfattr),
7349 	LSM_HOOK_INIT(setselfattr, selinux_setselfattr),
7350 	LSM_HOOK_INIT(getprocattr, selinux_getprocattr),
7351 	LSM_HOOK_INIT(setprocattr, selinux_setprocattr),
7352 
7353 	LSM_HOOK_INIT(ismaclabel, selinux_ismaclabel),
7354 	LSM_HOOK_INIT(secctx_to_secid, selinux_secctx_to_secid),
7355 	LSM_HOOK_INIT(release_secctx, selinux_release_secctx),
7356 	LSM_HOOK_INIT(inode_invalidate_secctx, selinux_inode_invalidate_secctx),
7357 	LSM_HOOK_INIT(inode_notifysecctx, selinux_inode_notifysecctx),
7358 	LSM_HOOK_INIT(inode_setsecctx, selinux_inode_setsecctx),
7359 
7360 	LSM_HOOK_INIT(unix_stream_connect, selinux_socket_unix_stream_connect),
7361 	LSM_HOOK_INIT(unix_may_send, selinux_socket_unix_may_send),
7362 
7363 	LSM_HOOK_INIT(socket_create, selinux_socket_create),
7364 	LSM_HOOK_INIT(socket_post_create, selinux_socket_post_create),
7365 	LSM_HOOK_INIT(socket_socketpair, selinux_socket_socketpair),
7366 	LSM_HOOK_INIT(socket_bind, selinux_socket_bind),
7367 	LSM_HOOK_INIT(socket_connect, selinux_socket_connect),
7368 	LSM_HOOK_INIT(socket_listen, selinux_socket_listen),
7369 	LSM_HOOK_INIT(socket_accept, selinux_socket_accept),
7370 	LSM_HOOK_INIT(socket_sendmsg, selinux_socket_sendmsg),
7371 	LSM_HOOK_INIT(socket_recvmsg, selinux_socket_recvmsg),
7372 	LSM_HOOK_INIT(socket_getsockname, selinux_socket_getsockname),
7373 	LSM_HOOK_INIT(socket_getpeername, selinux_socket_getpeername),
7374 	LSM_HOOK_INIT(socket_getsockopt, selinux_socket_getsockopt),
7375 	LSM_HOOK_INIT(socket_setsockopt, selinux_socket_setsockopt),
7376 	LSM_HOOK_INIT(socket_shutdown, selinux_socket_shutdown),
7377 	LSM_HOOK_INIT(socket_sock_rcv_skb, selinux_socket_sock_rcv_skb),
7378 	LSM_HOOK_INIT(socket_getpeersec_stream,
7379 			selinux_socket_getpeersec_stream),
7380 	LSM_HOOK_INIT(socket_getpeersec_dgram, selinux_socket_getpeersec_dgram),
7381 	LSM_HOOK_INIT(sk_free_security, selinux_sk_free_security),
7382 	LSM_HOOK_INIT(sk_clone_security, selinux_sk_clone_security),
7383 	LSM_HOOK_INIT(sk_getsecid, selinux_sk_getsecid),
7384 	LSM_HOOK_INIT(sock_graft, selinux_sock_graft),
7385 	LSM_HOOK_INIT(sctp_assoc_request, selinux_sctp_assoc_request),
7386 	LSM_HOOK_INIT(sctp_sk_clone, selinux_sctp_sk_clone),
7387 	LSM_HOOK_INIT(sctp_bind_connect, selinux_sctp_bind_connect),
7388 	LSM_HOOK_INIT(sctp_assoc_established, selinux_sctp_assoc_established),
7389 	LSM_HOOK_INIT(mptcp_add_subflow, selinux_mptcp_add_subflow),
7390 	LSM_HOOK_INIT(inet_conn_request, selinux_inet_conn_request),
7391 	LSM_HOOK_INIT(inet_csk_clone, selinux_inet_csk_clone),
7392 	LSM_HOOK_INIT(inet_conn_established, selinux_inet_conn_established),
7393 	LSM_HOOK_INIT(secmark_relabel_packet, selinux_secmark_relabel_packet),
7394 	LSM_HOOK_INIT(secmark_refcount_inc, selinux_secmark_refcount_inc),
7395 	LSM_HOOK_INIT(secmark_refcount_dec, selinux_secmark_refcount_dec),
7396 	LSM_HOOK_INIT(req_classify_flow, selinux_req_classify_flow),
7397 	LSM_HOOK_INIT(tun_dev_create, selinux_tun_dev_create),
7398 	LSM_HOOK_INIT(tun_dev_attach_queue, selinux_tun_dev_attach_queue),
7399 	LSM_HOOK_INIT(tun_dev_attach, selinux_tun_dev_attach),
7400 	LSM_HOOK_INIT(tun_dev_open, selinux_tun_dev_open),
7401 #ifdef CONFIG_SECURITY_INFINIBAND
7402 	LSM_HOOK_INIT(ib_pkey_access, selinux_ib_pkey_access),
7403 	LSM_HOOK_INIT(ib_endport_manage_subnet,
7404 		      selinux_ib_endport_manage_subnet),
7405 #endif
7406 #ifdef CONFIG_SECURITY_NETWORK_XFRM
7407 	LSM_HOOK_INIT(xfrm_policy_free_security, selinux_xfrm_policy_free),
7408 	LSM_HOOK_INIT(xfrm_policy_delete_security, selinux_xfrm_policy_delete),
7409 	LSM_HOOK_INIT(xfrm_state_free_security, selinux_xfrm_state_free),
7410 	LSM_HOOK_INIT(xfrm_state_delete_security, selinux_xfrm_state_delete),
7411 	LSM_HOOK_INIT(xfrm_policy_lookup, selinux_xfrm_policy_lookup),
7412 	LSM_HOOK_INIT(xfrm_state_pol_flow_match,
7413 			selinux_xfrm_state_pol_flow_match),
7414 	LSM_HOOK_INIT(xfrm_decode_session, selinux_xfrm_decode_session),
7415 #endif
7416 
7417 #ifdef CONFIG_KEYS
7418 	LSM_HOOK_INIT(key_permission, selinux_key_permission),
7419 	LSM_HOOK_INIT(key_getsecurity, selinux_key_getsecurity),
7420 #ifdef CONFIG_KEY_NOTIFICATIONS
7421 	LSM_HOOK_INIT(watch_key, selinux_watch_key),
7422 #endif
7423 #endif
7424 
7425 #ifdef CONFIG_AUDIT
7426 	LSM_HOOK_INIT(audit_rule_known, selinux_audit_rule_known),
7427 	LSM_HOOK_INIT(audit_rule_match, selinux_audit_rule_match),
7428 	LSM_HOOK_INIT(audit_rule_free, selinux_audit_rule_free),
7429 #endif
7430 
7431 #ifdef CONFIG_BPF_SYSCALL
7432 	LSM_HOOK_INIT(bpf, selinux_bpf),
7433 	LSM_HOOK_INIT(bpf_map, selinux_bpf_map),
7434 	LSM_HOOK_INIT(bpf_prog, selinux_bpf_prog),
7435 	LSM_HOOK_INIT(bpf_map_free, selinux_bpf_map_free),
7436 	LSM_HOOK_INIT(bpf_prog_free, selinux_bpf_prog_free),
7437 	LSM_HOOK_INIT(bpf_token_free, selinux_bpf_token_free),
7438 #endif
7439 
7440 #ifdef CONFIG_PERF_EVENTS
7441 	LSM_HOOK_INIT(perf_event_open, selinux_perf_event_open),
7442 	LSM_HOOK_INIT(perf_event_read, selinux_perf_event_read),
7443 	LSM_HOOK_INIT(perf_event_write, selinux_perf_event_write),
7444 #endif
7445 
7446 #ifdef CONFIG_IO_URING
7447 	LSM_HOOK_INIT(uring_override_creds, selinux_uring_override_creds),
7448 	LSM_HOOK_INIT(uring_sqpoll, selinux_uring_sqpoll),
7449 	LSM_HOOK_INIT(uring_cmd, selinux_uring_cmd),
7450 	LSM_HOOK_INIT(uring_allowed, selinux_uring_allowed),
7451 #endif
7452 
7453 	/*
7454 	 * PUT "CLONING" (ACCESSING + ALLOCATING) HOOKS HERE
7455 	 */
7456 	LSM_HOOK_INIT(fs_context_submount, selinux_fs_context_submount),
7457 	LSM_HOOK_INIT(fs_context_dup, selinux_fs_context_dup),
7458 	LSM_HOOK_INIT(fs_context_parse_param, selinux_fs_context_parse_param),
7459 	LSM_HOOK_INIT(sb_eat_lsm_opts, selinux_sb_eat_lsm_opts),
7460 #ifdef CONFIG_SECURITY_NETWORK_XFRM
7461 	LSM_HOOK_INIT(xfrm_policy_clone_security, selinux_xfrm_policy_clone),
7462 #endif
7463 
7464 	/*
7465 	 * PUT "ALLOCATING" HOOKS HERE
7466 	 */
7467 	LSM_HOOK_INIT(msg_msg_alloc_security, selinux_msg_msg_alloc_security),
7468 	LSM_HOOK_INIT(msg_queue_alloc_security,
7469 		      selinux_msg_queue_alloc_security),
7470 	LSM_HOOK_INIT(shm_alloc_security, selinux_shm_alloc_security),
7471 	LSM_HOOK_INIT(sb_alloc_security, selinux_sb_alloc_security),
7472 	LSM_HOOK_INIT(inode_alloc_security, selinux_inode_alloc_security),
7473 	LSM_HOOK_INIT(sem_alloc_security, selinux_sem_alloc_security),
7474 	LSM_HOOK_INIT(secid_to_secctx, selinux_secid_to_secctx),
7475 	LSM_HOOK_INIT(lsmprop_to_secctx, selinux_lsmprop_to_secctx),
7476 	LSM_HOOK_INIT(inode_getsecctx, selinux_inode_getsecctx),
7477 	LSM_HOOK_INIT(sk_alloc_security, selinux_sk_alloc_security),
7478 	LSM_HOOK_INIT(tun_dev_alloc_security, selinux_tun_dev_alloc_security),
7479 #ifdef CONFIG_SECURITY_INFINIBAND
7480 	LSM_HOOK_INIT(ib_alloc_security, selinux_ib_alloc_security),
7481 #endif
7482 #ifdef CONFIG_SECURITY_NETWORK_XFRM
7483 	LSM_HOOK_INIT(xfrm_policy_alloc_security, selinux_xfrm_policy_alloc),
7484 	LSM_HOOK_INIT(xfrm_state_alloc, selinux_xfrm_state_alloc),
7485 	LSM_HOOK_INIT(xfrm_state_alloc_acquire,
7486 		      selinux_xfrm_state_alloc_acquire),
7487 #endif
7488 #ifdef CONFIG_KEYS
7489 	LSM_HOOK_INIT(key_alloc, selinux_key_alloc),
7490 #endif
7491 #ifdef CONFIG_AUDIT
7492 	LSM_HOOK_INIT(audit_rule_init, selinux_audit_rule_init),
7493 #endif
7494 #ifdef CONFIG_BPF_SYSCALL
7495 	LSM_HOOK_INIT(bpf_map_create, selinux_bpf_map_create),
7496 	LSM_HOOK_INIT(bpf_prog_load, selinux_bpf_prog_load),
7497 	LSM_HOOK_INIT(bpf_token_create, selinux_bpf_token_create),
7498 #endif
7499 #ifdef CONFIG_PERF_EVENTS
7500 	LSM_HOOK_INIT(perf_event_alloc, selinux_perf_event_alloc),
7501 #endif
7502 };
7503 
selinux_init(void)7504 static __init int selinux_init(void)
7505 {
7506 	pr_info("SELinux:  Initializing.\n");
7507 
7508 	memset(&selinux_state, 0, sizeof(selinux_state));
7509 	enforcing_set(selinux_enforcing_boot);
7510 	selinux_avc_init();
7511 	mutex_init(&selinux_state.status_lock);
7512 	mutex_init(&selinux_state.policy_mutex);
7513 
7514 	/* Set the security state for the initial task. */
7515 	cred_init_security();
7516 
7517 	default_noexec = !(VM_DATA_DEFAULT_FLAGS & VM_EXEC);
7518 	if (!default_noexec)
7519 		pr_notice("SELinux:  virtual memory is executable by default\n");
7520 
7521 	avc_init();
7522 
7523 	avtab_cache_init();
7524 
7525 	ebitmap_cache_init();
7526 
7527 	hashtab_cache_init();
7528 
7529 	security_add_hooks(selinux_hooks, ARRAY_SIZE(selinux_hooks),
7530 			   &selinux_lsmid);
7531 
7532 	if (avc_add_callback(selinux_netcache_avc_callback, AVC_CALLBACK_RESET))
7533 		panic("SELinux: Unable to register AVC netcache callback\n");
7534 
7535 	if (avc_add_callback(selinux_lsm_notifier_avc_callback, AVC_CALLBACK_RESET))
7536 		panic("SELinux: Unable to register AVC LSM notifier callback\n");
7537 
7538 	if (selinux_enforcing_boot)
7539 		pr_debug("SELinux:  Starting in enforcing mode\n");
7540 	else
7541 		pr_debug("SELinux:  Starting in permissive mode\n");
7542 
7543 	fs_validate_description("selinux", selinux_fs_parameters);
7544 
7545 	return 0;
7546 }
7547 
delayed_superblock_init(struct super_block * sb,void * unused)7548 static void delayed_superblock_init(struct super_block *sb, void *unused)
7549 {
7550 	selinux_set_mnt_opts(sb, NULL, 0, NULL);
7551 }
7552 
selinux_complete_init(void)7553 void selinux_complete_init(void)
7554 {
7555 	pr_debug("SELinux:  Completing initialization.\n");
7556 
7557 	/* Set up any superblocks initialized prior to the policy load. */
7558 	pr_debug("SELinux:  Setting up existing superblocks.\n");
7559 	iterate_supers(delayed_superblock_init, NULL);
7560 }
7561 
7562 /* SELinux requires early initialization in order to label
7563    all processes and objects when they are created. */
7564 DEFINE_LSM(selinux) = {
7565 	.name = "selinux",
7566 	.flags = LSM_FLAG_LEGACY_MAJOR | LSM_FLAG_EXCLUSIVE,
7567 	.enabled = &selinux_enabled_boot,
7568 	.blobs = &selinux_blob_sizes,
7569 	.init = selinux_init,
7570 };
7571 
7572 #if defined(CONFIG_NETFILTER)
7573 static const struct nf_hook_ops selinux_nf_ops[] = {
7574 	{
7575 		.hook =		selinux_ip_postroute,
7576 		.pf =		NFPROTO_IPV4,
7577 		.hooknum =	NF_INET_POST_ROUTING,
7578 		.priority =	NF_IP_PRI_SELINUX_LAST,
7579 	},
7580 	{
7581 		.hook =		selinux_ip_forward,
7582 		.pf =		NFPROTO_IPV4,
7583 		.hooknum =	NF_INET_FORWARD,
7584 		.priority =	NF_IP_PRI_SELINUX_FIRST,
7585 	},
7586 	{
7587 		.hook =		selinux_ip_output,
7588 		.pf =		NFPROTO_IPV4,
7589 		.hooknum =	NF_INET_LOCAL_OUT,
7590 		.priority =	NF_IP_PRI_SELINUX_FIRST,
7591 	},
7592 #if IS_ENABLED(CONFIG_IPV6)
7593 	{
7594 		.hook =		selinux_ip_postroute,
7595 		.pf =		NFPROTO_IPV6,
7596 		.hooknum =	NF_INET_POST_ROUTING,
7597 		.priority =	NF_IP6_PRI_SELINUX_LAST,
7598 	},
7599 	{
7600 		.hook =		selinux_ip_forward,
7601 		.pf =		NFPROTO_IPV6,
7602 		.hooknum =	NF_INET_FORWARD,
7603 		.priority =	NF_IP6_PRI_SELINUX_FIRST,
7604 	},
7605 	{
7606 		.hook =		selinux_ip_output,
7607 		.pf =		NFPROTO_IPV6,
7608 		.hooknum =	NF_INET_LOCAL_OUT,
7609 		.priority =	NF_IP6_PRI_SELINUX_FIRST,
7610 	},
7611 #endif	/* IPV6 */
7612 };
7613 
selinux_nf_register(struct net * net)7614 static int __net_init selinux_nf_register(struct net *net)
7615 {
7616 	return nf_register_net_hooks(net, selinux_nf_ops,
7617 				     ARRAY_SIZE(selinux_nf_ops));
7618 }
7619 
selinux_nf_unregister(struct net * net)7620 static void __net_exit selinux_nf_unregister(struct net *net)
7621 {
7622 	nf_unregister_net_hooks(net, selinux_nf_ops,
7623 				ARRAY_SIZE(selinux_nf_ops));
7624 }
7625 
7626 static struct pernet_operations selinux_net_ops = {
7627 	.init = selinux_nf_register,
7628 	.exit = selinux_nf_unregister,
7629 };
7630 
selinux_nf_ip_init(void)7631 static int __init selinux_nf_ip_init(void)
7632 {
7633 	int err;
7634 
7635 	if (!selinux_enabled_boot)
7636 		return 0;
7637 
7638 	pr_debug("SELinux:  Registering netfilter hooks\n");
7639 
7640 	err = register_pernet_subsys(&selinux_net_ops);
7641 	if (err)
7642 		panic("SELinux: register_pernet_subsys: error %d\n", err);
7643 
7644 	return 0;
7645 }
7646 __initcall(selinux_nf_ip_init);
7647 #endif /* CONFIG_NETFILTER */
7648