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 if (selinux_initialized() &&
286 isec->initialized != LABEL_INITIALIZED) {
287 if (!may_sleep)
288 return -ECHILD;
289
290 /*
291 * Try reloading the inode security label. This will fail if
292 * @opt_dentry is NULL and no dentry for this inode can be
293 * found; in that case, continue using the old label.
294 */
295 inode_doinit_with_dentry(inode, dentry);
296 }
297 return 0;
298 }
299
inode_security_novalidate(struct inode * inode)300 static struct inode_security_struct *inode_security_novalidate(struct inode *inode)
301 {
302 return selinux_inode(inode);
303 }
304
inode_security_rcu(struct inode * inode,bool rcu)305 static struct inode_security_struct *inode_security_rcu(struct inode *inode, bool rcu)
306 {
307 int error;
308
309 error = __inode_security_revalidate(inode, NULL, !rcu);
310 if (error)
311 return ERR_PTR(error);
312 return selinux_inode(inode);
313 }
314
315 /*
316 * Get the security label of an inode.
317 */
inode_security(struct inode * inode)318 static struct inode_security_struct *inode_security(struct inode *inode)
319 {
320 __inode_security_revalidate(inode, NULL, true);
321 return selinux_inode(inode);
322 }
323
backing_inode_security_novalidate(struct dentry * dentry)324 static struct inode_security_struct *backing_inode_security_novalidate(struct dentry *dentry)
325 {
326 struct inode *inode = d_backing_inode(dentry);
327
328 return selinux_inode(inode);
329 }
330
331 /*
332 * Get the security label of a dentry's backing inode.
333 */
backing_inode_security(struct dentry * dentry)334 static struct inode_security_struct *backing_inode_security(struct dentry *dentry)
335 {
336 struct inode *inode = d_backing_inode(dentry);
337
338 __inode_security_revalidate(inode, dentry, true);
339 return selinux_inode(inode);
340 }
341
inode_free_security(struct inode * inode)342 static void inode_free_security(struct inode *inode)
343 {
344 struct inode_security_struct *isec = selinux_inode(inode);
345 struct superblock_security_struct *sbsec;
346
347 if (!isec)
348 return;
349 sbsec = selinux_superblock(inode->i_sb);
350 /*
351 * As not all inode security structures are in a list, we check for
352 * empty list outside of the lock to make sure that we won't waste
353 * time taking a lock doing nothing.
354 *
355 * The list_del_init() function can be safely called more than once.
356 * It should not be possible for this function to be called with
357 * concurrent list_add(), but for better safety against future changes
358 * in the code, we use list_empty_careful() here.
359 */
360 if (!list_empty_careful(&isec->list)) {
361 spin_lock(&sbsec->isec_lock);
362 list_del_init(&isec->list);
363 spin_unlock(&sbsec->isec_lock);
364 }
365 }
366
367 struct selinux_mnt_opts {
368 u32 fscontext_sid;
369 u32 context_sid;
370 u32 rootcontext_sid;
371 u32 defcontext_sid;
372 };
373
selinux_free_mnt_opts(void * mnt_opts)374 static void selinux_free_mnt_opts(void *mnt_opts)
375 {
376 kfree(mnt_opts);
377 }
378
379 enum {
380 Opt_error = -1,
381 Opt_context = 0,
382 Opt_defcontext = 1,
383 Opt_fscontext = 2,
384 Opt_rootcontext = 3,
385 Opt_seclabel = 4,
386 };
387
388 #define A(s, has_arg) {#s, sizeof(#s) - 1, Opt_##s, has_arg}
389 static const struct {
390 const char *name;
391 int len;
392 int opt;
393 bool has_arg;
394 } tokens[] = {
395 A(context, true),
396 A(fscontext, true),
397 A(defcontext, true),
398 A(rootcontext, true),
399 A(seclabel, false),
400 };
401 #undef A
402
match_opt_prefix(char * s,int l,char ** arg)403 static int match_opt_prefix(char *s, int l, char **arg)
404 {
405 int i;
406
407 for (i = 0; i < ARRAY_SIZE(tokens); i++) {
408 size_t len = tokens[i].len;
409 if (len > l || memcmp(s, tokens[i].name, len))
410 continue;
411 if (tokens[i].has_arg) {
412 if (len == l || s[len] != '=')
413 continue;
414 *arg = s + len + 1;
415 } else if (len != l)
416 continue;
417 return tokens[i].opt;
418 }
419 return Opt_error;
420 }
421
422 #define SEL_MOUNT_FAIL_MSG "SELinux: duplicate or incompatible mount options\n"
423
may_context_mount_sb_relabel(u32 sid,struct superblock_security_struct * sbsec,const struct cred * cred)424 static int may_context_mount_sb_relabel(u32 sid,
425 struct superblock_security_struct *sbsec,
426 const struct cred *cred)
427 {
428 const struct task_security_struct *tsec = selinux_cred(cred);
429 int rc;
430
431 rc = avc_has_perm(tsec->sid, sbsec->sid, SECCLASS_FILESYSTEM,
432 FILESYSTEM__RELABELFROM, NULL);
433 if (rc)
434 return rc;
435
436 rc = avc_has_perm(tsec->sid, sid, SECCLASS_FILESYSTEM,
437 FILESYSTEM__RELABELTO, NULL);
438 return rc;
439 }
440
may_context_mount_inode_relabel(u32 sid,struct superblock_security_struct * sbsec,const struct cred * cred)441 static int may_context_mount_inode_relabel(u32 sid,
442 struct superblock_security_struct *sbsec,
443 const struct cred *cred)
444 {
445 const struct task_security_struct *tsec = selinux_cred(cred);
446 int rc;
447 rc = avc_has_perm(tsec->sid, sbsec->sid, SECCLASS_FILESYSTEM,
448 FILESYSTEM__RELABELFROM, NULL);
449 if (rc)
450 return rc;
451
452 rc = avc_has_perm(sid, sbsec->sid, SECCLASS_FILESYSTEM,
453 FILESYSTEM__ASSOCIATE, NULL);
454 return rc;
455 }
456
selinux_is_genfs_special_handling(struct super_block * sb)457 static int selinux_is_genfs_special_handling(struct super_block *sb)
458 {
459 /* Special handling. Genfs but also in-core setxattr handler */
460 return !strcmp(sb->s_type->name, "sysfs") ||
461 !strcmp(sb->s_type->name, "pstore") ||
462 !strcmp(sb->s_type->name, "debugfs") ||
463 !strcmp(sb->s_type->name, "tracefs") ||
464 !strcmp(sb->s_type->name, "rootfs") ||
465 (selinux_policycap_cgroupseclabel() &&
466 (!strcmp(sb->s_type->name, "cgroup") ||
467 !strcmp(sb->s_type->name, "cgroup2")));
468 }
469
selinux_is_sblabel_mnt(struct super_block * sb)470 static int selinux_is_sblabel_mnt(struct super_block *sb)
471 {
472 struct superblock_security_struct *sbsec = selinux_superblock(sb);
473
474 /*
475 * IMPORTANT: Double-check logic in this function when adding a new
476 * SECURITY_FS_USE_* definition!
477 */
478 BUILD_BUG_ON(SECURITY_FS_USE_MAX != 7);
479
480 switch (sbsec->behavior) {
481 case SECURITY_FS_USE_XATTR:
482 case SECURITY_FS_USE_TRANS:
483 case SECURITY_FS_USE_TASK:
484 case SECURITY_FS_USE_NATIVE:
485 return 1;
486
487 case SECURITY_FS_USE_GENFS:
488 return selinux_is_genfs_special_handling(sb);
489
490 /* Never allow relabeling on context mounts */
491 case SECURITY_FS_USE_MNTPOINT:
492 case SECURITY_FS_USE_NONE:
493 default:
494 return 0;
495 }
496 }
497
sb_check_xattr_support(struct super_block * sb)498 static int sb_check_xattr_support(struct super_block *sb)
499 {
500 struct superblock_security_struct *sbsec = selinux_superblock(sb);
501 struct dentry *root = sb->s_root;
502 struct inode *root_inode = d_backing_inode(root);
503 u32 sid;
504 int rc;
505
506 /*
507 * Make sure that the xattr handler exists and that no
508 * error other than -ENODATA is returned by getxattr on
509 * the root directory. -ENODATA is ok, as this may be
510 * the first boot of the SELinux kernel before we have
511 * assigned xattr values to the filesystem.
512 */
513 if (!(root_inode->i_opflags & IOP_XATTR)) {
514 pr_warn("SELinux: (dev %s, type %s) has no xattr support\n",
515 sb->s_id, sb->s_type->name);
516 goto fallback;
517 }
518
519 rc = __vfs_getxattr(root, root_inode, XATTR_NAME_SELINUX, NULL, 0);
520 if (rc < 0 && rc != -ENODATA) {
521 if (rc == -EOPNOTSUPP) {
522 pr_warn("SELinux: (dev %s, type %s) has no security xattr handler\n",
523 sb->s_id, sb->s_type->name);
524 goto fallback;
525 } else {
526 pr_warn("SELinux: (dev %s, type %s) getxattr errno %d\n",
527 sb->s_id, sb->s_type->name, -rc);
528 return rc;
529 }
530 }
531 return 0;
532
533 fallback:
534 /* No xattr support - try to fallback to genfs if possible. */
535 rc = security_genfs_sid(sb->s_type->name, "/",
536 SECCLASS_DIR, &sid);
537 if (rc)
538 return -EOPNOTSUPP;
539
540 pr_warn("SELinux: (dev %s, type %s) falling back to genfs\n",
541 sb->s_id, sb->s_type->name);
542 sbsec->behavior = SECURITY_FS_USE_GENFS;
543 sbsec->sid = sid;
544 return 0;
545 }
546
sb_finish_set_opts(struct super_block * sb)547 static int sb_finish_set_opts(struct super_block *sb)
548 {
549 struct superblock_security_struct *sbsec = selinux_superblock(sb);
550 struct dentry *root = sb->s_root;
551 struct inode *root_inode = d_backing_inode(root);
552 int rc = 0;
553
554 if (sbsec->behavior == SECURITY_FS_USE_XATTR) {
555 rc = sb_check_xattr_support(sb);
556 if (rc)
557 return rc;
558 }
559
560 sbsec->flags |= SE_SBINITIALIZED;
561
562 /*
563 * Explicitly set or clear SBLABEL_MNT. It's not sufficient to simply
564 * leave the flag untouched because sb_clone_mnt_opts might be handing
565 * us a superblock that needs the flag to be cleared.
566 */
567 if (selinux_is_sblabel_mnt(sb))
568 sbsec->flags |= SBLABEL_MNT;
569 else
570 sbsec->flags &= ~SBLABEL_MNT;
571
572 /* Initialize the root inode. */
573 rc = inode_doinit_with_dentry(root_inode, root);
574
575 /* Initialize any other inodes associated with the superblock, e.g.
576 inodes created prior to initial policy load or inodes created
577 during get_sb by a pseudo filesystem that directly
578 populates itself. */
579 spin_lock(&sbsec->isec_lock);
580 while (!list_empty(&sbsec->isec_head)) {
581 struct inode_security_struct *isec =
582 list_first_entry(&sbsec->isec_head,
583 struct inode_security_struct, list);
584 struct inode *inode = isec->inode;
585 list_del_init(&isec->list);
586 spin_unlock(&sbsec->isec_lock);
587 inode = igrab(inode);
588 if (inode) {
589 if (!IS_PRIVATE(inode))
590 inode_doinit_with_dentry(inode, NULL);
591 iput(inode);
592 }
593 spin_lock(&sbsec->isec_lock);
594 }
595 spin_unlock(&sbsec->isec_lock);
596 return rc;
597 }
598
bad_option(struct superblock_security_struct * sbsec,char flag,u32 old_sid,u32 new_sid)599 static int bad_option(struct superblock_security_struct *sbsec, char flag,
600 u32 old_sid, u32 new_sid)
601 {
602 char mnt_flags = sbsec->flags & SE_MNTMASK;
603
604 /* check if the old mount command had the same options */
605 if (sbsec->flags & SE_SBINITIALIZED)
606 if (!(sbsec->flags & flag) ||
607 (old_sid != new_sid))
608 return 1;
609
610 /* check if we were passed the same options twice,
611 * aka someone passed context=a,context=b
612 */
613 if (!(sbsec->flags & SE_SBINITIALIZED))
614 if (mnt_flags & flag)
615 return 1;
616 return 0;
617 }
618
619 /*
620 * Allow filesystems with binary mount data to explicitly set mount point
621 * labeling information.
622 */
selinux_set_mnt_opts(struct super_block * sb,void * mnt_opts,unsigned long kern_flags,unsigned long * set_kern_flags)623 static int selinux_set_mnt_opts(struct super_block *sb,
624 void *mnt_opts,
625 unsigned long kern_flags,
626 unsigned long *set_kern_flags)
627 {
628 const struct cred *cred = current_cred();
629 struct superblock_security_struct *sbsec = selinux_superblock(sb);
630 struct dentry *root = sb->s_root;
631 struct selinux_mnt_opts *opts = mnt_opts;
632 struct inode_security_struct *root_isec;
633 u32 fscontext_sid = 0, context_sid = 0, rootcontext_sid = 0;
634 u32 defcontext_sid = 0;
635 int rc = 0;
636
637 /*
638 * Specifying internal flags without providing a place to
639 * place the results is not allowed
640 */
641 if (kern_flags && !set_kern_flags)
642 return -EINVAL;
643
644 mutex_lock(&sbsec->lock);
645
646 if (!selinux_initialized()) {
647 if (!opts) {
648 /* Defer initialization until selinux_complete_init,
649 after the initial policy is loaded and the security
650 server is ready to handle calls. */
651 if (kern_flags & SECURITY_LSM_NATIVE_LABELS) {
652 sbsec->flags |= SE_SBNATIVE;
653 *set_kern_flags |= SECURITY_LSM_NATIVE_LABELS;
654 }
655 goto out;
656 }
657 rc = -EINVAL;
658 pr_warn("SELinux: Unable to set superblock options "
659 "before the security server is initialized\n");
660 goto out;
661 }
662
663 /*
664 * Binary mount data FS will come through this function twice. Once
665 * from an explicit call and once from the generic calls from the vfs.
666 * Since the generic VFS calls will not contain any security mount data
667 * we need to skip the double mount verification.
668 *
669 * This does open a hole in which we will not notice if the first
670 * mount using this sb set explicit options and a second mount using
671 * this sb does not set any security options. (The first options
672 * will be used for both mounts)
673 */
674 if ((sbsec->flags & SE_SBINITIALIZED) && (sb->s_type->fs_flags & FS_BINARY_MOUNTDATA)
675 && !opts)
676 goto out;
677
678 root_isec = backing_inode_security_novalidate(root);
679
680 /*
681 * parse the mount options, check if they are valid sids.
682 * also check if someone is trying to mount the same sb more
683 * than once with different security options.
684 */
685 if (opts) {
686 if (opts->fscontext_sid) {
687 fscontext_sid = opts->fscontext_sid;
688 if (bad_option(sbsec, FSCONTEXT_MNT, sbsec->sid,
689 fscontext_sid))
690 goto out_double_mount;
691 sbsec->flags |= FSCONTEXT_MNT;
692 }
693 if (opts->context_sid) {
694 context_sid = opts->context_sid;
695 if (bad_option(sbsec, CONTEXT_MNT, sbsec->mntpoint_sid,
696 context_sid))
697 goto out_double_mount;
698 sbsec->flags |= CONTEXT_MNT;
699 }
700 if (opts->rootcontext_sid) {
701 rootcontext_sid = opts->rootcontext_sid;
702 if (bad_option(sbsec, ROOTCONTEXT_MNT, root_isec->sid,
703 rootcontext_sid))
704 goto out_double_mount;
705 sbsec->flags |= ROOTCONTEXT_MNT;
706 }
707 if (opts->defcontext_sid) {
708 defcontext_sid = opts->defcontext_sid;
709 if (bad_option(sbsec, DEFCONTEXT_MNT, sbsec->def_sid,
710 defcontext_sid))
711 goto out_double_mount;
712 sbsec->flags |= DEFCONTEXT_MNT;
713 }
714 }
715
716 if (sbsec->flags & SE_SBINITIALIZED) {
717 /* previously mounted with options, but not on this attempt? */
718 if ((sbsec->flags & SE_MNTMASK) && !opts)
719 goto out_double_mount;
720 rc = 0;
721 goto out;
722 }
723
724 if (strcmp(sb->s_type->name, "proc") == 0)
725 sbsec->flags |= SE_SBPROC | SE_SBGENFS;
726
727 if (!strcmp(sb->s_type->name, "debugfs") ||
728 !strcmp(sb->s_type->name, "tracefs") ||
729 !strcmp(sb->s_type->name, "binder") ||
730 !strcmp(sb->s_type->name, "bpf") ||
731 !strcmp(sb->s_type->name, "pstore") ||
732 !strcmp(sb->s_type->name, "securityfs"))
733 sbsec->flags |= SE_SBGENFS;
734
735 if (!strcmp(sb->s_type->name, "sysfs") ||
736 !strcmp(sb->s_type->name, "cgroup") ||
737 !strcmp(sb->s_type->name, "cgroup2"))
738 sbsec->flags |= SE_SBGENFS | SE_SBGENFS_XATTR;
739
740 if (!sbsec->behavior) {
741 /*
742 * Determine the labeling behavior to use for this
743 * filesystem type.
744 */
745 rc = security_fs_use(sb);
746 if (rc) {
747 pr_warn("%s: security_fs_use(%s) returned %d\n",
748 __func__, sb->s_type->name, rc);
749 goto out;
750 }
751 }
752
753 /*
754 * If this is a user namespace mount and the filesystem type is not
755 * explicitly whitelisted, then no contexts are allowed on the command
756 * line and security labels must be ignored.
757 */
758 if (sb->s_user_ns != &init_user_ns &&
759 strcmp(sb->s_type->name, "tmpfs") &&
760 strcmp(sb->s_type->name, "ramfs") &&
761 strcmp(sb->s_type->name, "devpts") &&
762 strcmp(sb->s_type->name, "overlay")) {
763 if (context_sid || fscontext_sid || rootcontext_sid ||
764 defcontext_sid) {
765 rc = -EACCES;
766 goto out;
767 }
768 if (sbsec->behavior == SECURITY_FS_USE_XATTR) {
769 sbsec->behavior = SECURITY_FS_USE_MNTPOINT;
770 rc = security_transition_sid(current_sid(),
771 current_sid(),
772 SECCLASS_FILE, NULL,
773 &sbsec->mntpoint_sid);
774 if (rc)
775 goto out;
776 }
777 goto out_set_opts;
778 }
779
780 /* sets the context of the superblock for the fs being mounted. */
781 if (fscontext_sid) {
782 rc = may_context_mount_sb_relabel(fscontext_sid, sbsec, cred);
783 if (rc)
784 goto out;
785
786 sbsec->sid = fscontext_sid;
787 }
788
789 /*
790 * Switch to using mount point labeling behavior.
791 * sets the label used on all file below the mountpoint, and will set
792 * the superblock context if not already set.
793 */
794 if (sbsec->flags & SE_SBNATIVE) {
795 /*
796 * This means we are initializing a superblock that has been
797 * mounted before the SELinux was initialized and the
798 * filesystem requested native labeling. We had already
799 * returned SECURITY_LSM_NATIVE_LABELS in *set_kern_flags
800 * in the original mount attempt, so now we just need to set
801 * the SECURITY_FS_USE_NATIVE behavior.
802 */
803 sbsec->behavior = SECURITY_FS_USE_NATIVE;
804 } else if (kern_flags & SECURITY_LSM_NATIVE_LABELS && !context_sid) {
805 sbsec->behavior = SECURITY_FS_USE_NATIVE;
806 *set_kern_flags |= SECURITY_LSM_NATIVE_LABELS;
807 }
808
809 if (context_sid) {
810 if (!fscontext_sid) {
811 rc = may_context_mount_sb_relabel(context_sid, sbsec,
812 cred);
813 if (rc)
814 goto out;
815 sbsec->sid = context_sid;
816 } else {
817 rc = may_context_mount_inode_relabel(context_sid, sbsec,
818 cred);
819 if (rc)
820 goto out;
821 }
822 if (!rootcontext_sid)
823 rootcontext_sid = context_sid;
824
825 sbsec->mntpoint_sid = context_sid;
826 sbsec->behavior = SECURITY_FS_USE_MNTPOINT;
827 }
828
829 if (rootcontext_sid) {
830 rc = may_context_mount_inode_relabel(rootcontext_sid, sbsec,
831 cred);
832 if (rc)
833 goto out;
834
835 root_isec->sid = rootcontext_sid;
836 root_isec->initialized = LABEL_INITIALIZED;
837 }
838
839 if (defcontext_sid) {
840 if (sbsec->behavior != SECURITY_FS_USE_XATTR &&
841 sbsec->behavior != SECURITY_FS_USE_NATIVE) {
842 rc = -EINVAL;
843 pr_warn("SELinux: defcontext option is "
844 "invalid for this filesystem type\n");
845 goto out;
846 }
847
848 if (defcontext_sid != sbsec->def_sid) {
849 rc = may_context_mount_inode_relabel(defcontext_sid,
850 sbsec, cred);
851 if (rc)
852 goto out;
853 }
854
855 sbsec->def_sid = defcontext_sid;
856 }
857
858 out_set_opts:
859 rc = sb_finish_set_opts(sb);
860 out:
861 mutex_unlock(&sbsec->lock);
862 return rc;
863 out_double_mount:
864 rc = -EINVAL;
865 pr_warn("SELinux: mount invalid. Same superblock, different "
866 "security settings for (dev %s, type %s)\n", sb->s_id,
867 sb->s_type->name);
868 goto out;
869 }
870
selinux_cmp_sb_context(const struct super_block * oldsb,const struct super_block * newsb)871 static int selinux_cmp_sb_context(const struct super_block *oldsb,
872 const struct super_block *newsb)
873 {
874 struct superblock_security_struct *old = selinux_superblock(oldsb);
875 struct superblock_security_struct *new = selinux_superblock(newsb);
876 char oldflags = old->flags & SE_MNTMASK;
877 char newflags = new->flags & SE_MNTMASK;
878
879 if (oldflags != newflags)
880 goto mismatch;
881 if ((oldflags & FSCONTEXT_MNT) && old->sid != new->sid)
882 goto mismatch;
883 if ((oldflags & CONTEXT_MNT) && old->mntpoint_sid != new->mntpoint_sid)
884 goto mismatch;
885 if ((oldflags & DEFCONTEXT_MNT) && old->def_sid != new->def_sid)
886 goto mismatch;
887 if (oldflags & ROOTCONTEXT_MNT) {
888 struct inode_security_struct *oldroot = backing_inode_security(oldsb->s_root);
889 struct inode_security_struct *newroot = backing_inode_security(newsb->s_root);
890 if (oldroot->sid != newroot->sid)
891 goto mismatch;
892 }
893 return 0;
894 mismatch:
895 pr_warn("SELinux: mount invalid. Same superblock, "
896 "different security settings for (dev %s, "
897 "type %s)\n", newsb->s_id, newsb->s_type->name);
898 return -EBUSY;
899 }
900
selinux_sb_clone_mnt_opts(const struct super_block * oldsb,struct super_block * newsb,unsigned long kern_flags,unsigned long * set_kern_flags)901 static int selinux_sb_clone_mnt_opts(const struct super_block *oldsb,
902 struct super_block *newsb,
903 unsigned long kern_flags,
904 unsigned long *set_kern_flags)
905 {
906 int rc = 0;
907 const struct superblock_security_struct *oldsbsec =
908 selinux_superblock(oldsb);
909 struct superblock_security_struct *newsbsec = selinux_superblock(newsb);
910
911 int set_fscontext = (oldsbsec->flags & FSCONTEXT_MNT);
912 int set_context = (oldsbsec->flags & CONTEXT_MNT);
913 int set_rootcontext = (oldsbsec->flags & ROOTCONTEXT_MNT);
914
915 /*
916 * Specifying internal flags without providing a place to
917 * place the results is not allowed.
918 */
919 if (kern_flags && !set_kern_flags)
920 return -EINVAL;
921
922 mutex_lock(&newsbsec->lock);
923
924 /*
925 * if the parent was able to be mounted it clearly had no special lsm
926 * mount options. thus we can safely deal with this superblock later
927 */
928 if (!selinux_initialized()) {
929 if (kern_flags & SECURITY_LSM_NATIVE_LABELS) {
930 newsbsec->flags |= SE_SBNATIVE;
931 *set_kern_flags |= SECURITY_LSM_NATIVE_LABELS;
932 }
933 goto out;
934 }
935
936 /* how can we clone if the old one wasn't set up?? */
937 BUG_ON(!(oldsbsec->flags & SE_SBINITIALIZED));
938
939 /* if fs is reusing a sb, make sure that the contexts match */
940 if (newsbsec->flags & SE_SBINITIALIZED) {
941 mutex_unlock(&newsbsec->lock);
942 if ((kern_flags & SECURITY_LSM_NATIVE_LABELS) && !set_context)
943 *set_kern_flags |= SECURITY_LSM_NATIVE_LABELS;
944 return selinux_cmp_sb_context(oldsb, newsb);
945 }
946
947 newsbsec->flags = oldsbsec->flags;
948
949 newsbsec->sid = oldsbsec->sid;
950 newsbsec->def_sid = oldsbsec->def_sid;
951 newsbsec->behavior = oldsbsec->behavior;
952
953 if (newsbsec->behavior == SECURITY_FS_USE_NATIVE &&
954 !(kern_flags & SECURITY_LSM_NATIVE_LABELS) && !set_context) {
955 rc = security_fs_use(newsb);
956 if (rc)
957 goto out;
958 }
959
960 if (kern_flags & SECURITY_LSM_NATIVE_LABELS && !set_context) {
961 newsbsec->behavior = SECURITY_FS_USE_NATIVE;
962 *set_kern_flags |= SECURITY_LSM_NATIVE_LABELS;
963 }
964
965 if (set_context) {
966 u32 sid = oldsbsec->mntpoint_sid;
967
968 if (!set_fscontext)
969 newsbsec->sid = sid;
970 if (!set_rootcontext) {
971 struct inode_security_struct *newisec = backing_inode_security(newsb->s_root);
972 newisec->sid = sid;
973 }
974 newsbsec->mntpoint_sid = sid;
975 }
976 if (set_rootcontext) {
977 const struct inode_security_struct *oldisec = backing_inode_security(oldsb->s_root);
978 struct inode_security_struct *newisec = backing_inode_security(newsb->s_root);
979
980 newisec->sid = oldisec->sid;
981 }
982
983 sb_finish_set_opts(newsb);
984 out:
985 mutex_unlock(&newsbsec->lock);
986 return rc;
987 }
988
989 /*
990 * NOTE: the caller is responsible for freeing the memory even if on error.
991 */
selinux_add_opt(int token,const char * s,void ** mnt_opts)992 static int selinux_add_opt(int token, const char *s, void **mnt_opts)
993 {
994 struct selinux_mnt_opts *opts = *mnt_opts;
995 u32 *dst_sid;
996 int rc;
997
998 if (token == Opt_seclabel)
999 /* eaten and completely ignored */
1000 return 0;
1001 if (!s)
1002 return -EINVAL;
1003
1004 if (!selinux_initialized()) {
1005 pr_warn("SELinux: Unable to set superblock options before the security server is initialized\n");
1006 return -EINVAL;
1007 }
1008
1009 if (!opts) {
1010 opts = kzalloc(sizeof(*opts), GFP_KERNEL);
1011 if (!opts)
1012 return -ENOMEM;
1013 *mnt_opts = opts;
1014 }
1015
1016 switch (token) {
1017 case Opt_context:
1018 if (opts->context_sid || opts->defcontext_sid)
1019 goto err;
1020 dst_sid = &opts->context_sid;
1021 break;
1022 case Opt_fscontext:
1023 if (opts->fscontext_sid)
1024 goto err;
1025 dst_sid = &opts->fscontext_sid;
1026 break;
1027 case Opt_rootcontext:
1028 if (opts->rootcontext_sid)
1029 goto err;
1030 dst_sid = &opts->rootcontext_sid;
1031 break;
1032 case Opt_defcontext:
1033 if (opts->context_sid || opts->defcontext_sid)
1034 goto err;
1035 dst_sid = &opts->defcontext_sid;
1036 break;
1037 default:
1038 WARN_ON(1);
1039 return -EINVAL;
1040 }
1041 rc = security_context_str_to_sid(s, dst_sid, GFP_KERNEL);
1042 if (rc)
1043 pr_warn("SELinux: security_context_str_to_sid (%s) failed with errno=%d\n",
1044 s, rc);
1045 return rc;
1046
1047 err:
1048 pr_warn(SEL_MOUNT_FAIL_MSG);
1049 return -EINVAL;
1050 }
1051
show_sid(struct seq_file * m,u32 sid)1052 static int show_sid(struct seq_file *m, u32 sid)
1053 {
1054 char *context = NULL;
1055 u32 len;
1056 int rc;
1057
1058 rc = security_sid_to_context(sid, &context, &len);
1059 if (!rc) {
1060 bool has_comma = strchr(context, ',');
1061
1062 seq_putc(m, '=');
1063 if (has_comma)
1064 seq_putc(m, '\"');
1065 seq_escape(m, context, "\"\n\\");
1066 if (has_comma)
1067 seq_putc(m, '\"');
1068 }
1069 kfree(context);
1070 return rc;
1071 }
1072
selinux_sb_show_options(struct seq_file * m,struct super_block * sb)1073 static int selinux_sb_show_options(struct seq_file *m, struct super_block *sb)
1074 {
1075 struct superblock_security_struct *sbsec = selinux_superblock(sb);
1076 int rc;
1077
1078 if (!(sbsec->flags & SE_SBINITIALIZED))
1079 return 0;
1080
1081 if (!selinux_initialized())
1082 return 0;
1083
1084 if (sbsec->flags & FSCONTEXT_MNT) {
1085 seq_putc(m, ',');
1086 seq_puts(m, FSCONTEXT_STR);
1087 rc = show_sid(m, sbsec->sid);
1088 if (rc)
1089 return rc;
1090 }
1091 if (sbsec->flags & CONTEXT_MNT) {
1092 seq_putc(m, ',');
1093 seq_puts(m, CONTEXT_STR);
1094 rc = show_sid(m, sbsec->mntpoint_sid);
1095 if (rc)
1096 return rc;
1097 }
1098 if (sbsec->flags & DEFCONTEXT_MNT) {
1099 seq_putc(m, ',');
1100 seq_puts(m, DEFCONTEXT_STR);
1101 rc = show_sid(m, sbsec->def_sid);
1102 if (rc)
1103 return rc;
1104 }
1105 if (sbsec->flags & ROOTCONTEXT_MNT) {
1106 struct dentry *root = sb->s_root;
1107 struct inode_security_struct *isec = backing_inode_security(root);
1108 seq_putc(m, ',');
1109 seq_puts(m, ROOTCONTEXT_STR);
1110 rc = show_sid(m, isec->sid);
1111 if (rc)
1112 return rc;
1113 }
1114 if (sbsec->flags & SBLABEL_MNT) {
1115 seq_putc(m, ',');
1116 seq_puts(m, SECLABEL_STR);
1117 }
1118 return 0;
1119 }
1120
inode_mode_to_security_class(umode_t mode)1121 static inline u16 inode_mode_to_security_class(umode_t mode)
1122 {
1123 switch (mode & S_IFMT) {
1124 case S_IFSOCK:
1125 return SECCLASS_SOCK_FILE;
1126 case S_IFLNK:
1127 return SECCLASS_LNK_FILE;
1128 case S_IFREG:
1129 return SECCLASS_FILE;
1130 case S_IFBLK:
1131 return SECCLASS_BLK_FILE;
1132 case S_IFDIR:
1133 return SECCLASS_DIR;
1134 case S_IFCHR:
1135 return SECCLASS_CHR_FILE;
1136 case S_IFIFO:
1137 return SECCLASS_FIFO_FILE;
1138
1139 }
1140
1141 return SECCLASS_FILE;
1142 }
1143
default_protocol_stream(int protocol)1144 static inline int default_protocol_stream(int protocol)
1145 {
1146 return (protocol == IPPROTO_IP || protocol == IPPROTO_TCP ||
1147 protocol == IPPROTO_MPTCP);
1148 }
1149
default_protocol_dgram(int protocol)1150 static inline int default_protocol_dgram(int protocol)
1151 {
1152 return (protocol == IPPROTO_IP || protocol == IPPROTO_UDP);
1153 }
1154
socket_type_to_security_class(int family,int type,int protocol)1155 static inline u16 socket_type_to_security_class(int family, int type, int protocol)
1156 {
1157 bool extsockclass = selinux_policycap_extsockclass();
1158
1159 switch (family) {
1160 case PF_UNIX:
1161 switch (type) {
1162 case SOCK_STREAM:
1163 case SOCK_SEQPACKET:
1164 return SECCLASS_UNIX_STREAM_SOCKET;
1165 case SOCK_DGRAM:
1166 case SOCK_RAW:
1167 return SECCLASS_UNIX_DGRAM_SOCKET;
1168 }
1169 break;
1170 case PF_INET:
1171 case PF_INET6:
1172 switch (type) {
1173 case SOCK_STREAM:
1174 case SOCK_SEQPACKET:
1175 if (default_protocol_stream(protocol))
1176 return SECCLASS_TCP_SOCKET;
1177 else if (extsockclass && protocol == IPPROTO_SCTP)
1178 return SECCLASS_SCTP_SOCKET;
1179 else
1180 return SECCLASS_RAWIP_SOCKET;
1181 case SOCK_DGRAM:
1182 if (default_protocol_dgram(protocol))
1183 return SECCLASS_UDP_SOCKET;
1184 else if (extsockclass && (protocol == IPPROTO_ICMP ||
1185 protocol == IPPROTO_ICMPV6))
1186 return SECCLASS_ICMP_SOCKET;
1187 else
1188 return SECCLASS_RAWIP_SOCKET;
1189 case SOCK_DCCP:
1190 return SECCLASS_DCCP_SOCKET;
1191 default:
1192 return SECCLASS_RAWIP_SOCKET;
1193 }
1194 break;
1195 case PF_NETLINK:
1196 switch (protocol) {
1197 case NETLINK_ROUTE:
1198 return SECCLASS_NETLINK_ROUTE_SOCKET;
1199 case NETLINK_SOCK_DIAG:
1200 return SECCLASS_NETLINK_TCPDIAG_SOCKET;
1201 case NETLINK_NFLOG:
1202 return SECCLASS_NETLINK_NFLOG_SOCKET;
1203 case NETLINK_XFRM:
1204 return SECCLASS_NETLINK_XFRM_SOCKET;
1205 case NETLINK_SELINUX:
1206 return SECCLASS_NETLINK_SELINUX_SOCKET;
1207 case NETLINK_ISCSI:
1208 return SECCLASS_NETLINK_ISCSI_SOCKET;
1209 case NETLINK_AUDIT:
1210 return SECCLASS_NETLINK_AUDIT_SOCKET;
1211 case NETLINK_FIB_LOOKUP:
1212 return SECCLASS_NETLINK_FIB_LOOKUP_SOCKET;
1213 case NETLINK_CONNECTOR:
1214 return SECCLASS_NETLINK_CONNECTOR_SOCKET;
1215 case NETLINK_NETFILTER:
1216 return SECCLASS_NETLINK_NETFILTER_SOCKET;
1217 case NETLINK_DNRTMSG:
1218 return SECCLASS_NETLINK_DNRT_SOCKET;
1219 case NETLINK_KOBJECT_UEVENT:
1220 return SECCLASS_NETLINK_KOBJECT_UEVENT_SOCKET;
1221 case NETLINK_GENERIC:
1222 return SECCLASS_NETLINK_GENERIC_SOCKET;
1223 case NETLINK_SCSITRANSPORT:
1224 return SECCLASS_NETLINK_SCSITRANSPORT_SOCKET;
1225 case NETLINK_RDMA:
1226 return SECCLASS_NETLINK_RDMA_SOCKET;
1227 case NETLINK_CRYPTO:
1228 return SECCLASS_NETLINK_CRYPTO_SOCKET;
1229 default:
1230 return SECCLASS_NETLINK_SOCKET;
1231 }
1232 case PF_PACKET:
1233 return SECCLASS_PACKET_SOCKET;
1234 case PF_KEY:
1235 return SECCLASS_KEY_SOCKET;
1236 case PF_APPLETALK:
1237 return SECCLASS_APPLETALK_SOCKET;
1238 }
1239
1240 if (extsockclass) {
1241 switch (family) {
1242 case PF_AX25:
1243 return SECCLASS_AX25_SOCKET;
1244 case PF_IPX:
1245 return SECCLASS_IPX_SOCKET;
1246 case PF_NETROM:
1247 return SECCLASS_NETROM_SOCKET;
1248 case PF_ATMPVC:
1249 return SECCLASS_ATMPVC_SOCKET;
1250 case PF_X25:
1251 return SECCLASS_X25_SOCKET;
1252 case PF_ROSE:
1253 return SECCLASS_ROSE_SOCKET;
1254 case PF_DECnet:
1255 return SECCLASS_DECNET_SOCKET;
1256 case PF_ATMSVC:
1257 return SECCLASS_ATMSVC_SOCKET;
1258 case PF_RDS:
1259 return SECCLASS_RDS_SOCKET;
1260 case PF_IRDA:
1261 return SECCLASS_IRDA_SOCKET;
1262 case PF_PPPOX:
1263 return SECCLASS_PPPOX_SOCKET;
1264 case PF_LLC:
1265 return SECCLASS_LLC_SOCKET;
1266 case PF_CAN:
1267 return SECCLASS_CAN_SOCKET;
1268 case PF_TIPC:
1269 return SECCLASS_TIPC_SOCKET;
1270 case PF_BLUETOOTH:
1271 return SECCLASS_BLUETOOTH_SOCKET;
1272 case PF_IUCV:
1273 return SECCLASS_IUCV_SOCKET;
1274 case PF_RXRPC:
1275 return SECCLASS_RXRPC_SOCKET;
1276 case PF_ISDN:
1277 return SECCLASS_ISDN_SOCKET;
1278 case PF_PHONET:
1279 return SECCLASS_PHONET_SOCKET;
1280 case PF_IEEE802154:
1281 return SECCLASS_IEEE802154_SOCKET;
1282 case PF_CAIF:
1283 return SECCLASS_CAIF_SOCKET;
1284 case PF_ALG:
1285 return SECCLASS_ALG_SOCKET;
1286 case PF_NFC:
1287 return SECCLASS_NFC_SOCKET;
1288 case PF_VSOCK:
1289 return SECCLASS_VSOCK_SOCKET;
1290 case PF_KCM:
1291 return SECCLASS_KCM_SOCKET;
1292 case PF_QIPCRTR:
1293 return SECCLASS_QIPCRTR_SOCKET;
1294 case PF_SMC:
1295 return SECCLASS_SMC_SOCKET;
1296 case PF_XDP:
1297 return SECCLASS_XDP_SOCKET;
1298 case PF_MCTP:
1299 return SECCLASS_MCTP_SOCKET;
1300 #if PF_MAX > 46
1301 #error New address family defined, please update this function.
1302 #endif
1303 }
1304 }
1305
1306 return SECCLASS_SOCKET;
1307 }
1308
selinux_genfs_get_sid(struct dentry * dentry,u16 tclass,u16 flags,u32 * sid)1309 static int selinux_genfs_get_sid(struct dentry *dentry,
1310 u16 tclass,
1311 u16 flags,
1312 u32 *sid)
1313 {
1314 int rc;
1315 struct super_block *sb = dentry->d_sb;
1316 char *buffer, *path;
1317
1318 buffer = (char *)__get_free_page(GFP_KERNEL);
1319 if (!buffer)
1320 return -ENOMEM;
1321
1322 path = dentry_path_raw(dentry, buffer, PAGE_SIZE);
1323 if (IS_ERR(path))
1324 rc = PTR_ERR(path);
1325 else {
1326 if (flags & SE_SBPROC) {
1327 /* each process gets a /proc/PID/ entry. Strip off the
1328 * PID part to get a valid selinux labeling.
1329 * e.g. /proc/1/net/rpc/nfs -> /net/rpc/nfs */
1330 while (path[1] >= '0' && path[1] <= '9') {
1331 path[1] = '/';
1332 path++;
1333 }
1334 }
1335 rc = security_genfs_sid(sb->s_type->name,
1336 path, tclass, sid);
1337 if (rc == -ENOENT) {
1338 /* No match in policy, mark as unlabeled. */
1339 *sid = SECINITSID_UNLABELED;
1340 rc = 0;
1341 }
1342 }
1343 free_page((unsigned long)buffer);
1344 return rc;
1345 }
1346
inode_doinit_use_xattr(struct inode * inode,struct dentry * dentry,u32 def_sid,u32 * sid)1347 static int inode_doinit_use_xattr(struct inode *inode, struct dentry *dentry,
1348 u32 def_sid, u32 *sid)
1349 {
1350 #define INITCONTEXTLEN 255
1351 char *context;
1352 unsigned int len;
1353 int rc;
1354
1355 len = INITCONTEXTLEN;
1356 context = kmalloc(len + 1, GFP_NOFS);
1357 if (!context)
1358 return -ENOMEM;
1359
1360 context[len] = '\0';
1361 rc = __vfs_getxattr(dentry, inode, XATTR_NAME_SELINUX, context, len);
1362 if (rc == -ERANGE) {
1363 kfree(context);
1364
1365 /* Need a larger buffer. Query for the right size. */
1366 rc = __vfs_getxattr(dentry, inode, XATTR_NAME_SELINUX, NULL, 0);
1367 if (rc < 0)
1368 return rc;
1369
1370 len = rc;
1371 context = kmalloc(len + 1, GFP_NOFS);
1372 if (!context)
1373 return -ENOMEM;
1374
1375 context[len] = '\0';
1376 rc = __vfs_getxattr(dentry, inode, XATTR_NAME_SELINUX,
1377 context, len);
1378 }
1379 if (rc < 0) {
1380 kfree(context);
1381 if (rc != -ENODATA) {
1382 pr_warn("SELinux: %s: getxattr returned %d for dev=%s ino=%ld\n",
1383 __func__, -rc, inode->i_sb->s_id, inode->i_ino);
1384 return rc;
1385 }
1386 *sid = def_sid;
1387 return 0;
1388 }
1389
1390 rc = security_context_to_sid_default(context, rc, sid,
1391 def_sid, GFP_NOFS);
1392 if (rc) {
1393 char *dev = inode->i_sb->s_id;
1394 unsigned long ino = inode->i_ino;
1395
1396 if (rc == -EINVAL) {
1397 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",
1398 ino, dev, context);
1399 } else {
1400 pr_warn("SELinux: %s: context_to_sid(%s) returned %d for dev=%s ino=%ld\n",
1401 __func__, context, -rc, dev, ino);
1402 }
1403 }
1404 kfree(context);
1405 return 0;
1406 }
1407
1408 /* The inode's security attributes must be initialized before first use. */
inode_doinit_with_dentry(struct inode * inode,struct dentry * opt_dentry)1409 static int inode_doinit_with_dentry(struct inode *inode, struct dentry *opt_dentry)
1410 {
1411 struct superblock_security_struct *sbsec = NULL;
1412 struct inode_security_struct *isec = selinux_inode(inode);
1413 u32 task_sid, sid = 0;
1414 u16 sclass;
1415 struct dentry *dentry;
1416 int rc = 0;
1417
1418 if (isec->initialized == LABEL_INITIALIZED)
1419 return 0;
1420
1421 spin_lock(&isec->lock);
1422 if (isec->initialized == LABEL_INITIALIZED)
1423 goto out_unlock;
1424
1425 if (isec->sclass == SECCLASS_FILE)
1426 isec->sclass = inode_mode_to_security_class(inode->i_mode);
1427
1428 sbsec = selinux_superblock(inode->i_sb);
1429 if (!(sbsec->flags & SE_SBINITIALIZED)) {
1430 /* Defer initialization until selinux_complete_init,
1431 after the initial policy is loaded and the security
1432 server is ready to handle calls. */
1433 spin_lock(&sbsec->isec_lock);
1434 if (list_empty(&isec->list))
1435 list_add(&isec->list, &sbsec->isec_head);
1436 spin_unlock(&sbsec->isec_lock);
1437 goto out_unlock;
1438 }
1439
1440 sclass = isec->sclass;
1441 task_sid = isec->task_sid;
1442 sid = isec->sid;
1443 isec->initialized = LABEL_PENDING;
1444 spin_unlock(&isec->lock);
1445
1446 switch (sbsec->behavior) {
1447 /*
1448 * In case of SECURITY_FS_USE_NATIVE we need to re-fetch the labels
1449 * via xattr when called from delayed_superblock_init().
1450 */
1451 case SECURITY_FS_USE_NATIVE:
1452 case SECURITY_FS_USE_XATTR:
1453 if (!(inode->i_opflags & IOP_XATTR)) {
1454 sid = sbsec->def_sid;
1455 break;
1456 }
1457 /* Need a dentry, since the xattr API requires one.
1458 Life would be simpler if we could just pass the inode. */
1459 if (opt_dentry) {
1460 /* Called from d_instantiate or d_splice_alias. */
1461 dentry = dget(opt_dentry);
1462 } else {
1463 /*
1464 * Called from selinux_complete_init, try to find a dentry.
1465 * Some filesystems really want a connected one, so try
1466 * that first. We could split SECURITY_FS_USE_XATTR in
1467 * two, depending upon that...
1468 */
1469 dentry = d_find_alias(inode);
1470 if (!dentry)
1471 dentry = d_find_any_alias(inode);
1472 }
1473 if (!dentry) {
1474 /*
1475 * this is can be hit on boot when a file is accessed
1476 * before the policy is loaded. When we load policy we
1477 * may find inodes that have no dentry on the
1478 * sbsec->isec_head list. No reason to complain as these
1479 * will get fixed up the next time we go through
1480 * inode_doinit with a dentry, before these inodes could
1481 * be used again by userspace.
1482 */
1483 goto out_invalid;
1484 }
1485
1486 rc = inode_doinit_use_xattr(inode, dentry, sbsec->def_sid,
1487 &sid);
1488 dput(dentry);
1489 if (rc)
1490 goto out;
1491 break;
1492 case SECURITY_FS_USE_TASK:
1493 sid = task_sid;
1494 break;
1495 case SECURITY_FS_USE_TRANS:
1496 /* Default to the fs SID. */
1497 sid = sbsec->sid;
1498
1499 /* Try to obtain a transition SID. */
1500 rc = security_transition_sid(task_sid, sid,
1501 sclass, NULL, &sid);
1502 if (rc)
1503 goto out;
1504 break;
1505 case SECURITY_FS_USE_MNTPOINT:
1506 sid = sbsec->mntpoint_sid;
1507 break;
1508 default:
1509 /* Default to the fs superblock SID. */
1510 sid = sbsec->sid;
1511
1512 if ((sbsec->flags & SE_SBGENFS) &&
1513 (!S_ISLNK(inode->i_mode) ||
1514 selinux_policycap_genfs_seclabel_symlinks())) {
1515 /* We must have a dentry to determine the label on
1516 * procfs inodes */
1517 if (opt_dentry) {
1518 /* Called from d_instantiate or
1519 * d_splice_alias. */
1520 dentry = dget(opt_dentry);
1521 } else {
1522 /* Called from selinux_complete_init, try to
1523 * find a dentry. Some filesystems really want
1524 * a connected one, so try that first.
1525 */
1526 dentry = d_find_alias(inode);
1527 if (!dentry)
1528 dentry = d_find_any_alias(inode);
1529 }
1530 /*
1531 * This can be hit on boot when a file is accessed
1532 * before the policy is loaded. When we load policy we
1533 * may find inodes that have no dentry on the
1534 * sbsec->isec_head list. No reason to complain as
1535 * these will get fixed up the next time we go through
1536 * inode_doinit() with a dentry, before these inodes
1537 * could be used again by userspace.
1538 */
1539 if (!dentry)
1540 goto out_invalid;
1541 rc = selinux_genfs_get_sid(dentry, sclass,
1542 sbsec->flags, &sid);
1543 if (rc) {
1544 dput(dentry);
1545 goto out;
1546 }
1547
1548 if ((sbsec->flags & SE_SBGENFS_XATTR) &&
1549 (inode->i_opflags & IOP_XATTR)) {
1550 rc = inode_doinit_use_xattr(inode, dentry,
1551 sid, &sid);
1552 if (rc) {
1553 dput(dentry);
1554 goto out;
1555 }
1556 }
1557 dput(dentry);
1558 }
1559 break;
1560 }
1561
1562 out:
1563 spin_lock(&isec->lock);
1564 if (isec->initialized == LABEL_PENDING) {
1565 if (rc) {
1566 isec->initialized = LABEL_INVALID;
1567 goto out_unlock;
1568 }
1569 isec->initialized = LABEL_INITIALIZED;
1570 isec->sid = sid;
1571 }
1572
1573 out_unlock:
1574 spin_unlock(&isec->lock);
1575 return rc;
1576
1577 out_invalid:
1578 spin_lock(&isec->lock);
1579 if (isec->initialized == LABEL_PENDING) {
1580 isec->initialized = LABEL_INVALID;
1581 isec->sid = sid;
1582 }
1583 spin_unlock(&isec->lock);
1584 return 0;
1585 }
1586
1587 /* Convert a Linux signal to an access vector. */
signal_to_av(int sig)1588 static inline u32 signal_to_av(int sig)
1589 {
1590 u32 perm = 0;
1591
1592 switch (sig) {
1593 case SIGCHLD:
1594 /* Commonly granted from child to parent. */
1595 perm = PROCESS__SIGCHLD;
1596 break;
1597 case SIGKILL:
1598 /* Cannot be caught or ignored */
1599 perm = PROCESS__SIGKILL;
1600 break;
1601 case SIGSTOP:
1602 /* Cannot be caught or ignored */
1603 perm = PROCESS__SIGSTOP;
1604 break;
1605 default:
1606 /* All other signals. */
1607 perm = PROCESS__SIGNAL;
1608 break;
1609 }
1610
1611 return perm;
1612 }
1613
1614 #if CAP_LAST_CAP > 63
1615 #error Fix SELinux to handle capabilities > 63.
1616 #endif
1617
1618 /* Check whether a task is allowed to use a capability. */
cred_has_capability(const struct cred * cred,int cap,unsigned int opts,bool initns)1619 static int cred_has_capability(const struct cred *cred,
1620 int cap, unsigned int opts, bool initns)
1621 {
1622 struct common_audit_data ad;
1623 struct av_decision avd;
1624 u16 sclass;
1625 u32 sid = cred_sid(cred);
1626 u32 av = CAP_TO_MASK(cap);
1627 int rc;
1628
1629 ad.type = LSM_AUDIT_DATA_CAP;
1630 ad.u.cap = cap;
1631
1632 switch (CAP_TO_INDEX(cap)) {
1633 case 0:
1634 sclass = initns ? SECCLASS_CAPABILITY : SECCLASS_CAP_USERNS;
1635 break;
1636 case 1:
1637 sclass = initns ? SECCLASS_CAPABILITY2 : SECCLASS_CAP2_USERNS;
1638 break;
1639 default:
1640 pr_err("SELinux: out of range capability %d\n", cap);
1641 BUG();
1642 return -EINVAL;
1643 }
1644
1645 rc = avc_has_perm_noaudit(sid, sid, sclass, av, 0, &avd);
1646 if (!(opts & CAP_OPT_NOAUDIT)) {
1647 int rc2 = avc_audit(sid, sid, sclass, av, &avd, rc, &ad);
1648 if (rc2)
1649 return rc2;
1650 }
1651 return rc;
1652 }
1653
1654 /* Check whether a task has a particular permission to an inode.
1655 The 'adp' parameter is optional and allows other audit
1656 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)1657 static int inode_has_perm(const struct cred *cred,
1658 struct inode *inode,
1659 u32 perms,
1660 struct common_audit_data *adp)
1661 {
1662 struct inode_security_struct *isec;
1663 u32 sid;
1664
1665 if (unlikely(IS_PRIVATE(inode)))
1666 return 0;
1667
1668 sid = cred_sid(cred);
1669 isec = selinux_inode(inode);
1670
1671 return avc_has_perm(sid, isec->sid, isec->sclass, perms, adp);
1672 }
1673
1674 /* Same as inode_has_perm, but pass explicit audit data containing
1675 the dentry to help the auditing code to more easily generate the
1676 pathname if needed. */
dentry_has_perm(const struct cred * cred,struct dentry * dentry,u32 av)1677 static inline int dentry_has_perm(const struct cred *cred,
1678 struct dentry *dentry,
1679 u32 av)
1680 {
1681 struct inode *inode = d_backing_inode(dentry);
1682 struct common_audit_data ad;
1683
1684 ad.type = LSM_AUDIT_DATA_DENTRY;
1685 ad.u.dentry = dentry;
1686 __inode_security_revalidate(inode, dentry, true);
1687 return inode_has_perm(cred, inode, av, &ad);
1688 }
1689
1690 /* Same as inode_has_perm, but pass explicit audit data containing
1691 the path to help the auditing code to more easily generate the
1692 pathname if needed. */
path_has_perm(const struct cred * cred,const struct path * path,u32 av)1693 static inline int path_has_perm(const struct cred *cred,
1694 const struct path *path,
1695 u32 av)
1696 {
1697 struct inode *inode = d_backing_inode(path->dentry);
1698 struct common_audit_data ad;
1699
1700 ad.type = LSM_AUDIT_DATA_PATH;
1701 ad.u.path = *path;
1702 __inode_security_revalidate(inode, path->dentry, true);
1703 return inode_has_perm(cred, inode, av, &ad);
1704 }
1705
1706 /* 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)1707 static inline int file_path_has_perm(const struct cred *cred,
1708 struct file *file,
1709 u32 av)
1710 {
1711 struct common_audit_data ad;
1712
1713 ad.type = LSM_AUDIT_DATA_FILE;
1714 ad.u.file = file;
1715 return inode_has_perm(cred, file_inode(file), av, &ad);
1716 }
1717
1718 #ifdef CONFIG_BPF_SYSCALL
1719 static int bpf_fd_pass(const struct file *file, u32 sid);
1720 #endif
1721
1722 /* Check whether a task can use an open file descriptor to
1723 access an inode in a given way. Check access to the
1724 descriptor itself, and then use dentry_has_perm to
1725 check a particular permission to the file.
1726 Access to the descriptor is implicitly granted if it
1727 has the same SID as the process. If av is zero, then
1728 access to the file is not checked, e.g. for cases
1729 where only the descriptor is affected like seek. */
file_has_perm(const struct cred * cred,struct file * file,u32 av)1730 static int file_has_perm(const struct cred *cred,
1731 struct file *file,
1732 u32 av)
1733 {
1734 struct file_security_struct *fsec = selinux_file(file);
1735 struct inode *inode = file_inode(file);
1736 struct common_audit_data ad;
1737 u32 sid = cred_sid(cred);
1738 int rc;
1739
1740 ad.type = LSM_AUDIT_DATA_FILE;
1741 ad.u.file = file;
1742
1743 if (sid != fsec->sid) {
1744 rc = avc_has_perm(sid, fsec->sid,
1745 SECCLASS_FD,
1746 FD__USE,
1747 &ad);
1748 if (rc)
1749 goto out;
1750 }
1751
1752 #ifdef CONFIG_BPF_SYSCALL
1753 rc = bpf_fd_pass(file, cred_sid(cred));
1754 if (rc)
1755 return rc;
1756 #endif
1757
1758 /* av is zero if only checking access to the descriptor. */
1759 rc = 0;
1760 if (av)
1761 rc = inode_has_perm(cred, inode, av, &ad);
1762
1763 out:
1764 return rc;
1765 }
1766
1767 /*
1768 * Determine the label for an inode that might be unioned.
1769 */
1770 static int
selinux_determine_inode_label(const struct task_security_struct * tsec,struct inode * dir,const struct qstr * name,u16 tclass,u32 * _new_isid)1771 selinux_determine_inode_label(const struct task_security_struct *tsec,
1772 struct inode *dir,
1773 const struct qstr *name, u16 tclass,
1774 u32 *_new_isid)
1775 {
1776 const struct superblock_security_struct *sbsec =
1777 selinux_superblock(dir->i_sb);
1778
1779 if ((sbsec->flags & SE_SBINITIALIZED) &&
1780 (sbsec->behavior == SECURITY_FS_USE_MNTPOINT)) {
1781 *_new_isid = sbsec->mntpoint_sid;
1782 } else if ((sbsec->flags & SBLABEL_MNT) &&
1783 tsec->create_sid) {
1784 *_new_isid = tsec->create_sid;
1785 } else {
1786 const struct inode_security_struct *dsec = inode_security(dir);
1787 return security_transition_sid(tsec->sid,
1788 dsec->sid, tclass,
1789 name, _new_isid);
1790 }
1791
1792 return 0;
1793 }
1794
1795 /* Check whether a task can create a file. */
may_create(struct inode * dir,struct dentry * dentry,u16 tclass)1796 static int may_create(struct inode *dir,
1797 struct dentry *dentry,
1798 u16 tclass)
1799 {
1800 const struct task_security_struct *tsec = selinux_cred(current_cred());
1801 struct inode_security_struct *dsec;
1802 struct superblock_security_struct *sbsec;
1803 u32 sid, newsid;
1804 struct common_audit_data ad;
1805 int rc;
1806
1807 dsec = inode_security(dir);
1808 sbsec = selinux_superblock(dir->i_sb);
1809
1810 sid = tsec->sid;
1811
1812 ad.type = LSM_AUDIT_DATA_DENTRY;
1813 ad.u.dentry = dentry;
1814
1815 rc = avc_has_perm(sid, dsec->sid, SECCLASS_DIR,
1816 DIR__ADD_NAME | DIR__SEARCH,
1817 &ad);
1818 if (rc)
1819 return rc;
1820
1821 rc = selinux_determine_inode_label(tsec, dir, &dentry->d_name, tclass,
1822 &newsid);
1823 if (rc)
1824 return rc;
1825
1826 rc = avc_has_perm(sid, newsid, tclass, FILE__CREATE, &ad);
1827 if (rc)
1828 return rc;
1829
1830 return avc_has_perm(newsid, sbsec->sid,
1831 SECCLASS_FILESYSTEM,
1832 FILESYSTEM__ASSOCIATE, &ad);
1833 }
1834
1835 #define MAY_LINK 0
1836 #define MAY_UNLINK 1
1837 #define MAY_RMDIR 2
1838
1839 /* Check whether a task can link, unlink, or rmdir a file/directory. */
may_link(struct inode * dir,struct dentry * dentry,int kind)1840 static int may_link(struct inode *dir,
1841 struct dentry *dentry,
1842 int kind)
1843
1844 {
1845 struct inode_security_struct *dsec, *isec;
1846 struct common_audit_data ad;
1847 u32 sid = current_sid();
1848 u32 av;
1849 int rc;
1850
1851 dsec = inode_security(dir);
1852 isec = backing_inode_security(dentry);
1853
1854 ad.type = LSM_AUDIT_DATA_DENTRY;
1855 ad.u.dentry = dentry;
1856
1857 av = DIR__SEARCH;
1858 av |= (kind ? DIR__REMOVE_NAME : DIR__ADD_NAME);
1859 rc = avc_has_perm(sid, dsec->sid, SECCLASS_DIR, av, &ad);
1860 if (rc)
1861 return rc;
1862
1863 switch (kind) {
1864 case MAY_LINK:
1865 av = FILE__LINK;
1866 break;
1867 case MAY_UNLINK:
1868 av = FILE__UNLINK;
1869 break;
1870 case MAY_RMDIR:
1871 av = DIR__RMDIR;
1872 break;
1873 default:
1874 pr_warn("SELinux: %s: unrecognized kind %d\n",
1875 __func__, kind);
1876 return 0;
1877 }
1878
1879 rc = avc_has_perm(sid, isec->sid, isec->sclass, av, &ad);
1880 return rc;
1881 }
1882
may_rename(struct inode * old_dir,struct dentry * old_dentry,struct inode * new_dir,struct dentry * new_dentry)1883 static inline int may_rename(struct inode *old_dir,
1884 struct dentry *old_dentry,
1885 struct inode *new_dir,
1886 struct dentry *new_dentry)
1887 {
1888 struct inode_security_struct *old_dsec, *new_dsec, *old_isec, *new_isec;
1889 struct common_audit_data ad;
1890 u32 sid = current_sid();
1891 u32 av;
1892 int old_is_dir, new_is_dir;
1893 int rc;
1894
1895 old_dsec = inode_security(old_dir);
1896 old_isec = backing_inode_security(old_dentry);
1897 old_is_dir = d_is_dir(old_dentry);
1898 new_dsec = inode_security(new_dir);
1899
1900 ad.type = LSM_AUDIT_DATA_DENTRY;
1901
1902 ad.u.dentry = old_dentry;
1903 rc = avc_has_perm(sid, old_dsec->sid, SECCLASS_DIR,
1904 DIR__REMOVE_NAME | DIR__SEARCH, &ad);
1905 if (rc)
1906 return rc;
1907 rc = avc_has_perm(sid, old_isec->sid,
1908 old_isec->sclass, FILE__RENAME, &ad);
1909 if (rc)
1910 return rc;
1911 if (old_is_dir && new_dir != old_dir) {
1912 rc = avc_has_perm(sid, old_isec->sid,
1913 old_isec->sclass, DIR__REPARENT, &ad);
1914 if (rc)
1915 return rc;
1916 }
1917
1918 ad.u.dentry = new_dentry;
1919 av = DIR__ADD_NAME | DIR__SEARCH;
1920 if (d_is_positive(new_dentry))
1921 av |= DIR__REMOVE_NAME;
1922 rc = avc_has_perm(sid, new_dsec->sid, SECCLASS_DIR, av, &ad);
1923 if (rc)
1924 return rc;
1925 if (d_is_positive(new_dentry)) {
1926 new_isec = backing_inode_security(new_dentry);
1927 new_is_dir = d_is_dir(new_dentry);
1928 rc = avc_has_perm(sid, new_isec->sid,
1929 new_isec->sclass,
1930 (new_is_dir ? DIR__RMDIR : FILE__UNLINK), &ad);
1931 if (rc)
1932 return rc;
1933 }
1934
1935 return 0;
1936 }
1937
1938 /* 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)1939 static int superblock_has_perm(const struct cred *cred,
1940 const struct super_block *sb,
1941 u32 perms,
1942 struct common_audit_data *ad)
1943 {
1944 struct superblock_security_struct *sbsec;
1945 u32 sid = cred_sid(cred);
1946
1947 sbsec = selinux_superblock(sb);
1948 return avc_has_perm(sid, sbsec->sid, SECCLASS_FILESYSTEM, perms, ad);
1949 }
1950
1951 /* Convert a Linux mode and permission mask to an access vector. */
file_mask_to_av(int mode,int mask)1952 static inline u32 file_mask_to_av(int mode, int mask)
1953 {
1954 u32 av = 0;
1955
1956 if (!S_ISDIR(mode)) {
1957 if (mask & MAY_EXEC)
1958 av |= FILE__EXECUTE;
1959 if (mask & MAY_READ)
1960 av |= FILE__READ;
1961
1962 if (mask & MAY_APPEND)
1963 av |= FILE__APPEND;
1964 else if (mask & MAY_WRITE)
1965 av |= FILE__WRITE;
1966
1967 } else {
1968 if (mask & MAY_EXEC)
1969 av |= DIR__SEARCH;
1970 if (mask & MAY_WRITE)
1971 av |= DIR__WRITE;
1972 if (mask & MAY_READ)
1973 av |= DIR__READ;
1974 }
1975
1976 return av;
1977 }
1978
1979 /* Convert a Linux file to an access vector. */
file_to_av(const struct file * file)1980 static inline u32 file_to_av(const struct file *file)
1981 {
1982 u32 av = 0;
1983
1984 if (file->f_mode & FMODE_READ)
1985 av |= FILE__READ;
1986 if (file->f_mode & FMODE_WRITE) {
1987 if (file->f_flags & O_APPEND)
1988 av |= FILE__APPEND;
1989 else
1990 av |= FILE__WRITE;
1991 }
1992 if (!av) {
1993 /*
1994 * Special file opened with flags 3 for ioctl-only use.
1995 */
1996 av = FILE__IOCTL;
1997 }
1998
1999 return av;
2000 }
2001
2002 /*
2003 * Convert a file to an access vector and include the correct
2004 * open permission.
2005 */
open_file_to_av(struct file * file)2006 static inline u32 open_file_to_av(struct file *file)
2007 {
2008 u32 av = file_to_av(file);
2009 struct inode *inode = file_inode(file);
2010
2011 if (selinux_policycap_openperm() &&
2012 inode->i_sb->s_magic != SOCKFS_MAGIC)
2013 av |= FILE__OPEN;
2014
2015 return av;
2016 }
2017
2018 /* Hook functions begin here. */
2019
selinux_binder_set_context_mgr(const struct cred * mgr)2020 static int selinux_binder_set_context_mgr(const struct cred *mgr)
2021 {
2022 return avc_has_perm(current_sid(), cred_sid(mgr), SECCLASS_BINDER,
2023 BINDER__SET_CONTEXT_MGR, NULL);
2024 }
2025
selinux_binder_transaction(const struct cred * from,const struct cred * to)2026 static int selinux_binder_transaction(const struct cred *from,
2027 const struct cred *to)
2028 {
2029 u32 mysid = current_sid();
2030 u32 fromsid = cred_sid(from);
2031 u32 tosid = cred_sid(to);
2032 int rc;
2033
2034 if (mysid != fromsid) {
2035 rc = avc_has_perm(mysid, fromsid, SECCLASS_BINDER,
2036 BINDER__IMPERSONATE, NULL);
2037 if (rc)
2038 return rc;
2039 }
2040
2041 return avc_has_perm(fromsid, tosid,
2042 SECCLASS_BINDER, BINDER__CALL, NULL);
2043 }
2044
selinux_binder_transfer_binder(const struct cred * from,const struct cred * to)2045 static int selinux_binder_transfer_binder(const struct cred *from,
2046 const struct cred *to)
2047 {
2048 return avc_has_perm(cred_sid(from), cred_sid(to),
2049 SECCLASS_BINDER, BINDER__TRANSFER,
2050 NULL);
2051 }
2052
selinux_binder_transfer_file(const struct cred * from,const struct cred * to,const struct file * file)2053 static int selinux_binder_transfer_file(const struct cred *from,
2054 const struct cred *to,
2055 const struct file *file)
2056 {
2057 u32 sid = cred_sid(to);
2058 struct file_security_struct *fsec = selinux_file(file);
2059 struct dentry *dentry = file->f_path.dentry;
2060 struct inode_security_struct *isec;
2061 struct common_audit_data ad;
2062 int rc;
2063
2064 ad.type = LSM_AUDIT_DATA_PATH;
2065 ad.u.path = file->f_path;
2066
2067 if (sid != fsec->sid) {
2068 rc = avc_has_perm(sid, fsec->sid,
2069 SECCLASS_FD,
2070 FD__USE,
2071 &ad);
2072 if (rc)
2073 return rc;
2074 }
2075
2076 #ifdef CONFIG_BPF_SYSCALL
2077 rc = bpf_fd_pass(file, sid);
2078 if (rc)
2079 return rc;
2080 #endif
2081
2082 if (unlikely(IS_PRIVATE(d_backing_inode(dentry))))
2083 return 0;
2084
2085 isec = backing_inode_security(dentry);
2086 return avc_has_perm(sid, isec->sid, isec->sclass, file_to_av(file),
2087 &ad);
2088 }
2089
selinux_ptrace_access_check(struct task_struct * child,unsigned int mode)2090 static int selinux_ptrace_access_check(struct task_struct *child,
2091 unsigned int mode)
2092 {
2093 u32 sid = current_sid();
2094 u32 csid = task_sid_obj(child);
2095
2096 if (mode & PTRACE_MODE_READ)
2097 return avc_has_perm(sid, csid, SECCLASS_FILE, FILE__READ,
2098 NULL);
2099
2100 return avc_has_perm(sid, csid, SECCLASS_PROCESS, PROCESS__PTRACE,
2101 NULL);
2102 }
2103
selinux_ptrace_traceme(struct task_struct * parent)2104 static int selinux_ptrace_traceme(struct task_struct *parent)
2105 {
2106 return avc_has_perm(task_sid_obj(parent), task_sid_obj(current),
2107 SECCLASS_PROCESS, PROCESS__PTRACE, NULL);
2108 }
2109
selinux_capget(const struct task_struct * target,kernel_cap_t * effective,kernel_cap_t * inheritable,kernel_cap_t * permitted)2110 static int selinux_capget(const struct task_struct *target, kernel_cap_t *effective,
2111 kernel_cap_t *inheritable, kernel_cap_t *permitted)
2112 {
2113 return avc_has_perm(current_sid(), task_sid_obj(target),
2114 SECCLASS_PROCESS, PROCESS__GETCAP, NULL);
2115 }
2116
selinux_capset(struct cred * new,const struct cred * old,const kernel_cap_t * effective,const kernel_cap_t * inheritable,const kernel_cap_t * permitted)2117 static int selinux_capset(struct cred *new, const struct cred *old,
2118 const kernel_cap_t *effective,
2119 const kernel_cap_t *inheritable,
2120 const kernel_cap_t *permitted)
2121 {
2122 return avc_has_perm(cred_sid(old), cred_sid(new), SECCLASS_PROCESS,
2123 PROCESS__SETCAP, NULL);
2124 }
2125
2126 /*
2127 * (This comment used to live with the selinux_task_setuid hook,
2128 * which was removed).
2129 *
2130 * Since setuid only affects the current process, and since the SELinux
2131 * controls are not based on the Linux identity attributes, SELinux does not
2132 * need to control this operation. However, SELinux does control the use of
2133 * the CAP_SETUID and CAP_SETGID capabilities using the capable hook.
2134 */
2135
selinux_capable(const struct cred * cred,struct user_namespace * ns,int cap,unsigned int opts)2136 static int selinux_capable(const struct cred *cred, struct user_namespace *ns,
2137 int cap, unsigned int opts)
2138 {
2139 return cred_has_capability(cred, cap, opts, ns == &init_user_ns);
2140 }
2141
selinux_quotactl(int cmds,int type,int id,const struct super_block * sb)2142 static int selinux_quotactl(int cmds, int type, int id, const struct super_block *sb)
2143 {
2144 const struct cred *cred = current_cred();
2145 int rc = 0;
2146
2147 if (!sb)
2148 return 0;
2149
2150 switch (cmds) {
2151 case Q_SYNC:
2152 case Q_QUOTAON:
2153 case Q_QUOTAOFF:
2154 case Q_SETINFO:
2155 case Q_SETQUOTA:
2156 case Q_XQUOTAOFF:
2157 case Q_XQUOTAON:
2158 case Q_XSETQLIM:
2159 rc = superblock_has_perm(cred, sb, FILESYSTEM__QUOTAMOD, NULL);
2160 break;
2161 case Q_GETFMT:
2162 case Q_GETINFO:
2163 case Q_GETQUOTA:
2164 case Q_XGETQUOTA:
2165 case Q_XGETQSTAT:
2166 case Q_XGETQSTATV:
2167 case Q_XGETNEXTQUOTA:
2168 rc = superblock_has_perm(cred, sb, FILESYSTEM__QUOTAGET, NULL);
2169 break;
2170 default:
2171 rc = 0; /* let the kernel handle invalid cmds */
2172 break;
2173 }
2174 return rc;
2175 }
2176
selinux_quota_on(struct dentry * dentry)2177 static int selinux_quota_on(struct dentry *dentry)
2178 {
2179 const struct cred *cred = current_cred();
2180
2181 return dentry_has_perm(cred, dentry, FILE__QUOTAON);
2182 }
2183
selinux_syslog(int type)2184 static int selinux_syslog(int type)
2185 {
2186 switch (type) {
2187 case SYSLOG_ACTION_READ_ALL: /* Read last kernel messages */
2188 case SYSLOG_ACTION_SIZE_BUFFER: /* Return size of the log buffer */
2189 return avc_has_perm(current_sid(), SECINITSID_KERNEL,
2190 SECCLASS_SYSTEM, SYSTEM__SYSLOG_READ, NULL);
2191 case SYSLOG_ACTION_CONSOLE_OFF: /* Disable logging to console */
2192 case SYSLOG_ACTION_CONSOLE_ON: /* Enable logging to console */
2193 /* Set level of messages printed to console */
2194 case SYSLOG_ACTION_CONSOLE_LEVEL:
2195 return avc_has_perm(current_sid(), SECINITSID_KERNEL,
2196 SECCLASS_SYSTEM, SYSTEM__SYSLOG_CONSOLE,
2197 NULL);
2198 }
2199 /* All other syslog types */
2200 return avc_has_perm(current_sid(), SECINITSID_KERNEL,
2201 SECCLASS_SYSTEM, SYSTEM__SYSLOG_MOD, NULL);
2202 }
2203
2204 /*
2205 * Check that a process has enough memory to allocate a new virtual
2206 * mapping. 0 means there is enough memory for the allocation to
2207 * succeed and -ENOMEM implies there is not.
2208 *
2209 * Do not audit the selinux permission check, as this is applied to all
2210 * processes that allocate mappings.
2211 */
selinux_vm_enough_memory(struct mm_struct * mm,long pages)2212 static int selinux_vm_enough_memory(struct mm_struct *mm, long pages)
2213 {
2214 int rc, cap_sys_admin = 0;
2215
2216 rc = cred_has_capability(current_cred(), CAP_SYS_ADMIN,
2217 CAP_OPT_NOAUDIT, true);
2218 if (rc == 0)
2219 cap_sys_admin = 1;
2220
2221 return cap_sys_admin;
2222 }
2223
2224 /* binprm security operations */
2225
ptrace_parent_sid(void)2226 static u32 ptrace_parent_sid(void)
2227 {
2228 u32 sid = 0;
2229 struct task_struct *tracer;
2230
2231 rcu_read_lock();
2232 tracer = ptrace_parent(current);
2233 if (tracer)
2234 sid = task_sid_obj(tracer);
2235 rcu_read_unlock();
2236
2237 return sid;
2238 }
2239
check_nnp_nosuid(const struct linux_binprm * bprm,const struct task_security_struct * old_tsec,const struct task_security_struct * new_tsec)2240 static int check_nnp_nosuid(const struct linux_binprm *bprm,
2241 const struct task_security_struct *old_tsec,
2242 const struct task_security_struct *new_tsec)
2243 {
2244 int nnp = (bprm->unsafe & LSM_UNSAFE_NO_NEW_PRIVS);
2245 int nosuid = !mnt_may_suid(bprm->file->f_path.mnt);
2246 int rc;
2247 u32 av;
2248
2249 if (!nnp && !nosuid)
2250 return 0; /* neither NNP nor nosuid */
2251
2252 if (new_tsec->sid == old_tsec->sid)
2253 return 0; /* No change in credentials */
2254
2255 /*
2256 * If the policy enables the nnp_nosuid_transition policy capability,
2257 * then we permit transitions under NNP or nosuid if the
2258 * policy allows the corresponding permission between
2259 * the old and new contexts.
2260 */
2261 if (selinux_policycap_nnp_nosuid_transition()) {
2262 av = 0;
2263 if (nnp)
2264 av |= PROCESS2__NNP_TRANSITION;
2265 if (nosuid)
2266 av |= PROCESS2__NOSUID_TRANSITION;
2267 rc = avc_has_perm(old_tsec->sid, new_tsec->sid,
2268 SECCLASS_PROCESS2, av, NULL);
2269 if (!rc)
2270 return 0;
2271 }
2272
2273 /*
2274 * We also permit NNP or nosuid transitions to bounded SIDs,
2275 * i.e. SIDs that are guaranteed to only be allowed a subset
2276 * of the permissions of the current SID.
2277 */
2278 rc = security_bounded_transition(old_tsec->sid,
2279 new_tsec->sid);
2280 if (!rc)
2281 return 0;
2282
2283 /*
2284 * On failure, preserve the errno values for NNP vs nosuid.
2285 * NNP: Operation not permitted for caller.
2286 * nosuid: Permission denied to file.
2287 */
2288 if (nnp)
2289 return -EPERM;
2290 return -EACCES;
2291 }
2292
selinux_bprm_creds_for_exec(struct linux_binprm * bprm)2293 static int selinux_bprm_creds_for_exec(struct linux_binprm *bprm)
2294 {
2295 const struct task_security_struct *old_tsec;
2296 struct task_security_struct *new_tsec;
2297 struct inode_security_struct *isec;
2298 struct common_audit_data ad;
2299 struct inode *inode = file_inode(bprm->file);
2300 int rc;
2301
2302 /* SELinux context only depends on initial program or script and not
2303 * the script interpreter */
2304
2305 old_tsec = selinux_cred(current_cred());
2306 new_tsec = selinux_cred(bprm->cred);
2307 isec = inode_security(inode);
2308
2309 /* Default to the current task SID. */
2310 new_tsec->sid = old_tsec->sid;
2311 new_tsec->osid = old_tsec->sid;
2312
2313 /* Reset fs, key, and sock SIDs on execve. */
2314 new_tsec->create_sid = 0;
2315 new_tsec->keycreate_sid = 0;
2316 new_tsec->sockcreate_sid = 0;
2317
2318 /*
2319 * Before policy is loaded, label any task outside kernel space
2320 * as SECINITSID_INIT, so that any userspace tasks surviving from
2321 * early boot end up with a label different from SECINITSID_KERNEL
2322 * (if the policy chooses to set SECINITSID_INIT != SECINITSID_KERNEL).
2323 */
2324 if (!selinux_initialized()) {
2325 new_tsec->sid = SECINITSID_INIT;
2326 /* also clear the exec_sid just in case */
2327 new_tsec->exec_sid = 0;
2328 return 0;
2329 }
2330
2331 if (old_tsec->exec_sid) {
2332 new_tsec->sid = old_tsec->exec_sid;
2333 /* Reset exec SID on execve. */
2334 new_tsec->exec_sid = 0;
2335
2336 /* Fail on NNP or nosuid if not an allowed transition. */
2337 rc = check_nnp_nosuid(bprm, old_tsec, new_tsec);
2338 if (rc)
2339 return rc;
2340 } else {
2341 /* Check for a default transition on this program. */
2342 rc = security_transition_sid(old_tsec->sid,
2343 isec->sid, SECCLASS_PROCESS, NULL,
2344 &new_tsec->sid);
2345 if (rc)
2346 return rc;
2347
2348 /*
2349 * Fallback to old SID on NNP or nosuid if not an allowed
2350 * transition.
2351 */
2352 rc = check_nnp_nosuid(bprm, old_tsec, new_tsec);
2353 if (rc)
2354 new_tsec->sid = old_tsec->sid;
2355 }
2356
2357 ad.type = LSM_AUDIT_DATA_FILE;
2358 ad.u.file = bprm->file;
2359
2360 if (new_tsec->sid == old_tsec->sid) {
2361 rc = avc_has_perm(old_tsec->sid, isec->sid,
2362 SECCLASS_FILE, FILE__EXECUTE_NO_TRANS, &ad);
2363 if (rc)
2364 return rc;
2365 } else {
2366 /* Check permissions for the transition. */
2367 rc = avc_has_perm(old_tsec->sid, new_tsec->sid,
2368 SECCLASS_PROCESS, PROCESS__TRANSITION, &ad);
2369 if (rc)
2370 return rc;
2371
2372 rc = avc_has_perm(new_tsec->sid, isec->sid,
2373 SECCLASS_FILE, FILE__ENTRYPOINT, &ad);
2374 if (rc)
2375 return rc;
2376
2377 /* Check for shared state */
2378 if (bprm->unsafe & LSM_UNSAFE_SHARE) {
2379 rc = avc_has_perm(old_tsec->sid, new_tsec->sid,
2380 SECCLASS_PROCESS, PROCESS__SHARE,
2381 NULL);
2382 if (rc)
2383 return -EPERM;
2384 }
2385
2386 /* Make sure that anyone attempting to ptrace over a task that
2387 * changes its SID has the appropriate permit */
2388 if (bprm->unsafe & LSM_UNSAFE_PTRACE) {
2389 u32 ptsid = ptrace_parent_sid();
2390 if (ptsid != 0) {
2391 rc = avc_has_perm(ptsid, new_tsec->sid,
2392 SECCLASS_PROCESS,
2393 PROCESS__PTRACE, NULL);
2394 if (rc)
2395 return -EPERM;
2396 }
2397 }
2398
2399 /* Clear any possibly unsafe personality bits on exec: */
2400 bprm->per_clear |= PER_CLEAR_ON_SETID;
2401
2402 /* Enable secure mode for SIDs transitions unless
2403 the noatsecure permission is granted between
2404 the two SIDs, i.e. ahp returns 0. */
2405 rc = avc_has_perm(old_tsec->sid, new_tsec->sid,
2406 SECCLASS_PROCESS, PROCESS__NOATSECURE,
2407 NULL);
2408 bprm->secureexec |= !!rc;
2409 }
2410
2411 return 0;
2412 }
2413
match_file(const void * p,struct file * file,unsigned fd)2414 static int match_file(const void *p, struct file *file, unsigned fd)
2415 {
2416 return file_has_perm(p, file, file_to_av(file)) ? fd + 1 : 0;
2417 }
2418
2419 /* Derived from fs/exec.c:flush_old_files. */
flush_unauthorized_files(const struct cred * cred,struct files_struct * files)2420 static inline void flush_unauthorized_files(const struct cred *cred,
2421 struct files_struct *files)
2422 {
2423 struct file *file, *devnull = NULL;
2424 struct tty_struct *tty;
2425 int drop_tty = 0;
2426 unsigned n;
2427
2428 tty = get_current_tty();
2429 if (tty) {
2430 spin_lock(&tty->files_lock);
2431 if (!list_empty(&tty->tty_files)) {
2432 struct tty_file_private *file_priv;
2433
2434 /* Revalidate access to controlling tty.
2435 Use file_path_has_perm on the tty path directly
2436 rather than using file_has_perm, as this particular
2437 open file may belong to another process and we are
2438 only interested in the inode-based check here. */
2439 file_priv = list_first_entry(&tty->tty_files,
2440 struct tty_file_private, list);
2441 file = file_priv->file;
2442 if (file_path_has_perm(cred, file, FILE__READ | FILE__WRITE))
2443 drop_tty = 1;
2444 }
2445 spin_unlock(&tty->files_lock);
2446 tty_kref_put(tty);
2447 }
2448 /* Reset controlling tty. */
2449 if (drop_tty)
2450 no_tty();
2451
2452 /* Revalidate access to inherited open files. */
2453 n = iterate_fd(files, 0, match_file, cred);
2454 if (!n) /* none found? */
2455 return;
2456
2457 devnull = dentry_open(&selinux_null, O_RDWR, cred);
2458 if (IS_ERR(devnull))
2459 devnull = NULL;
2460 /* replace all the matching ones with this */
2461 do {
2462 replace_fd(n - 1, devnull, 0);
2463 } while ((n = iterate_fd(files, n, match_file, cred)) != 0);
2464 if (devnull)
2465 fput(devnull);
2466 }
2467
2468 /*
2469 * Prepare a process for imminent new credential changes due to exec
2470 */
selinux_bprm_committing_creds(const struct linux_binprm * bprm)2471 static void selinux_bprm_committing_creds(const struct linux_binprm *bprm)
2472 {
2473 struct task_security_struct *new_tsec;
2474 struct rlimit *rlim, *initrlim;
2475 int rc, i;
2476
2477 new_tsec = selinux_cred(bprm->cred);
2478 if (new_tsec->sid == new_tsec->osid)
2479 return;
2480
2481 /* Close files for which the new task SID is not authorized. */
2482 flush_unauthorized_files(bprm->cred, current->files);
2483
2484 /* Always clear parent death signal on SID transitions. */
2485 current->pdeath_signal = 0;
2486
2487 /* Check whether the new SID can inherit resource limits from the old
2488 * SID. If not, reset all soft limits to the lower of the current
2489 * task's hard limit and the init task's soft limit.
2490 *
2491 * Note that the setting of hard limits (even to lower them) can be
2492 * controlled by the setrlimit check. The inclusion of the init task's
2493 * soft limit into the computation is to avoid resetting soft limits
2494 * higher than the default soft limit for cases where the default is
2495 * lower than the hard limit, e.g. RLIMIT_CORE or RLIMIT_STACK.
2496 */
2497 rc = avc_has_perm(new_tsec->osid, new_tsec->sid, SECCLASS_PROCESS,
2498 PROCESS__RLIMITINH, NULL);
2499 if (rc) {
2500 /* protect against do_prlimit() */
2501 task_lock(current);
2502 for (i = 0; i < RLIM_NLIMITS; i++) {
2503 rlim = current->signal->rlim + i;
2504 initrlim = init_task.signal->rlim + i;
2505 rlim->rlim_cur = min(rlim->rlim_max, initrlim->rlim_cur);
2506 }
2507 task_unlock(current);
2508 if (IS_ENABLED(CONFIG_POSIX_TIMERS))
2509 update_rlimit_cpu(current, rlimit(RLIMIT_CPU));
2510 }
2511 }
2512
2513 /*
2514 * Clean up the process immediately after the installation of new credentials
2515 * due to exec
2516 */
selinux_bprm_committed_creds(const struct linux_binprm * bprm)2517 static void selinux_bprm_committed_creds(const struct linux_binprm *bprm)
2518 {
2519 const struct task_security_struct *tsec = selinux_cred(current_cred());
2520 u32 osid, sid;
2521 int rc;
2522
2523 osid = tsec->osid;
2524 sid = tsec->sid;
2525
2526 if (sid == osid)
2527 return;
2528
2529 /* Check whether the new SID can inherit signal state from the old SID.
2530 * If not, clear itimers to avoid subsequent signal generation and
2531 * flush and unblock signals.
2532 *
2533 * This must occur _after_ the task SID has been updated so that any
2534 * kill done after the flush will be checked against the new SID.
2535 */
2536 rc = avc_has_perm(osid, sid, SECCLASS_PROCESS, PROCESS__SIGINH, NULL);
2537 if (rc) {
2538 clear_itimer();
2539
2540 spin_lock_irq(&unrcu_pointer(current->sighand)->siglock);
2541 if (!fatal_signal_pending(current)) {
2542 flush_sigqueue(¤t->pending);
2543 flush_sigqueue(¤t->signal->shared_pending);
2544 flush_signal_handlers(current, 1);
2545 sigemptyset(¤t->blocked);
2546 recalc_sigpending();
2547 }
2548 spin_unlock_irq(&unrcu_pointer(current->sighand)->siglock);
2549 }
2550
2551 /* Wake up the parent if it is waiting so that it can recheck
2552 * wait permission to the new task SID. */
2553 read_lock(&tasklist_lock);
2554 __wake_up_parent(current, unrcu_pointer(current->real_parent));
2555 read_unlock(&tasklist_lock);
2556 }
2557
2558 /* superblock security operations */
2559
selinux_sb_alloc_security(struct super_block * sb)2560 static int selinux_sb_alloc_security(struct super_block *sb)
2561 {
2562 struct superblock_security_struct *sbsec = selinux_superblock(sb);
2563
2564 mutex_init(&sbsec->lock);
2565 INIT_LIST_HEAD(&sbsec->isec_head);
2566 spin_lock_init(&sbsec->isec_lock);
2567 sbsec->sid = SECINITSID_UNLABELED;
2568 sbsec->def_sid = SECINITSID_FILE;
2569 sbsec->mntpoint_sid = SECINITSID_UNLABELED;
2570
2571 return 0;
2572 }
2573
opt_len(const char * s)2574 static inline int opt_len(const char *s)
2575 {
2576 bool open_quote = false;
2577 int len;
2578 char c;
2579
2580 for (len = 0; (c = s[len]) != '\0'; len++) {
2581 if (c == '"')
2582 open_quote = !open_quote;
2583 if (c == ',' && !open_quote)
2584 break;
2585 }
2586 return len;
2587 }
2588
selinux_sb_eat_lsm_opts(char * options,void ** mnt_opts)2589 static int selinux_sb_eat_lsm_opts(char *options, void **mnt_opts)
2590 {
2591 char *from = options;
2592 char *to = options;
2593 bool first = true;
2594 int rc;
2595
2596 while (1) {
2597 int len = opt_len(from);
2598 int token;
2599 char *arg = NULL;
2600
2601 token = match_opt_prefix(from, len, &arg);
2602
2603 if (token != Opt_error) {
2604 char *p, *q;
2605
2606 /* strip quotes */
2607 if (arg) {
2608 for (p = q = arg; p < from + len; p++) {
2609 char c = *p;
2610 if (c != '"')
2611 *q++ = c;
2612 }
2613 arg = kmemdup_nul(arg, q - arg, GFP_KERNEL);
2614 if (!arg) {
2615 rc = -ENOMEM;
2616 goto free_opt;
2617 }
2618 }
2619 rc = selinux_add_opt(token, arg, mnt_opts);
2620 kfree(arg);
2621 arg = NULL;
2622 if (unlikely(rc)) {
2623 goto free_opt;
2624 }
2625 } else {
2626 if (!first) { // copy with preceding comma
2627 from--;
2628 len++;
2629 }
2630 if (to != from)
2631 memmove(to, from, len);
2632 to += len;
2633 first = false;
2634 }
2635 if (!from[len])
2636 break;
2637 from += len + 1;
2638 }
2639 *to = '\0';
2640 return 0;
2641
2642 free_opt:
2643 if (*mnt_opts) {
2644 selinux_free_mnt_opts(*mnt_opts);
2645 *mnt_opts = NULL;
2646 }
2647 return rc;
2648 }
2649
selinux_sb_mnt_opts_compat(struct super_block * sb,void * mnt_opts)2650 static int selinux_sb_mnt_opts_compat(struct super_block *sb, void *mnt_opts)
2651 {
2652 struct selinux_mnt_opts *opts = mnt_opts;
2653 struct superblock_security_struct *sbsec = selinux_superblock(sb);
2654
2655 /*
2656 * Superblock not initialized (i.e. no options) - reject if any
2657 * options specified, otherwise accept.
2658 */
2659 if (!(sbsec->flags & SE_SBINITIALIZED))
2660 return opts ? 1 : 0;
2661
2662 /*
2663 * Superblock initialized and no options specified - reject if
2664 * superblock has any options set, otherwise accept.
2665 */
2666 if (!opts)
2667 return (sbsec->flags & SE_MNTMASK) ? 1 : 0;
2668
2669 if (opts->fscontext_sid) {
2670 if (bad_option(sbsec, FSCONTEXT_MNT, sbsec->sid,
2671 opts->fscontext_sid))
2672 return 1;
2673 }
2674 if (opts->context_sid) {
2675 if (bad_option(sbsec, CONTEXT_MNT, sbsec->mntpoint_sid,
2676 opts->context_sid))
2677 return 1;
2678 }
2679 if (opts->rootcontext_sid) {
2680 struct inode_security_struct *root_isec;
2681
2682 root_isec = backing_inode_security(sb->s_root);
2683 if (bad_option(sbsec, ROOTCONTEXT_MNT, root_isec->sid,
2684 opts->rootcontext_sid))
2685 return 1;
2686 }
2687 if (opts->defcontext_sid) {
2688 if (bad_option(sbsec, DEFCONTEXT_MNT, sbsec->def_sid,
2689 opts->defcontext_sid))
2690 return 1;
2691 }
2692 return 0;
2693 }
2694
selinux_sb_remount(struct super_block * sb,void * mnt_opts)2695 static int selinux_sb_remount(struct super_block *sb, void *mnt_opts)
2696 {
2697 struct selinux_mnt_opts *opts = mnt_opts;
2698 struct superblock_security_struct *sbsec = selinux_superblock(sb);
2699
2700 if (!(sbsec->flags & SE_SBINITIALIZED))
2701 return 0;
2702
2703 if (!opts)
2704 return 0;
2705
2706 if (opts->fscontext_sid) {
2707 if (bad_option(sbsec, FSCONTEXT_MNT, sbsec->sid,
2708 opts->fscontext_sid))
2709 goto out_bad_option;
2710 }
2711 if (opts->context_sid) {
2712 if (bad_option(sbsec, CONTEXT_MNT, sbsec->mntpoint_sid,
2713 opts->context_sid))
2714 goto out_bad_option;
2715 }
2716 if (opts->rootcontext_sid) {
2717 struct inode_security_struct *root_isec;
2718 root_isec = backing_inode_security(sb->s_root);
2719 if (bad_option(sbsec, ROOTCONTEXT_MNT, root_isec->sid,
2720 opts->rootcontext_sid))
2721 goto out_bad_option;
2722 }
2723 if (opts->defcontext_sid) {
2724 if (bad_option(sbsec, DEFCONTEXT_MNT, sbsec->def_sid,
2725 opts->defcontext_sid))
2726 goto out_bad_option;
2727 }
2728 return 0;
2729
2730 out_bad_option:
2731 pr_warn("SELinux: unable to change security options "
2732 "during remount (dev %s, type=%s)\n", sb->s_id,
2733 sb->s_type->name);
2734 return -EINVAL;
2735 }
2736
selinux_sb_kern_mount(const struct super_block * sb)2737 static int selinux_sb_kern_mount(const struct super_block *sb)
2738 {
2739 const struct cred *cred = current_cred();
2740 struct common_audit_data ad;
2741
2742 ad.type = LSM_AUDIT_DATA_DENTRY;
2743 ad.u.dentry = sb->s_root;
2744 return superblock_has_perm(cred, sb, FILESYSTEM__MOUNT, &ad);
2745 }
2746
selinux_sb_statfs(struct dentry * dentry)2747 static int selinux_sb_statfs(struct dentry *dentry)
2748 {
2749 const struct cred *cred = current_cred();
2750 struct common_audit_data ad;
2751
2752 ad.type = LSM_AUDIT_DATA_DENTRY;
2753 ad.u.dentry = dentry->d_sb->s_root;
2754 return superblock_has_perm(cred, dentry->d_sb, FILESYSTEM__GETATTR, &ad);
2755 }
2756
selinux_mount(const char * dev_name,const struct path * path,const char * type,unsigned long flags,void * data)2757 static int selinux_mount(const char *dev_name,
2758 const struct path *path,
2759 const char *type,
2760 unsigned long flags,
2761 void *data)
2762 {
2763 const struct cred *cred = current_cred();
2764
2765 if (flags & MS_REMOUNT)
2766 return superblock_has_perm(cred, path->dentry->d_sb,
2767 FILESYSTEM__REMOUNT, NULL);
2768 else
2769 return path_has_perm(cred, path, FILE__MOUNTON);
2770 }
2771
selinux_move_mount(const struct path * from_path,const struct path * to_path)2772 static int selinux_move_mount(const struct path *from_path,
2773 const struct path *to_path)
2774 {
2775 const struct cred *cred = current_cred();
2776
2777 return path_has_perm(cred, to_path, FILE__MOUNTON);
2778 }
2779
selinux_umount(struct vfsmount * mnt,int flags)2780 static int selinux_umount(struct vfsmount *mnt, int flags)
2781 {
2782 const struct cred *cred = current_cred();
2783
2784 return superblock_has_perm(cred, mnt->mnt_sb,
2785 FILESYSTEM__UNMOUNT, NULL);
2786 }
2787
selinux_fs_context_submount(struct fs_context * fc,struct super_block * reference)2788 static int selinux_fs_context_submount(struct fs_context *fc,
2789 struct super_block *reference)
2790 {
2791 const struct superblock_security_struct *sbsec = selinux_superblock(reference);
2792 struct selinux_mnt_opts *opts;
2793
2794 /*
2795 * Ensure that fc->security remains NULL when no options are set
2796 * as expected by selinux_set_mnt_opts().
2797 */
2798 if (!(sbsec->flags & (FSCONTEXT_MNT|CONTEXT_MNT|DEFCONTEXT_MNT)))
2799 return 0;
2800
2801 opts = kzalloc(sizeof(*opts), GFP_KERNEL);
2802 if (!opts)
2803 return -ENOMEM;
2804
2805 if (sbsec->flags & FSCONTEXT_MNT)
2806 opts->fscontext_sid = sbsec->sid;
2807 if (sbsec->flags & CONTEXT_MNT)
2808 opts->context_sid = sbsec->mntpoint_sid;
2809 if (sbsec->flags & DEFCONTEXT_MNT)
2810 opts->defcontext_sid = sbsec->def_sid;
2811 fc->security = opts;
2812 return 0;
2813 }
2814
selinux_fs_context_dup(struct fs_context * fc,struct fs_context * src_fc)2815 static int selinux_fs_context_dup(struct fs_context *fc,
2816 struct fs_context *src_fc)
2817 {
2818 const struct selinux_mnt_opts *src = src_fc->security;
2819
2820 if (!src)
2821 return 0;
2822
2823 fc->security = kmemdup(src, sizeof(*src), GFP_KERNEL);
2824 return fc->security ? 0 : -ENOMEM;
2825 }
2826
2827 static const struct fs_parameter_spec selinux_fs_parameters[] = {
2828 fsparam_string(CONTEXT_STR, Opt_context),
2829 fsparam_string(DEFCONTEXT_STR, Opt_defcontext),
2830 fsparam_string(FSCONTEXT_STR, Opt_fscontext),
2831 fsparam_string(ROOTCONTEXT_STR, Opt_rootcontext),
2832 fsparam_flag (SECLABEL_STR, Opt_seclabel),
2833 {}
2834 };
2835
selinux_fs_context_parse_param(struct fs_context * fc,struct fs_parameter * param)2836 static int selinux_fs_context_parse_param(struct fs_context *fc,
2837 struct fs_parameter *param)
2838 {
2839 struct fs_parse_result result;
2840 int opt;
2841
2842 opt = fs_parse(fc, selinux_fs_parameters, param, &result);
2843 if (opt < 0)
2844 return opt;
2845
2846 return selinux_add_opt(opt, param->string, &fc->security);
2847 }
2848
2849 /* inode security operations */
2850
selinux_inode_alloc_security(struct inode * inode)2851 static int selinux_inode_alloc_security(struct inode *inode)
2852 {
2853 struct inode_security_struct *isec = selinux_inode(inode);
2854 u32 sid = current_sid();
2855
2856 spin_lock_init(&isec->lock);
2857 INIT_LIST_HEAD(&isec->list);
2858 isec->inode = inode;
2859 isec->sid = SECINITSID_UNLABELED;
2860 isec->sclass = SECCLASS_FILE;
2861 isec->task_sid = sid;
2862 isec->initialized = LABEL_INVALID;
2863
2864 return 0;
2865 }
2866
selinux_inode_free_security(struct inode * inode)2867 static void selinux_inode_free_security(struct inode *inode)
2868 {
2869 inode_free_security(inode);
2870 }
2871
selinux_dentry_init_security(struct dentry * dentry,int mode,const struct qstr * name,const char ** xattr_name,void ** ctx,u32 * ctxlen)2872 static int selinux_dentry_init_security(struct dentry *dentry, int mode,
2873 const struct qstr *name,
2874 const char **xattr_name, void **ctx,
2875 u32 *ctxlen)
2876 {
2877 u32 newsid;
2878 int rc;
2879
2880 rc = selinux_determine_inode_label(selinux_cred(current_cred()),
2881 d_inode(dentry->d_parent), name,
2882 inode_mode_to_security_class(mode),
2883 &newsid);
2884 if (rc)
2885 return rc;
2886
2887 if (xattr_name)
2888 *xattr_name = XATTR_NAME_SELINUX;
2889
2890 return security_sid_to_context(newsid, (char **)ctx,
2891 ctxlen);
2892 }
2893
selinux_dentry_create_files_as(struct dentry * dentry,int mode,struct qstr * name,const struct cred * old,struct cred * new)2894 static int selinux_dentry_create_files_as(struct dentry *dentry, int mode,
2895 struct qstr *name,
2896 const struct cred *old,
2897 struct cred *new)
2898 {
2899 u32 newsid;
2900 int rc;
2901 struct task_security_struct *tsec;
2902
2903 rc = selinux_determine_inode_label(selinux_cred(old),
2904 d_inode(dentry->d_parent), name,
2905 inode_mode_to_security_class(mode),
2906 &newsid);
2907 if (rc)
2908 return rc;
2909
2910 tsec = selinux_cred(new);
2911 tsec->create_sid = newsid;
2912 return 0;
2913 }
2914
selinux_inode_init_security(struct inode * inode,struct inode * dir,const struct qstr * qstr,struct xattr * xattrs,int * xattr_count)2915 static int selinux_inode_init_security(struct inode *inode, struct inode *dir,
2916 const struct qstr *qstr,
2917 struct xattr *xattrs, int *xattr_count)
2918 {
2919 const struct task_security_struct *tsec = selinux_cred(current_cred());
2920 struct superblock_security_struct *sbsec;
2921 struct xattr *xattr = lsm_get_xattr_slot(xattrs, xattr_count);
2922 u32 newsid, clen;
2923 int rc;
2924 char *context;
2925
2926 sbsec = selinux_superblock(dir->i_sb);
2927
2928 newsid = tsec->create_sid;
2929
2930 rc = selinux_determine_inode_label(tsec, dir, qstr,
2931 inode_mode_to_security_class(inode->i_mode),
2932 &newsid);
2933 if (rc)
2934 return rc;
2935
2936 /* Possibly defer initialization to selinux_complete_init. */
2937 if (sbsec->flags & SE_SBINITIALIZED) {
2938 struct inode_security_struct *isec = selinux_inode(inode);
2939 isec->sclass = inode_mode_to_security_class(inode->i_mode);
2940 isec->sid = newsid;
2941 isec->initialized = LABEL_INITIALIZED;
2942 }
2943
2944 if (!selinux_initialized() ||
2945 !(sbsec->flags & SBLABEL_MNT))
2946 return -EOPNOTSUPP;
2947
2948 if (xattr) {
2949 rc = security_sid_to_context_force(newsid,
2950 &context, &clen);
2951 if (rc)
2952 return rc;
2953 xattr->value = context;
2954 xattr->value_len = clen;
2955 xattr->name = XATTR_SELINUX_SUFFIX;
2956 }
2957
2958 return 0;
2959 }
2960
selinux_inode_init_security_anon(struct inode * inode,const struct qstr * name,const struct inode * context_inode)2961 static int selinux_inode_init_security_anon(struct inode *inode,
2962 const struct qstr *name,
2963 const struct inode *context_inode)
2964 {
2965 const struct task_security_struct *tsec = selinux_cred(current_cred());
2966 struct common_audit_data ad;
2967 struct inode_security_struct *isec;
2968 int rc;
2969
2970 if (unlikely(!selinux_initialized()))
2971 return 0;
2972
2973 isec = selinux_inode(inode);
2974
2975 /*
2976 * We only get here once per ephemeral inode. The inode has
2977 * been initialized via inode_alloc_security but is otherwise
2978 * untouched.
2979 */
2980
2981 if (context_inode) {
2982 struct inode_security_struct *context_isec =
2983 selinux_inode(context_inode);
2984 if (context_isec->initialized != LABEL_INITIALIZED) {
2985 pr_err("SELinux: context_inode is not initialized\n");
2986 return -EACCES;
2987 }
2988
2989 isec->sclass = context_isec->sclass;
2990 isec->sid = context_isec->sid;
2991 } else {
2992 isec->sclass = SECCLASS_ANON_INODE;
2993 rc = security_transition_sid(
2994 tsec->sid, tsec->sid,
2995 isec->sclass, name, &isec->sid);
2996 if (rc)
2997 return rc;
2998 }
2999
3000 isec->initialized = LABEL_INITIALIZED;
3001 /*
3002 * Now that we've initialized security, check whether we're
3003 * allowed to actually create this type of anonymous inode.
3004 */
3005
3006 ad.type = LSM_AUDIT_DATA_ANONINODE;
3007 ad.u.anonclass = name ? (const char *)name->name : "?";
3008
3009 return avc_has_perm(tsec->sid,
3010 isec->sid,
3011 isec->sclass,
3012 FILE__CREATE,
3013 &ad);
3014 }
3015
selinux_inode_create(struct inode * dir,struct dentry * dentry,umode_t mode)3016 static int selinux_inode_create(struct inode *dir, struct dentry *dentry, umode_t mode)
3017 {
3018 return may_create(dir, dentry, SECCLASS_FILE);
3019 }
3020
selinux_inode_link(struct dentry * old_dentry,struct inode * dir,struct dentry * new_dentry)3021 static int selinux_inode_link(struct dentry *old_dentry, struct inode *dir, struct dentry *new_dentry)
3022 {
3023 return may_link(dir, old_dentry, MAY_LINK);
3024 }
3025
selinux_inode_unlink(struct inode * dir,struct dentry * dentry)3026 static int selinux_inode_unlink(struct inode *dir, struct dentry *dentry)
3027 {
3028 return may_link(dir, dentry, MAY_UNLINK);
3029 }
3030
selinux_inode_symlink(struct inode * dir,struct dentry * dentry,const char * name)3031 static int selinux_inode_symlink(struct inode *dir, struct dentry *dentry, const char *name)
3032 {
3033 return may_create(dir, dentry, SECCLASS_LNK_FILE);
3034 }
3035
selinux_inode_mkdir(struct inode * dir,struct dentry * dentry,umode_t mask)3036 static int selinux_inode_mkdir(struct inode *dir, struct dentry *dentry, umode_t mask)
3037 {
3038 return may_create(dir, dentry, SECCLASS_DIR);
3039 }
3040
selinux_inode_rmdir(struct inode * dir,struct dentry * dentry)3041 static int selinux_inode_rmdir(struct inode *dir, struct dentry *dentry)
3042 {
3043 return may_link(dir, dentry, MAY_RMDIR);
3044 }
3045
selinux_inode_mknod(struct inode * dir,struct dentry * dentry,umode_t mode,dev_t dev)3046 static int selinux_inode_mknod(struct inode *dir, struct dentry *dentry, umode_t mode, dev_t dev)
3047 {
3048 return may_create(dir, dentry, inode_mode_to_security_class(mode));
3049 }
3050
selinux_inode_rename(struct inode * old_inode,struct dentry * old_dentry,struct inode * new_inode,struct dentry * new_dentry)3051 static int selinux_inode_rename(struct inode *old_inode, struct dentry *old_dentry,
3052 struct inode *new_inode, struct dentry *new_dentry)
3053 {
3054 return may_rename(old_inode, old_dentry, new_inode, new_dentry);
3055 }
3056
selinux_inode_readlink(struct dentry * dentry)3057 static int selinux_inode_readlink(struct dentry *dentry)
3058 {
3059 const struct cred *cred = current_cred();
3060
3061 return dentry_has_perm(cred, dentry, FILE__READ);
3062 }
3063
selinux_inode_follow_link(struct dentry * dentry,struct inode * inode,bool rcu)3064 static int selinux_inode_follow_link(struct dentry *dentry, struct inode *inode,
3065 bool rcu)
3066 {
3067 const struct cred *cred = current_cred();
3068 struct common_audit_data ad;
3069 struct inode_security_struct *isec;
3070 u32 sid;
3071
3072 ad.type = LSM_AUDIT_DATA_DENTRY;
3073 ad.u.dentry = dentry;
3074 sid = cred_sid(cred);
3075 isec = inode_security_rcu(inode, rcu);
3076 if (IS_ERR(isec))
3077 return PTR_ERR(isec);
3078
3079 return avc_has_perm(sid, isec->sid, isec->sclass, FILE__READ, &ad);
3080 }
3081
audit_inode_permission(struct inode * inode,u32 perms,u32 audited,u32 denied,int result)3082 static noinline int audit_inode_permission(struct inode *inode,
3083 u32 perms, u32 audited, u32 denied,
3084 int result)
3085 {
3086 struct common_audit_data ad;
3087 struct inode_security_struct *isec = selinux_inode(inode);
3088
3089 ad.type = LSM_AUDIT_DATA_INODE;
3090 ad.u.inode = inode;
3091
3092 return slow_avc_audit(current_sid(), isec->sid, isec->sclass, perms,
3093 audited, denied, result, &ad);
3094 }
3095
selinux_inode_permission(struct inode * inode,int mask)3096 static int selinux_inode_permission(struct inode *inode, int mask)
3097 {
3098 const struct cred *cred = current_cred();
3099 u32 perms;
3100 bool from_access;
3101 bool no_block = mask & MAY_NOT_BLOCK;
3102 struct inode_security_struct *isec;
3103 u32 sid;
3104 struct av_decision avd;
3105 int rc, rc2;
3106 u32 audited, denied;
3107
3108 from_access = mask & MAY_ACCESS;
3109 mask &= (MAY_READ|MAY_WRITE|MAY_EXEC|MAY_APPEND);
3110
3111 /* No permission to check. Existence test. */
3112 if (!mask)
3113 return 0;
3114
3115 if (unlikely(IS_PRIVATE(inode)))
3116 return 0;
3117
3118 perms = file_mask_to_av(inode->i_mode, mask);
3119
3120 sid = cred_sid(cred);
3121 isec = inode_security_rcu(inode, no_block);
3122 if (IS_ERR(isec))
3123 return PTR_ERR(isec);
3124
3125 rc = avc_has_perm_noaudit(sid, isec->sid, isec->sclass, perms, 0,
3126 &avd);
3127 audited = avc_audit_required(perms, &avd, rc,
3128 from_access ? FILE__AUDIT_ACCESS : 0,
3129 &denied);
3130 if (likely(!audited))
3131 return rc;
3132
3133 rc2 = audit_inode_permission(inode, perms, audited, denied, rc);
3134 if (rc2)
3135 return rc2;
3136 return rc;
3137 }
3138
selinux_inode_setattr(struct dentry * dentry,struct iattr * iattr)3139 static int selinux_inode_setattr(struct dentry *dentry, struct iattr *iattr)
3140 {
3141 const struct cred *cred = current_cred();
3142 struct inode *inode = d_backing_inode(dentry);
3143 unsigned int ia_valid = iattr->ia_valid;
3144 __u32 av = FILE__WRITE;
3145
3146 /* ATTR_FORCE is just used for ATTR_KILL_S[UG]ID. */
3147 if (ia_valid & ATTR_FORCE) {
3148 ia_valid &= ~(ATTR_KILL_SUID | ATTR_KILL_SGID | ATTR_MODE |
3149 ATTR_FORCE);
3150 if (!ia_valid)
3151 return 0;
3152 }
3153
3154 if (ia_valid & (ATTR_MODE | ATTR_UID | ATTR_GID |
3155 ATTR_ATIME_SET | ATTR_MTIME_SET | ATTR_TIMES_SET))
3156 return dentry_has_perm(cred, dentry, FILE__SETATTR);
3157
3158 if (selinux_policycap_openperm() &&
3159 inode->i_sb->s_magic != SOCKFS_MAGIC &&
3160 (ia_valid & ATTR_SIZE) &&
3161 !(ia_valid & ATTR_FILE))
3162 av |= FILE__OPEN;
3163
3164 return dentry_has_perm(cred, dentry, av);
3165 }
3166
selinux_inode_getattr(const struct path * path)3167 static int selinux_inode_getattr(const struct path *path)
3168 {
3169 return path_has_perm(current_cred(), path, FILE__GETATTR);
3170 }
3171
has_cap_mac_admin(bool audit)3172 static bool has_cap_mac_admin(bool audit)
3173 {
3174 const struct cred *cred = current_cred();
3175 unsigned int opts = audit ? CAP_OPT_NONE : CAP_OPT_NOAUDIT;
3176
3177 if (cap_capable(cred, &init_user_ns, CAP_MAC_ADMIN, opts))
3178 return false;
3179 if (cred_has_capability(cred, CAP_MAC_ADMIN, opts, true))
3180 return false;
3181 return true;
3182 }
3183
selinux_inode_setxattr(struct mnt_idmap * idmap,struct dentry * dentry,const char * name,const void * value,size_t size,int flags)3184 static int selinux_inode_setxattr(struct mnt_idmap *idmap,
3185 struct dentry *dentry, const char *name,
3186 const void *value, size_t size, int flags)
3187 {
3188 struct inode *inode = d_backing_inode(dentry);
3189 struct inode_security_struct *isec;
3190 struct superblock_security_struct *sbsec;
3191 struct common_audit_data ad;
3192 u32 newsid, sid = current_sid();
3193 int rc = 0;
3194
3195 if (strcmp(name, XATTR_NAME_SELINUX)) {
3196 rc = cap_inode_setxattr(dentry, name, value, size, flags);
3197 if (rc)
3198 return rc;
3199
3200 /* Not an attribute we recognize, so just check the
3201 ordinary setattr permission. */
3202 return dentry_has_perm(current_cred(), dentry, FILE__SETATTR);
3203 }
3204
3205 if (!selinux_initialized())
3206 return (inode_owner_or_capable(idmap, inode) ? 0 : -EPERM);
3207
3208 sbsec = selinux_superblock(inode->i_sb);
3209 if (!(sbsec->flags & SBLABEL_MNT))
3210 return -EOPNOTSUPP;
3211
3212 if (!inode_owner_or_capable(idmap, inode))
3213 return -EPERM;
3214
3215 ad.type = LSM_AUDIT_DATA_DENTRY;
3216 ad.u.dentry = dentry;
3217
3218 isec = backing_inode_security(dentry);
3219 rc = avc_has_perm(sid, isec->sid, isec->sclass,
3220 FILE__RELABELFROM, &ad);
3221 if (rc)
3222 return rc;
3223
3224 rc = security_context_to_sid(value, size, &newsid,
3225 GFP_KERNEL);
3226 if (rc == -EINVAL) {
3227 if (!has_cap_mac_admin(true)) {
3228 struct audit_buffer *ab;
3229 size_t audit_size;
3230
3231 /* We strip a nul only if it is at the end, otherwise the
3232 * context contains a nul and we should audit that */
3233 if (value) {
3234 const char *str = value;
3235
3236 if (str[size - 1] == '\0')
3237 audit_size = size - 1;
3238 else
3239 audit_size = size;
3240 } else {
3241 audit_size = 0;
3242 }
3243 ab = audit_log_start(audit_context(),
3244 GFP_ATOMIC, AUDIT_SELINUX_ERR);
3245 if (!ab)
3246 return rc;
3247 audit_log_format(ab, "op=setxattr invalid_context=");
3248 audit_log_n_untrustedstring(ab, value, audit_size);
3249 audit_log_end(ab);
3250
3251 return rc;
3252 }
3253 rc = security_context_to_sid_force(value,
3254 size, &newsid);
3255 }
3256 if (rc)
3257 return rc;
3258
3259 rc = avc_has_perm(sid, newsid, isec->sclass,
3260 FILE__RELABELTO, &ad);
3261 if (rc)
3262 return rc;
3263
3264 rc = security_validate_transition(isec->sid, newsid,
3265 sid, isec->sclass);
3266 if (rc)
3267 return rc;
3268
3269 return avc_has_perm(newsid,
3270 sbsec->sid,
3271 SECCLASS_FILESYSTEM,
3272 FILESYSTEM__ASSOCIATE,
3273 &ad);
3274 }
3275
selinux_inode_set_acl(struct mnt_idmap * idmap,struct dentry * dentry,const char * acl_name,struct posix_acl * kacl)3276 static int selinux_inode_set_acl(struct mnt_idmap *idmap,
3277 struct dentry *dentry, const char *acl_name,
3278 struct posix_acl *kacl)
3279 {
3280 return dentry_has_perm(current_cred(), dentry, FILE__SETATTR);
3281 }
3282
selinux_inode_get_acl(struct mnt_idmap * idmap,struct dentry * dentry,const char * acl_name)3283 static int selinux_inode_get_acl(struct mnt_idmap *idmap,
3284 struct dentry *dentry, const char *acl_name)
3285 {
3286 return dentry_has_perm(current_cred(), dentry, FILE__GETATTR);
3287 }
3288
selinux_inode_remove_acl(struct mnt_idmap * idmap,struct dentry * dentry,const char * acl_name)3289 static int selinux_inode_remove_acl(struct mnt_idmap *idmap,
3290 struct dentry *dentry, const char *acl_name)
3291 {
3292 return dentry_has_perm(current_cred(), dentry, FILE__SETATTR);
3293 }
3294
selinux_inode_post_setxattr(struct dentry * dentry,const char * name,const void * value,size_t size,int flags)3295 static void selinux_inode_post_setxattr(struct dentry *dentry, const char *name,
3296 const void *value, size_t size,
3297 int flags)
3298 {
3299 struct inode *inode = d_backing_inode(dentry);
3300 struct inode_security_struct *isec;
3301 u32 newsid;
3302 int rc;
3303
3304 if (strcmp(name, XATTR_NAME_SELINUX)) {
3305 /* Not an attribute we recognize, so nothing to do. */
3306 return;
3307 }
3308
3309 if (!selinux_initialized()) {
3310 /* If we haven't even been initialized, then we can't validate
3311 * against a policy, so leave the label as invalid. It may
3312 * resolve to a valid label on the next revalidation try if
3313 * we've since initialized.
3314 */
3315 return;
3316 }
3317
3318 rc = security_context_to_sid_force(value, size,
3319 &newsid);
3320 if (rc) {
3321 pr_err("SELinux: unable to map context to SID"
3322 "for (%s, %lu), rc=%d\n",
3323 inode->i_sb->s_id, inode->i_ino, -rc);
3324 return;
3325 }
3326
3327 isec = backing_inode_security(dentry);
3328 spin_lock(&isec->lock);
3329 isec->sclass = inode_mode_to_security_class(inode->i_mode);
3330 isec->sid = newsid;
3331 isec->initialized = LABEL_INITIALIZED;
3332 spin_unlock(&isec->lock);
3333 }
3334
selinux_inode_getxattr(struct dentry * dentry,const char * name)3335 static int selinux_inode_getxattr(struct dentry *dentry, const char *name)
3336 {
3337 const struct cred *cred = current_cred();
3338
3339 return dentry_has_perm(cred, dentry, FILE__GETATTR);
3340 }
3341
selinux_inode_listxattr(struct dentry * dentry)3342 static int selinux_inode_listxattr(struct dentry *dentry)
3343 {
3344 const struct cred *cred = current_cred();
3345
3346 return dentry_has_perm(cred, dentry, FILE__GETATTR);
3347 }
3348
selinux_inode_removexattr(struct mnt_idmap * idmap,struct dentry * dentry,const char * name)3349 static int selinux_inode_removexattr(struct mnt_idmap *idmap,
3350 struct dentry *dentry, const char *name)
3351 {
3352 if (strcmp(name, XATTR_NAME_SELINUX)) {
3353 int rc = cap_inode_removexattr(idmap, dentry, name);
3354 if (rc)
3355 return rc;
3356
3357 /* Not an attribute we recognize, so just check the
3358 ordinary setattr permission. */
3359 return dentry_has_perm(current_cred(), dentry, FILE__SETATTR);
3360 }
3361
3362 if (!selinux_initialized())
3363 return 0;
3364
3365 /* No one is allowed to remove a SELinux security label.
3366 You can change the label, but all data must be labeled. */
3367 return -EACCES;
3368 }
3369
selinux_path_notify(const struct path * path,u64 mask,unsigned int obj_type)3370 static int selinux_path_notify(const struct path *path, u64 mask,
3371 unsigned int obj_type)
3372 {
3373 int ret;
3374 u32 perm;
3375
3376 struct common_audit_data ad;
3377
3378 ad.type = LSM_AUDIT_DATA_PATH;
3379 ad.u.path = *path;
3380
3381 /*
3382 * Set permission needed based on the type of mark being set.
3383 * Performs an additional check for sb watches.
3384 */
3385 switch (obj_type) {
3386 case FSNOTIFY_OBJ_TYPE_VFSMOUNT:
3387 perm = FILE__WATCH_MOUNT;
3388 break;
3389 case FSNOTIFY_OBJ_TYPE_SB:
3390 perm = FILE__WATCH_SB;
3391 ret = superblock_has_perm(current_cred(), path->dentry->d_sb,
3392 FILESYSTEM__WATCH, &ad);
3393 if (ret)
3394 return ret;
3395 break;
3396 case FSNOTIFY_OBJ_TYPE_INODE:
3397 perm = FILE__WATCH;
3398 break;
3399 default:
3400 return -EINVAL;
3401 }
3402
3403 /* blocking watches require the file:watch_with_perm permission */
3404 if (mask & (ALL_FSNOTIFY_PERM_EVENTS))
3405 perm |= FILE__WATCH_WITH_PERM;
3406
3407 /* watches on read-like events need the file:watch_reads permission */
3408 if (mask & (FS_ACCESS | FS_ACCESS_PERM | FS_CLOSE_NOWRITE))
3409 perm |= FILE__WATCH_READS;
3410
3411 return path_has_perm(current_cred(), path, perm);
3412 }
3413
3414 /*
3415 * Copy the inode security context value to the user.
3416 *
3417 * Permission check is handled by selinux_inode_getxattr hook.
3418 */
selinux_inode_getsecurity(struct mnt_idmap * idmap,struct inode * inode,const char * name,void ** buffer,bool alloc)3419 static int selinux_inode_getsecurity(struct mnt_idmap *idmap,
3420 struct inode *inode, const char *name,
3421 void **buffer, bool alloc)
3422 {
3423 u32 size;
3424 int error;
3425 char *context = NULL;
3426 struct inode_security_struct *isec;
3427
3428 /*
3429 * If we're not initialized yet, then we can't validate contexts, so
3430 * just let vfs_getxattr fall back to using the on-disk xattr.
3431 */
3432 if (!selinux_initialized() ||
3433 strcmp(name, XATTR_SELINUX_SUFFIX))
3434 return -EOPNOTSUPP;
3435
3436 /*
3437 * If the caller has CAP_MAC_ADMIN, then get the raw context
3438 * value even if it is not defined by current policy; otherwise,
3439 * use the in-core value under current policy.
3440 * Use the non-auditing forms of the permission checks since
3441 * getxattr may be called by unprivileged processes commonly
3442 * and lack of permission just means that we fall back to the
3443 * in-core context value, not a denial.
3444 */
3445 isec = inode_security(inode);
3446 if (has_cap_mac_admin(false))
3447 error = security_sid_to_context_force(isec->sid, &context,
3448 &size);
3449 else
3450 error = security_sid_to_context(isec->sid,
3451 &context, &size);
3452 if (error)
3453 return error;
3454 error = size;
3455 if (alloc) {
3456 *buffer = context;
3457 goto out_nofree;
3458 }
3459 kfree(context);
3460 out_nofree:
3461 return error;
3462 }
3463
selinux_inode_setsecurity(struct inode * inode,const char * name,const void * value,size_t size,int flags)3464 static int selinux_inode_setsecurity(struct inode *inode, const char *name,
3465 const void *value, size_t size, int flags)
3466 {
3467 struct inode_security_struct *isec = inode_security_novalidate(inode);
3468 struct superblock_security_struct *sbsec;
3469 u32 newsid;
3470 int rc;
3471
3472 if (strcmp(name, XATTR_SELINUX_SUFFIX))
3473 return -EOPNOTSUPP;
3474
3475 sbsec = selinux_superblock(inode->i_sb);
3476 if (!(sbsec->flags & SBLABEL_MNT))
3477 return -EOPNOTSUPP;
3478
3479 if (!value || !size)
3480 return -EACCES;
3481
3482 rc = security_context_to_sid(value, size, &newsid,
3483 GFP_KERNEL);
3484 if (rc)
3485 return rc;
3486
3487 spin_lock(&isec->lock);
3488 isec->sclass = inode_mode_to_security_class(inode->i_mode);
3489 isec->sid = newsid;
3490 isec->initialized = LABEL_INITIALIZED;
3491 spin_unlock(&isec->lock);
3492 return 0;
3493 }
3494
selinux_inode_listsecurity(struct inode * inode,char * buffer,size_t buffer_size)3495 static int selinux_inode_listsecurity(struct inode *inode, char *buffer, size_t buffer_size)
3496 {
3497 const int len = sizeof(XATTR_NAME_SELINUX);
3498
3499 if (!selinux_initialized())
3500 return 0;
3501
3502 if (buffer && len <= buffer_size)
3503 memcpy(buffer, XATTR_NAME_SELINUX, len);
3504 return len;
3505 }
3506
selinux_inode_getsecid(struct inode * inode,u32 * secid)3507 static void selinux_inode_getsecid(struct inode *inode, u32 *secid)
3508 {
3509 struct inode_security_struct *isec = inode_security_novalidate(inode);
3510 *secid = isec->sid;
3511 }
3512
selinux_inode_copy_up(struct dentry * src,struct cred ** new)3513 static int selinux_inode_copy_up(struct dentry *src, struct cred **new)
3514 {
3515 u32 sid;
3516 struct task_security_struct *tsec;
3517 struct cred *new_creds = *new;
3518
3519 if (new_creds == NULL) {
3520 new_creds = prepare_creds();
3521 if (!new_creds)
3522 return -ENOMEM;
3523 }
3524
3525 tsec = selinux_cred(new_creds);
3526 /* Get label from overlay inode and set it in create_sid */
3527 selinux_inode_getsecid(d_inode(src), &sid);
3528 tsec->create_sid = sid;
3529 *new = new_creds;
3530 return 0;
3531 }
3532
selinux_inode_copy_up_xattr(const char * name)3533 static int selinux_inode_copy_up_xattr(const char *name)
3534 {
3535 /* The copy_up hook above sets the initial context on an inode, but we
3536 * don't then want to overwrite it by blindly copying all the lower
3537 * xattrs up. Instead, we have to filter out SELinux-related xattrs.
3538 */
3539 if (strcmp(name, XATTR_NAME_SELINUX) == 0)
3540 return 1; /* Discard */
3541 /*
3542 * Any other attribute apart from SELINUX is not claimed, supported
3543 * by selinux.
3544 */
3545 return -EOPNOTSUPP;
3546 }
3547
3548 /* kernfs node operations */
3549
selinux_kernfs_init_security(struct kernfs_node * kn_dir,struct kernfs_node * kn)3550 static int selinux_kernfs_init_security(struct kernfs_node *kn_dir,
3551 struct kernfs_node *kn)
3552 {
3553 const struct task_security_struct *tsec = selinux_cred(current_cred());
3554 u32 parent_sid, newsid, clen;
3555 int rc;
3556 char *context;
3557
3558 rc = kernfs_xattr_get(kn_dir, XATTR_NAME_SELINUX, NULL, 0);
3559 if (rc == -ENODATA)
3560 return 0;
3561 else if (rc < 0)
3562 return rc;
3563
3564 clen = (u32)rc;
3565 context = kmalloc(clen, GFP_KERNEL);
3566 if (!context)
3567 return -ENOMEM;
3568
3569 rc = kernfs_xattr_get(kn_dir, XATTR_NAME_SELINUX, context, clen);
3570 if (rc < 0) {
3571 kfree(context);
3572 return rc;
3573 }
3574
3575 rc = security_context_to_sid(context, clen, &parent_sid,
3576 GFP_KERNEL);
3577 kfree(context);
3578 if (rc)
3579 return rc;
3580
3581 if (tsec->create_sid) {
3582 newsid = tsec->create_sid;
3583 } else {
3584 u16 secclass = inode_mode_to_security_class(kn->mode);
3585 struct qstr q;
3586
3587 q.name = kn->name;
3588 q.hash_len = hashlen_string(kn_dir, kn->name);
3589
3590 rc = security_transition_sid(tsec->sid,
3591 parent_sid, secclass, &q,
3592 &newsid);
3593 if (rc)
3594 return rc;
3595 }
3596
3597 rc = security_sid_to_context_force(newsid,
3598 &context, &clen);
3599 if (rc)
3600 return rc;
3601
3602 rc = kernfs_xattr_set(kn, XATTR_NAME_SELINUX, context, clen,
3603 XATTR_CREATE);
3604 kfree(context);
3605 return rc;
3606 }
3607
3608
3609 /* file security operations */
3610
selinux_revalidate_file_permission(struct file * file,int mask)3611 static int selinux_revalidate_file_permission(struct file *file, int mask)
3612 {
3613 const struct cred *cred = current_cred();
3614 struct inode *inode = file_inode(file);
3615
3616 /* file_mask_to_av won't add FILE__WRITE if MAY_APPEND is set */
3617 if ((file->f_flags & O_APPEND) && (mask & MAY_WRITE))
3618 mask |= MAY_APPEND;
3619
3620 return file_has_perm(cred, file,
3621 file_mask_to_av(inode->i_mode, mask));
3622 }
3623
selinux_file_permission(struct file * file,int mask)3624 static int selinux_file_permission(struct file *file, int mask)
3625 {
3626 struct inode *inode = file_inode(file);
3627 struct file_security_struct *fsec = selinux_file(file);
3628 struct inode_security_struct *isec;
3629 u32 sid = current_sid();
3630
3631 if (!mask)
3632 /* No permission to check. Existence test. */
3633 return 0;
3634
3635 isec = inode_security(inode);
3636 if (sid == fsec->sid && fsec->isid == isec->sid &&
3637 fsec->pseqno == avc_policy_seqno())
3638 /* No change since file_open check. */
3639 return 0;
3640
3641 return selinux_revalidate_file_permission(file, mask);
3642 }
3643
selinux_file_alloc_security(struct file * file)3644 static int selinux_file_alloc_security(struct file *file)
3645 {
3646 struct file_security_struct *fsec = selinux_file(file);
3647 u32 sid = current_sid();
3648
3649 fsec->sid = sid;
3650 fsec->fown_sid = sid;
3651
3652 return 0;
3653 }
3654
3655 /*
3656 * Check whether a task has the ioctl permission and cmd
3657 * operation to an inode.
3658 */
ioctl_has_perm(const struct cred * cred,struct file * file,u32 requested,u16 cmd)3659 static int ioctl_has_perm(const struct cred *cred, struct file *file,
3660 u32 requested, u16 cmd)
3661 {
3662 struct common_audit_data ad;
3663 struct file_security_struct *fsec = selinux_file(file);
3664 struct inode *inode = file_inode(file);
3665 struct inode_security_struct *isec;
3666 struct lsm_ioctlop_audit ioctl;
3667 u32 ssid = cred_sid(cred);
3668 int rc;
3669 u8 driver = cmd >> 8;
3670 u8 xperm = cmd & 0xff;
3671
3672 ad.type = LSM_AUDIT_DATA_IOCTL_OP;
3673 ad.u.op = &ioctl;
3674 ad.u.op->cmd = cmd;
3675 ad.u.op->path = file->f_path;
3676
3677 if (ssid != fsec->sid) {
3678 rc = avc_has_perm(ssid, fsec->sid,
3679 SECCLASS_FD,
3680 FD__USE,
3681 &ad);
3682 if (rc)
3683 goto out;
3684 }
3685
3686 if (unlikely(IS_PRIVATE(inode)))
3687 return 0;
3688
3689 isec = inode_security(inode);
3690 rc = avc_has_extended_perms(ssid, isec->sid, isec->sclass,
3691 requested, driver, xperm, &ad);
3692 out:
3693 return rc;
3694 }
3695
selinux_file_ioctl(struct file * file,unsigned int cmd,unsigned long arg)3696 static int selinux_file_ioctl(struct file *file, unsigned int cmd,
3697 unsigned long arg)
3698 {
3699 const struct cred *cred = current_cred();
3700 int error = 0;
3701
3702 switch (cmd) {
3703 case FIONREAD:
3704 case FIBMAP:
3705 case FIGETBSZ:
3706 case FS_IOC_GETFLAGS:
3707 case FS_IOC_GETVERSION:
3708 error = file_has_perm(cred, file, FILE__GETATTR);
3709 break;
3710
3711 case FS_IOC_SETFLAGS:
3712 case FS_IOC_SETVERSION:
3713 error = file_has_perm(cred, file, FILE__SETATTR);
3714 break;
3715
3716 /* sys_ioctl() checks */
3717 case FIONBIO:
3718 case FIOASYNC:
3719 error = file_has_perm(cred, file, 0);
3720 break;
3721
3722 case KDSKBENT:
3723 case KDSKBSENT:
3724 error = cred_has_capability(cred, CAP_SYS_TTY_CONFIG,
3725 CAP_OPT_NONE, true);
3726 break;
3727
3728 case FIOCLEX:
3729 case FIONCLEX:
3730 if (!selinux_policycap_ioctl_skip_cloexec())
3731 error = ioctl_has_perm(cred, file, FILE__IOCTL, (u16) cmd);
3732 break;
3733
3734 /* default case assumes that the command will go
3735 * to the file's ioctl() function.
3736 */
3737 default:
3738 error = ioctl_has_perm(cred, file, FILE__IOCTL, (u16) cmd);
3739 }
3740 return error;
3741 }
3742
selinux_file_ioctl_compat(struct file * file,unsigned int cmd,unsigned long arg)3743 static int selinux_file_ioctl_compat(struct file *file, unsigned int cmd,
3744 unsigned long arg)
3745 {
3746 /*
3747 * If we are in a 64-bit kernel running 32-bit userspace, we need to
3748 * make sure we don't compare 32-bit flags to 64-bit flags.
3749 */
3750 switch (cmd) {
3751 case FS_IOC32_GETFLAGS:
3752 cmd = FS_IOC_GETFLAGS;
3753 break;
3754 case FS_IOC32_SETFLAGS:
3755 cmd = FS_IOC_SETFLAGS;
3756 break;
3757 case FS_IOC32_GETVERSION:
3758 cmd = FS_IOC_GETVERSION;
3759 break;
3760 case FS_IOC32_SETVERSION:
3761 cmd = FS_IOC_SETVERSION;
3762 break;
3763 default:
3764 break;
3765 }
3766
3767 return selinux_file_ioctl(file, cmd, arg);
3768 }
3769
3770 static int default_noexec __ro_after_init;
3771
file_map_prot_check(struct file * file,unsigned long prot,int shared)3772 static int file_map_prot_check(struct file *file, unsigned long prot, int shared)
3773 {
3774 const struct cred *cred = current_cred();
3775 u32 sid = cred_sid(cred);
3776 int rc = 0;
3777
3778 if (default_noexec &&
3779 (prot & PROT_EXEC) && (!file || IS_PRIVATE(file_inode(file)) ||
3780 (!shared && (prot & PROT_WRITE)))) {
3781 /*
3782 * We are making executable an anonymous mapping or a
3783 * private file mapping that will also be writable.
3784 * This has an additional check.
3785 */
3786 rc = avc_has_perm(sid, sid, SECCLASS_PROCESS,
3787 PROCESS__EXECMEM, NULL);
3788 if (rc)
3789 goto error;
3790 }
3791
3792 if (file) {
3793 /* read access is always possible with a mapping */
3794 u32 av = FILE__READ;
3795
3796 /* write access only matters if the mapping is shared */
3797 if (shared && (prot & PROT_WRITE))
3798 av |= FILE__WRITE;
3799
3800 if (prot & PROT_EXEC)
3801 av |= FILE__EXECUTE;
3802
3803 return file_has_perm(cred, file, av);
3804 }
3805
3806 error:
3807 return rc;
3808 }
3809
selinux_mmap_addr(unsigned long addr)3810 static int selinux_mmap_addr(unsigned long addr)
3811 {
3812 int rc = 0;
3813
3814 if (addr < CONFIG_LSM_MMAP_MIN_ADDR) {
3815 u32 sid = current_sid();
3816 rc = avc_has_perm(sid, sid, SECCLASS_MEMPROTECT,
3817 MEMPROTECT__MMAP_ZERO, NULL);
3818 }
3819
3820 return rc;
3821 }
3822
selinux_mmap_file(struct file * file,unsigned long reqprot __always_unused,unsigned long prot,unsigned long flags)3823 static int selinux_mmap_file(struct file *file,
3824 unsigned long reqprot __always_unused,
3825 unsigned long prot, unsigned long flags)
3826 {
3827 struct common_audit_data ad;
3828 int rc;
3829
3830 if (file) {
3831 ad.type = LSM_AUDIT_DATA_FILE;
3832 ad.u.file = file;
3833 rc = inode_has_perm(current_cred(), file_inode(file),
3834 FILE__MAP, &ad);
3835 if (rc)
3836 return rc;
3837 }
3838
3839 return file_map_prot_check(file, prot,
3840 (flags & MAP_TYPE) == MAP_SHARED);
3841 }
3842
selinux_file_mprotect(struct vm_area_struct * vma,unsigned long reqprot __always_unused,unsigned long prot)3843 static int selinux_file_mprotect(struct vm_area_struct *vma,
3844 unsigned long reqprot __always_unused,
3845 unsigned long prot)
3846 {
3847 const struct cred *cred = current_cred();
3848 u32 sid = cred_sid(cred);
3849
3850 if (default_noexec &&
3851 (prot & PROT_EXEC) && !(vma->vm_flags & VM_EXEC)) {
3852 int rc = 0;
3853 if (vma_is_initial_heap(vma)) {
3854 rc = avc_has_perm(sid, sid, SECCLASS_PROCESS,
3855 PROCESS__EXECHEAP, NULL);
3856 } else if (!vma->vm_file && (vma_is_initial_stack(vma) ||
3857 vma_is_stack_for_current(vma))) {
3858 rc = avc_has_perm(sid, sid, SECCLASS_PROCESS,
3859 PROCESS__EXECSTACK, NULL);
3860 } else if (vma->vm_file && vma->anon_vma) {
3861 /*
3862 * We are making executable a file mapping that has
3863 * had some COW done. Since pages might have been
3864 * written, check ability to execute the possibly
3865 * modified content. This typically should only
3866 * occur for text relocations.
3867 */
3868 rc = file_has_perm(cred, vma->vm_file, FILE__EXECMOD);
3869 }
3870 if (rc)
3871 return rc;
3872 }
3873
3874 return file_map_prot_check(vma->vm_file, prot, vma->vm_flags&VM_SHARED);
3875 }
3876
selinux_file_lock(struct file * file,unsigned int cmd)3877 static int selinux_file_lock(struct file *file, unsigned int cmd)
3878 {
3879 const struct cred *cred = current_cred();
3880
3881 return file_has_perm(cred, file, FILE__LOCK);
3882 }
3883
selinux_file_fcntl(struct file * file,unsigned int cmd,unsigned long arg)3884 static int selinux_file_fcntl(struct file *file, unsigned int cmd,
3885 unsigned long arg)
3886 {
3887 const struct cred *cred = current_cred();
3888 int err = 0;
3889
3890 switch (cmd) {
3891 case F_SETFL:
3892 if ((file->f_flags & O_APPEND) && !(arg & O_APPEND)) {
3893 err = file_has_perm(cred, file, FILE__WRITE);
3894 break;
3895 }
3896 fallthrough;
3897 case F_SETOWN:
3898 case F_SETSIG:
3899 case F_GETFL:
3900 case F_GETOWN:
3901 case F_GETSIG:
3902 case F_GETOWNER_UIDS:
3903 /* Just check FD__USE permission */
3904 err = file_has_perm(cred, file, 0);
3905 break;
3906 case F_GETLK:
3907 case F_SETLK:
3908 case F_SETLKW:
3909 case F_OFD_GETLK:
3910 case F_OFD_SETLK:
3911 case F_OFD_SETLKW:
3912 #if BITS_PER_LONG == 32
3913 case F_GETLK64:
3914 case F_SETLK64:
3915 case F_SETLKW64:
3916 #endif
3917 err = file_has_perm(cred, file, FILE__LOCK);
3918 break;
3919 }
3920
3921 return err;
3922 }
3923
selinux_file_set_fowner(struct file * file)3924 static void selinux_file_set_fowner(struct file *file)
3925 {
3926 struct file_security_struct *fsec;
3927
3928 fsec = selinux_file(file);
3929 fsec->fown_sid = current_sid();
3930 }
3931
selinux_file_send_sigiotask(struct task_struct * tsk,struct fown_struct * fown,int signum)3932 static int selinux_file_send_sigiotask(struct task_struct *tsk,
3933 struct fown_struct *fown, int signum)
3934 {
3935 struct file *file;
3936 u32 sid = task_sid_obj(tsk);
3937 u32 perm;
3938 struct file_security_struct *fsec;
3939
3940 /* struct fown_struct is never outside the context of a struct file */
3941 file = container_of(fown, struct file, f_owner);
3942
3943 fsec = selinux_file(file);
3944
3945 if (!signum)
3946 perm = signal_to_av(SIGIO); /* as per send_sigio_to_task */
3947 else
3948 perm = signal_to_av(signum);
3949
3950 return avc_has_perm(fsec->fown_sid, sid,
3951 SECCLASS_PROCESS, perm, NULL);
3952 }
3953
selinux_file_receive(struct file * file)3954 static int selinux_file_receive(struct file *file)
3955 {
3956 const struct cred *cred = current_cred();
3957
3958 return file_has_perm(cred, file, file_to_av(file));
3959 }
3960
selinux_file_open(struct file * file)3961 static int selinux_file_open(struct file *file)
3962 {
3963 struct file_security_struct *fsec;
3964 struct inode_security_struct *isec;
3965
3966 fsec = selinux_file(file);
3967 isec = inode_security(file_inode(file));
3968 /*
3969 * Save inode label and policy sequence number
3970 * at open-time so that selinux_file_permission
3971 * can determine whether revalidation is necessary.
3972 * Task label is already saved in the file security
3973 * struct as its SID.
3974 */
3975 fsec->isid = isec->sid;
3976 fsec->pseqno = avc_policy_seqno();
3977 /*
3978 * Since the inode label or policy seqno may have changed
3979 * between the selinux_inode_permission check and the saving
3980 * of state above, recheck that access is still permitted.
3981 * Otherwise, access might never be revalidated against the
3982 * new inode label or new policy.
3983 * This check is not redundant - do not remove.
3984 */
3985 return file_path_has_perm(file->f_cred, file, open_file_to_av(file));
3986 }
3987
3988 /* task security operations */
3989
selinux_task_alloc(struct task_struct * task,unsigned long clone_flags)3990 static int selinux_task_alloc(struct task_struct *task,
3991 unsigned long clone_flags)
3992 {
3993 u32 sid = current_sid();
3994
3995 return avc_has_perm(sid, sid, SECCLASS_PROCESS, PROCESS__FORK, NULL);
3996 }
3997
3998 /*
3999 * prepare a new set of credentials for modification
4000 */
selinux_cred_prepare(struct cred * new,const struct cred * old,gfp_t gfp)4001 static int selinux_cred_prepare(struct cred *new, const struct cred *old,
4002 gfp_t gfp)
4003 {
4004 const struct task_security_struct *old_tsec = selinux_cred(old);
4005 struct task_security_struct *tsec = selinux_cred(new);
4006
4007 *tsec = *old_tsec;
4008 return 0;
4009 }
4010
4011 /*
4012 * transfer the SELinux data to a blank set of creds
4013 */
selinux_cred_transfer(struct cred * new,const struct cred * old)4014 static void selinux_cred_transfer(struct cred *new, const struct cred *old)
4015 {
4016 const struct task_security_struct *old_tsec = selinux_cred(old);
4017 struct task_security_struct *tsec = selinux_cred(new);
4018
4019 *tsec = *old_tsec;
4020 }
4021
selinux_cred_getsecid(const struct cred * c,u32 * secid)4022 static void selinux_cred_getsecid(const struct cred *c, u32 *secid)
4023 {
4024 *secid = cred_sid(c);
4025 }
4026
4027 /*
4028 * set the security data for a kernel service
4029 * - all the creation contexts are set to unlabelled
4030 */
selinux_kernel_act_as(struct cred * new,u32 secid)4031 static int selinux_kernel_act_as(struct cred *new, u32 secid)
4032 {
4033 struct task_security_struct *tsec = selinux_cred(new);
4034 u32 sid = current_sid();
4035 int ret;
4036
4037 ret = avc_has_perm(sid, secid,
4038 SECCLASS_KERNEL_SERVICE,
4039 KERNEL_SERVICE__USE_AS_OVERRIDE,
4040 NULL);
4041 if (ret == 0) {
4042 tsec->sid = secid;
4043 tsec->create_sid = 0;
4044 tsec->keycreate_sid = 0;
4045 tsec->sockcreate_sid = 0;
4046 }
4047 return ret;
4048 }
4049
4050 /*
4051 * set the file creation context in a security record to the same as the
4052 * objective context of the specified inode
4053 */
selinux_kernel_create_files_as(struct cred * new,struct inode * inode)4054 static int selinux_kernel_create_files_as(struct cred *new, struct inode *inode)
4055 {
4056 struct inode_security_struct *isec = inode_security(inode);
4057 struct task_security_struct *tsec = selinux_cred(new);
4058 u32 sid = current_sid();
4059 int ret;
4060
4061 ret = avc_has_perm(sid, isec->sid,
4062 SECCLASS_KERNEL_SERVICE,
4063 KERNEL_SERVICE__CREATE_FILES_AS,
4064 NULL);
4065
4066 if (ret == 0)
4067 tsec->create_sid = isec->sid;
4068 return ret;
4069 }
4070
selinux_kernel_module_request(char * kmod_name)4071 static int selinux_kernel_module_request(char *kmod_name)
4072 {
4073 struct common_audit_data ad;
4074
4075 ad.type = LSM_AUDIT_DATA_KMOD;
4076 ad.u.kmod_name = kmod_name;
4077
4078 return avc_has_perm(current_sid(), SECINITSID_KERNEL, SECCLASS_SYSTEM,
4079 SYSTEM__MODULE_REQUEST, &ad);
4080 }
4081
selinux_kernel_module_from_file(struct file * file)4082 static int selinux_kernel_module_from_file(struct file *file)
4083 {
4084 struct common_audit_data ad;
4085 struct inode_security_struct *isec;
4086 struct file_security_struct *fsec;
4087 u32 sid = current_sid();
4088 int rc;
4089
4090 /* init_module */
4091 if (file == NULL)
4092 return avc_has_perm(sid, sid, SECCLASS_SYSTEM,
4093 SYSTEM__MODULE_LOAD, NULL);
4094
4095 /* finit_module */
4096
4097 ad.type = LSM_AUDIT_DATA_FILE;
4098 ad.u.file = file;
4099
4100 fsec = selinux_file(file);
4101 if (sid != fsec->sid) {
4102 rc = avc_has_perm(sid, fsec->sid, SECCLASS_FD, FD__USE, &ad);
4103 if (rc)
4104 return rc;
4105 }
4106
4107 isec = inode_security(file_inode(file));
4108 return avc_has_perm(sid, isec->sid, SECCLASS_SYSTEM,
4109 SYSTEM__MODULE_LOAD, &ad);
4110 }
4111
selinux_kernel_read_file(struct file * file,enum kernel_read_file_id id,bool contents)4112 static int selinux_kernel_read_file(struct file *file,
4113 enum kernel_read_file_id id,
4114 bool contents)
4115 {
4116 int rc = 0;
4117
4118 switch (id) {
4119 case READING_MODULE:
4120 rc = selinux_kernel_module_from_file(contents ? file : NULL);
4121 break;
4122 default:
4123 break;
4124 }
4125
4126 return rc;
4127 }
4128
selinux_kernel_load_data(enum kernel_load_data_id id,bool contents)4129 static int selinux_kernel_load_data(enum kernel_load_data_id id, bool contents)
4130 {
4131 int rc = 0;
4132
4133 switch (id) {
4134 case LOADING_MODULE:
4135 rc = selinux_kernel_module_from_file(NULL);
4136 break;
4137 default:
4138 break;
4139 }
4140
4141 return rc;
4142 }
4143
selinux_task_setpgid(struct task_struct * p,pid_t pgid)4144 static int selinux_task_setpgid(struct task_struct *p, pid_t pgid)
4145 {
4146 return avc_has_perm(current_sid(), task_sid_obj(p), SECCLASS_PROCESS,
4147 PROCESS__SETPGID, NULL);
4148 }
4149
selinux_task_getpgid(struct task_struct * p)4150 static int selinux_task_getpgid(struct task_struct *p)
4151 {
4152 return avc_has_perm(current_sid(), task_sid_obj(p), SECCLASS_PROCESS,
4153 PROCESS__GETPGID, NULL);
4154 }
4155
selinux_task_getsid(struct task_struct * p)4156 static int selinux_task_getsid(struct task_struct *p)
4157 {
4158 return avc_has_perm(current_sid(), task_sid_obj(p), SECCLASS_PROCESS,
4159 PROCESS__GETSESSION, NULL);
4160 }
4161
selinux_current_getsecid_subj(u32 * secid)4162 static void selinux_current_getsecid_subj(u32 *secid)
4163 {
4164 *secid = current_sid();
4165 }
4166
selinux_task_getsecid_obj(struct task_struct * p,u32 * secid)4167 static void selinux_task_getsecid_obj(struct task_struct *p, u32 *secid)
4168 {
4169 *secid = task_sid_obj(p);
4170 }
4171
selinux_task_setnice(struct task_struct * p,int nice)4172 static int selinux_task_setnice(struct task_struct *p, int nice)
4173 {
4174 return avc_has_perm(current_sid(), task_sid_obj(p), SECCLASS_PROCESS,
4175 PROCESS__SETSCHED, NULL);
4176 }
4177
selinux_task_setioprio(struct task_struct * p,int ioprio)4178 static int selinux_task_setioprio(struct task_struct *p, int ioprio)
4179 {
4180 return avc_has_perm(current_sid(), task_sid_obj(p), SECCLASS_PROCESS,
4181 PROCESS__SETSCHED, NULL);
4182 }
4183
selinux_task_getioprio(struct task_struct * p)4184 static int selinux_task_getioprio(struct task_struct *p)
4185 {
4186 return avc_has_perm(current_sid(), task_sid_obj(p), SECCLASS_PROCESS,
4187 PROCESS__GETSCHED, NULL);
4188 }
4189
selinux_task_prlimit(const struct cred * cred,const struct cred * tcred,unsigned int flags)4190 static int selinux_task_prlimit(const struct cred *cred, const struct cred *tcred,
4191 unsigned int flags)
4192 {
4193 u32 av = 0;
4194
4195 if (!flags)
4196 return 0;
4197 if (flags & LSM_PRLIMIT_WRITE)
4198 av |= PROCESS__SETRLIMIT;
4199 if (flags & LSM_PRLIMIT_READ)
4200 av |= PROCESS__GETRLIMIT;
4201 return avc_has_perm(cred_sid(cred), cred_sid(tcred),
4202 SECCLASS_PROCESS, av, NULL);
4203 }
4204
selinux_task_setrlimit(struct task_struct * p,unsigned int resource,struct rlimit * new_rlim)4205 static int selinux_task_setrlimit(struct task_struct *p, unsigned int resource,
4206 struct rlimit *new_rlim)
4207 {
4208 struct rlimit *old_rlim = p->signal->rlim + resource;
4209
4210 /* Control the ability to change the hard limit (whether
4211 lowering or raising it), so that the hard limit can
4212 later be used as a safe reset point for the soft limit
4213 upon context transitions. See selinux_bprm_committing_creds. */
4214 if (old_rlim->rlim_max != new_rlim->rlim_max)
4215 return avc_has_perm(current_sid(), task_sid_obj(p),
4216 SECCLASS_PROCESS, PROCESS__SETRLIMIT, NULL);
4217
4218 return 0;
4219 }
4220
selinux_task_setscheduler(struct task_struct * p)4221 static int selinux_task_setscheduler(struct task_struct *p)
4222 {
4223 return avc_has_perm(current_sid(), task_sid_obj(p), SECCLASS_PROCESS,
4224 PROCESS__SETSCHED, NULL);
4225 }
4226
selinux_task_getscheduler(struct task_struct * p)4227 static int selinux_task_getscheduler(struct task_struct *p)
4228 {
4229 return avc_has_perm(current_sid(), task_sid_obj(p), SECCLASS_PROCESS,
4230 PROCESS__GETSCHED, NULL);
4231 }
4232
selinux_task_movememory(struct task_struct * p)4233 static int selinux_task_movememory(struct task_struct *p)
4234 {
4235 return avc_has_perm(current_sid(), task_sid_obj(p), SECCLASS_PROCESS,
4236 PROCESS__SETSCHED, NULL);
4237 }
4238
selinux_task_kill(struct task_struct * p,struct kernel_siginfo * info,int sig,const struct cred * cred)4239 static int selinux_task_kill(struct task_struct *p, struct kernel_siginfo *info,
4240 int sig, const struct cred *cred)
4241 {
4242 u32 secid;
4243 u32 perm;
4244
4245 if (!sig)
4246 perm = PROCESS__SIGNULL; /* null signal; existence test */
4247 else
4248 perm = signal_to_av(sig);
4249 if (!cred)
4250 secid = current_sid();
4251 else
4252 secid = cred_sid(cred);
4253 return avc_has_perm(secid, task_sid_obj(p), SECCLASS_PROCESS, perm, NULL);
4254 }
4255
selinux_task_to_inode(struct task_struct * p,struct inode * inode)4256 static void selinux_task_to_inode(struct task_struct *p,
4257 struct inode *inode)
4258 {
4259 struct inode_security_struct *isec = selinux_inode(inode);
4260 u32 sid = task_sid_obj(p);
4261
4262 spin_lock(&isec->lock);
4263 isec->sclass = inode_mode_to_security_class(inode->i_mode);
4264 isec->sid = sid;
4265 isec->initialized = LABEL_INITIALIZED;
4266 spin_unlock(&isec->lock);
4267 }
4268
selinux_userns_create(const struct cred * cred)4269 static int selinux_userns_create(const struct cred *cred)
4270 {
4271 u32 sid = current_sid();
4272
4273 return avc_has_perm(sid, sid, SECCLASS_USER_NAMESPACE,
4274 USER_NAMESPACE__CREATE, NULL);
4275 }
4276
4277 /* Returns error only if unable to parse addresses */
selinux_parse_skb_ipv4(struct sk_buff * skb,struct common_audit_data * ad,u8 * proto)4278 static int selinux_parse_skb_ipv4(struct sk_buff *skb,
4279 struct common_audit_data *ad, u8 *proto)
4280 {
4281 int offset, ihlen, ret = -EINVAL;
4282 struct iphdr _iph, *ih;
4283
4284 offset = skb_network_offset(skb);
4285 ih = skb_header_pointer(skb, offset, sizeof(_iph), &_iph);
4286 if (ih == NULL)
4287 goto out;
4288
4289 ihlen = ih->ihl * 4;
4290 if (ihlen < sizeof(_iph))
4291 goto out;
4292
4293 ad->u.net->v4info.saddr = ih->saddr;
4294 ad->u.net->v4info.daddr = ih->daddr;
4295 ret = 0;
4296
4297 if (proto)
4298 *proto = ih->protocol;
4299
4300 switch (ih->protocol) {
4301 case IPPROTO_TCP: {
4302 struct tcphdr _tcph, *th;
4303
4304 if (ntohs(ih->frag_off) & IP_OFFSET)
4305 break;
4306
4307 offset += ihlen;
4308 th = skb_header_pointer(skb, offset, sizeof(_tcph), &_tcph);
4309 if (th == NULL)
4310 break;
4311
4312 ad->u.net->sport = th->source;
4313 ad->u.net->dport = th->dest;
4314 break;
4315 }
4316
4317 case IPPROTO_UDP: {
4318 struct udphdr _udph, *uh;
4319
4320 if (ntohs(ih->frag_off) & IP_OFFSET)
4321 break;
4322
4323 offset += ihlen;
4324 uh = skb_header_pointer(skb, offset, sizeof(_udph), &_udph);
4325 if (uh == NULL)
4326 break;
4327
4328 ad->u.net->sport = uh->source;
4329 ad->u.net->dport = uh->dest;
4330 break;
4331 }
4332
4333 case IPPROTO_DCCP: {
4334 struct dccp_hdr _dccph, *dh;
4335
4336 if (ntohs(ih->frag_off) & IP_OFFSET)
4337 break;
4338
4339 offset += ihlen;
4340 dh = skb_header_pointer(skb, offset, sizeof(_dccph), &_dccph);
4341 if (dh == NULL)
4342 break;
4343
4344 ad->u.net->sport = dh->dccph_sport;
4345 ad->u.net->dport = dh->dccph_dport;
4346 break;
4347 }
4348
4349 #if IS_ENABLED(CONFIG_IP_SCTP)
4350 case IPPROTO_SCTP: {
4351 struct sctphdr _sctph, *sh;
4352
4353 if (ntohs(ih->frag_off) & IP_OFFSET)
4354 break;
4355
4356 offset += ihlen;
4357 sh = skb_header_pointer(skb, offset, sizeof(_sctph), &_sctph);
4358 if (sh == NULL)
4359 break;
4360
4361 ad->u.net->sport = sh->source;
4362 ad->u.net->dport = sh->dest;
4363 break;
4364 }
4365 #endif
4366 default:
4367 break;
4368 }
4369 out:
4370 return ret;
4371 }
4372
4373 #if IS_ENABLED(CONFIG_IPV6)
4374
4375 /* Returns error only if unable to parse addresses */
selinux_parse_skb_ipv6(struct sk_buff * skb,struct common_audit_data * ad,u8 * proto)4376 static int selinux_parse_skb_ipv6(struct sk_buff *skb,
4377 struct common_audit_data *ad, u8 *proto)
4378 {
4379 u8 nexthdr;
4380 int ret = -EINVAL, offset;
4381 struct ipv6hdr _ipv6h, *ip6;
4382 __be16 frag_off;
4383
4384 offset = skb_network_offset(skb);
4385 ip6 = skb_header_pointer(skb, offset, sizeof(_ipv6h), &_ipv6h);
4386 if (ip6 == NULL)
4387 goto out;
4388
4389 ad->u.net->v6info.saddr = ip6->saddr;
4390 ad->u.net->v6info.daddr = ip6->daddr;
4391 ret = 0;
4392
4393 nexthdr = ip6->nexthdr;
4394 offset += sizeof(_ipv6h);
4395 offset = ipv6_skip_exthdr(skb, offset, &nexthdr, &frag_off);
4396 if (offset < 0)
4397 goto out;
4398
4399 if (proto)
4400 *proto = nexthdr;
4401
4402 switch (nexthdr) {
4403 case IPPROTO_TCP: {
4404 struct tcphdr _tcph, *th;
4405
4406 th = skb_header_pointer(skb, offset, sizeof(_tcph), &_tcph);
4407 if (th == NULL)
4408 break;
4409
4410 ad->u.net->sport = th->source;
4411 ad->u.net->dport = th->dest;
4412 break;
4413 }
4414
4415 case IPPROTO_UDP: {
4416 struct udphdr _udph, *uh;
4417
4418 uh = skb_header_pointer(skb, offset, sizeof(_udph), &_udph);
4419 if (uh == NULL)
4420 break;
4421
4422 ad->u.net->sport = uh->source;
4423 ad->u.net->dport = uh->dest;
4424 break;
4425 }
4426
4427 case IPPROTO_DCCP: {
4428 struct dccp_hdr _dccph, *dh;
4429
4430 dh = skb_header_pointer(skb, offset, sizeof(_dccph), &_dccph);
4431 if (dh == NULL)
4432 break;
4433
4434 ad->u.net->sport = dh->dccph_sport;
4435 ad->u.net->dport = dh->dccph_dport;
4436 break;
4437 }
4438
4439 #if IS_ENABLED(CONFIG_IP_SCTP)
4440 case IPPROTO_SCTP: {
4441 struct sctphdr _sctph, *sh;
4442
4443 sh = skb_header_pointer(skb, offset, sizeof(_sctph), &_sctph);
4444 if (sh == NULL)
4445 break;
4446
4447 ad->u.net->sport = sh->source;
4448 ad->u.net->dport = sh->dest;
4449 break;
4450 }
4451 #endif
4452 /* includes fragments */
4453 default:
4454 break;
4455 }
4456 out:
4457 return ret;
4458 }
4459
4460 #endif /* IPV6 */
4461
selinux_parse_skb(struct sk_buff * skb,struct common_audit_data * ad,char ** _addrp,int src,u8 * proto)4462 static int selinux_parse_skb(struct sk_buff *skb, struct common_audit_data *ad,
4463 char **_addrp, int src, u8 *proto)
4464 {
4465 char *addrp;
4466 int ret;
4467
4468 switch (ad->u.net->family) {
4469 case PF_INET:
4470 ret = selinux_parse_skb_ipv4(skb, ad, proto);
4471 if (ret)
4472 goto parse_error;
4473 addrp = (char *)(src ? &ad->u.net->v4info.saddr :
4474 &ad->u.net->v4info.daddr);
4475 goto okay;
4476
4477 #if IS_ENABLED(CONFIG_IPV6)
4478 case PF_INET6:
4479 ret = selinux_parse_skb_ipv6(skb, ad, proto);
4480 if (ret)
4481 goto parse_error;
4482 addrp = (char *)(src ? &ad->u.net->v6info.saddr :
4483 &ad->u.net->v6info.daddr);
4484 goto okay;
4485 #endif /* IPV6 */
4486 default:
4487 addrp = NULL;
4488 goto okay;
4489 }
4490
4491 parse_error:
4492 pr_warn(
4493 "SELinux: failure in selinux_parse_skb(),"
4494 " unable to parse packet\n");
4495 return ret;
4496
4497 okay:
4498 if (_addrp)
4499 *_addrp = addrp;
4500 return 0;
4501 }
4502
4503 /**
4504 * selinux_skb_peerlbl_sid - Determine the peer label of a packet
4505 * @skb: the packet
4506 * @family: protocol family
4507 * @sid: the packet's peer label SID
4508 *
4509 * Description:
4510 * Check the various different forms of network peer labeling and determine
4511 * the peer label/SID for the packet; most of the magic actually occurs in
4512 * the security server function security_net_peersid_cmp(). The function
4513 * returns zero if the value in @sid is valid (although it may be SECSID_NULL)
4514 * or -EACCES if @sid is invalid due to inconsistencies with the different
4515 * peer labels.
4516 *
4517 */
selinux_skb_peerlbl_sid(struct sk_buff * skb,u16 family,u32 * sid)4518 static int selinux_skb_peerlbl_sid(struct sk_buff *skb, u16 family, u32 *sid)
4519 {
4520 int err;
4521 u32 xfrm_sid;
4522 u32 nlbl_sid;
4523 u32 nlbl_type;
4524
4525 err = selinux_xfrm_skb_sid(skb, &xfrm_sid);
4526 if (unlikely(err))
4527 return -EACCES;
4528 err = selinux_netlbl_skbuff_getsid(skb, family, &nlbl_type, &nlbl_sid);
4529 if (unlikely(err))
4530 return -EACCES;
4531
4532 err = security_net_peersid_resolve(nlbl_sid,
4533 nlbl_type, xfrm_sid, sid);
4534 if (unlikely(err)) {
4535 pr_warn(
4536 "SELinux: failure in selinux_skb_peerlbl_sid(),"
4537 " unable to determine packet's peer label\n");
4538 return -EACCES;
4539 }
4540
4541 return 0;
4542 }
4543
4544 /**
4545 * selinux_conn_sid - Determine the child socket label for a connection
4546 * @sk_sid: the parent socket's SID
4547 * @skb_sid: the packet's SID
4548 * @conn_sid: the resulting connection SID
4549 *
4550 * If @skb_sid is valid then the user:role:type information from @sk_sid is
4551 * combined with the MLS information from @skb_sid in order to create
4552 * @conn_sid. If @skb_sid is not valid then @conn_sid is simply a copy
4553 * of @sk_sid. Returns zero on success, negative values on failure.
4554 *
4555 */
selinux_conn_sid(u32 sk_sid,u32 skb_sid,u32 * conn_sid)4556 static int selinux_conn_sid(u32 sk_sid, u32 skb_sid, u32 *conn_sid)
4557 {
4558 int err = 0;
4559
4560 if (skb_sid != SECSID_NULL)
4561 err = security_sid_mls_copy(sk_sid, skb_sid,
4562 conn_sid);
4563 else
4564 *conn_sid = sk_sid;
4565
4566 return err;
4567 }
4568
4569 /* socket security operations */
4570
socket_sockcreate_sid(const struct task_security_struct * tsec,u16 secclass,u32 * socksid)4571 static int socket_sockcreate_sid(const struct task_security_struct *tsec,
4572 u16 secclass, u32 *socksid)
4573 {
4574 if (tsec->sockcreate_sid > SECSID_NULL) {
4575 *socksid = tsec->sockcreate_sid;
4576 return 0;
4577 }
4578
4579 return security_transition_sid(tsec->sid, tsec->sid,
4580 secclass, NULL, socksid);
4581 }
4582
sock_has_perm(struct sock * sk,u32 perms)4583 static int sock_has_perm(struct sock *sk, u32 perms)
4584 {
4585 struct sk_security_struct *sksec = sk->sk_security;
4586 struct common_audit_data ad;
4587 struct lsm_network_audit net;
4588
4589 if (sksec->sid == SECINITSID_KERNEL)
4590 return 0;
4591
4592 /*
4593 * Before POLICYDB_CAP_USERSPACE_INITIAL_CONTEXT, sockets that
4594 * inherited the kernel context from early boot used to be skipped
4595 * here, so preserve that behavior unless the capability is set.
4596 *
4597 * By setting the capability the policy signals that it is ready
4598 * for this quirk to be fixed. Note that sockets created by a kernel
4599 * thread or a usermode helper executed without a transition will
4600 * still be skipped in this check regardless of the policycap
4601 * setting.
4602 */
4603 if (!selinux_policycap_userspace_initial_context() &&
4604 sksec->sid == SECINITSID_INIT)
4605 return 0;
4606
4607 ad_net_init_from_sk(&ad, &net, sk);
4608
4609 return avc_has_perm(current_sid(), sksec->sid, sksec->sclass, perms,
4610 &ad);
4611 }
4612
selinux_socket_create(int family,int type,int protocol,int kern)4613 static int selinux_socket_create(int family, int type,
4614 int protocol, int kern)
4615 {
4616 const struct task_security_struct *tsec = selinux_cred(current_cred());
4617 u32 newsid;
4618 u16 secclass;
4619 int rc;
4620
4621 if (kern)
4622 return 0;
4623
4624 secclass = socket_type_to_security_class(family, type, protocol);
4625 rc = socket_sockcreate_sid(tsec, secclass, &newsid);
4626 if (rc)
4627 return rc;
4628
4629 return avc_has_perm(tsec->sid, newsid, secclass, SOCKET__CREATE, NULL);
4630 }
4631
selinux_socket_post_create(struct socket * sock,int family,int type,int protocol,int kern)4632 static int selinux_socket_post_create(struct socket *sock, int family,
4633 int type, int protocol, int kern)
4634 {
4635 const struct task_security_struct *tsec = selinux_cred(current_cred());
4636 struct inode_security_struct *isec = inode_security_novalidate(SOCK_INODE(sock));
4637 struct sk_security_struct *sksec;
4638 u16 sclass = socket_type_to_security_class(family, type, protocol);
4639 u32 sid = SECINITSID_KERNEL;
4640 int err = 0;
4641
4642 if (!kern) {
4643 err = socket_sockcreate_sid(tsec, sclass, &sid);
4644 if (err)
4645 return err;
4646 }
4647
4648 isec->sclass = sclass;
4649 isec->sid = sid;
4650 isec->initialized = LABEL_INITIALIZED;
4651
4652 if (sock->sk) {
4653 sksec = sock->sk->sk_security;
4654 sksec->sclass = sclass;
4655 sksec->sid = sid;
4656 /* Allows detection of the first association on this socket */
4657 if (sksec->sclass == SECCLASS_SCTP_SOCKET)
4658 sksec->sctp_assoc_state = SCTP_ASSOC_UNSET;
4659
4660 err = selinux_netlbl_socket_post_create(sock->sk, family);
4661 }
4662
4663 return err;
4664 }
4665
selinux_socket_socketpair(struct socket * socka,struct socket * sockb)4666 static int selinux_socket_socketpair(struct socket *socka,
4667 struct socket *sockb)
4668 {
4669 struct sk_security_struct *sksec_a = socka->sk->sk_security;
4670 struct sk_security_struct *sksec_b = sockb->sk->sk_security;
4671
4672 sksec_a->peer_sid = sksec_b->sid;
4673 sksec_b->peer_sid = sksec_a->sid;
4674
4675 return 0;
4676 }
4677
4678 /* Range of port numbers used to automatically bind.
4679 Need to determine whether we should perform a name_bind
4680 permission check between the socket and the port number. */
4681
selinux_socket_bind(struct socket * sock,struct sockaddr * address,int addrlen)4682 static int selinux_socket_bind(struct socket *sock, struct sockaddr *address, int addrlen)
4683 {
4684 struct sock *sk = sock->sk;
4685 struct sk_security_struct *sksec = sk->sk_security;
4686 u16 family;
4687 int err;
4688
4689 err = sock_has_perm(sk, SOCKET__BIND);
4690 if (err)
4691 goto out;
4692
4693 /* If PF_INET or PF_INET6, check name_bind permission for the port. */
4694 family = sk->sk_family;
4695 if (family == PF_INET || family == PF_INET6) {
4696 char *addrp;
4697 struct common_audit_data ad;
4698 struct lsm_network_audit net = {0,};
4699 struct sockaddr_in *addr4 = NULL;
4700 struct sockaddr_in6 *addr6 = NULL;
4701 u16 family_sa;
4702 unsigned short snum;
4703 u32 sid, node_perm;
4704
4705 /*
4706 * sctp_bindx(3) calls via selinux_sctp_bind_connect()
4707 * that validates multiple binding addresses. Because of this
4708 * need to check address->sa_family as it is possible to have
4709 * sk->sk_family = PF_INET6 with addr->sa_family = AF_INET.
4710 */
4711 if (addrlen < offsetofend(struct sockaddr, sa_family))
4712 return -EINVAL;
4713 family_sa = address->sa_family;
4714 switch (family_sa) {
4715 case AF_UNSPEC:
4716 case AF_INET:
4717 if (addrlen < sizeof(struct sockaddr_in))
4718 return -EINVAL;
4719 addr4 = (struct sockaddr_in *)address;
4720 if (family_sa == AF_UNSPEC) {
4721 if (family == PF_INET6) {
4722 /* Length check from inet6_bind_sk() */
4723 if (addrlen < SIN6_LEN_RFC2133)
4724 return -EINVAL;
4725 /* Family check from __inet6_bind() */
4726 goto err_af;
4727 }
4728 /* see __inet_bind(), we only want to allow
4729 * AF_UNSPEC if the address is INADDR_ANY
4730 */
4731 if (addr4->sin_addr.s_addr != htonl(INADDR_ANY))
4732 goto err_af;
4733 family_sa = AF_INET;
4734 }
4735 snum = ntohs(addr4->sin_port);
4736 addrp = (char *)&addr4->sin_addr.s_addr;
4737 break;
4738 case AF_INET6:
4739 if (addrlen < SIN6_LEN_RFC2133)
4740 return -EINVAL;
4741 addr6 = (struct sockaddr_in6 *)address;
4742 snum = ntohs(addr6->sin6_port);
4743 addrp = (char *)&addr6->sin6_addr.s6_addr;
4744 break;
4745 default:
4746 goto err_af;
4747 }
4748
4749 ad.type = LSM_AUDIT_DATA_NET;
4750 ad.u.net = &net;
4751 ad.u.net->sport = htons(snum);
4752 ad.u.net->family = family_sa;
4753
4754 if (snum) {
4755 int low, high;
4756
4757 inet_get_local_port_range(sock_net(sk), &low, &high);
4758
4759 if (inet_port_requires_bind_service(sock_net(sk), snum) ||
4760 snum < low || snum > high) {
4761 err = sel_netport_sid(sk->sk_protocol,
4762 snum, &sid);
4763 if (err)
4764 goto out;
4765 err = avc_has_perm(sksec->sid, sid,
4766 sksec->sclass,
4767 SOCKET__NAME_BIND, &ad);
4768 if (err)
4769 goto out;
4770 }
4771 }
4772
4773 switch (sksec->sclass) {
4774 case SECCLASS_TCP_SOCKET:
4775 node_perm = TCP_SOCKET__NODE_BIND;
4776 break;
4777
4778 case SECCLASS_UDP_SOCKET:
4779 node_perm = UDP_SOCKET__NODE_BIND;
4780 break;
4781
4782 case SECCLASS_DCCP_SOCKET:
4783 node_perm = DCCP_SOCKET__NODE_BIND;
4784 break;
4785
4786 case SECCLASS_SCTP_SOCKET:
4787 node_perm = SCTP_SOCKET__NODE_BIND;
4788 break;
4789
4790 default:
4791 node_perm = RAWIP_SOCKET__NODE_BIND;
4792 break;
4793 }
4794
4795 err = sel_netnode_sid(addrp, family_sa, &sid);
4796 if (err)
4797 goto out;
4798
4799 if (family_sa == AF_INET)
4800 ad.u.net->v4info.saddr = addr4->sin_addr.s_addr;
4801 else
4802 ad.u.net->v6info.saddr = addr6->sin6_addr;
4803
4804 err = avc_has_perm(sksec->sid, sid,
4805 sksec->sclass, node_perm, &ad);
4806 if (err)
4807 goto out;
4808 }
4809 out:
4810 return err;
4811 err_af:
4812 /* Note that SCTP services expect -EINVAL, others -EAFNOSUPPORT. */
4813 if (sksec->sclass == SECCLASS_SCTP_SOCKET)
4814 return -EINVAL;
4815 return -EAFNOSUPPORT;
4816 }
4817
4818 /* This supports connect(2) and SCTP connect services such as sctp_connectx(3)
4819 * and sctp_sendmsg(3) as described in Documentation/security/SCTP.rst
4820 */
selinux_socket_connect_helper(struct socket * sock,struct sockaddr * address,int addrlen)4821 static int selinux_socket_connect_helper(struct socket *sock,
4822 struct sockaddr *address, int addrlen)
4823 {
4824 struct sock *sk = sock->sk;
4825 struct sk_security_struct *sksec = sk->sk_security;
4826 int err;
4827
4828 err = sock_has_perm(sk, SOCKET__CONNECT);
4829 if (err)
4830 return err;
4831 if (addrlen < offsetofend(struct sockaddr, sa_family))
4832 return -EINVAL;
4833
4834 /* connect(AF_UNSPEC) has special handling, as it is a documented
4835 * way to disconnect the socket
4836 */
4837 if (address->sa_family == AF_UNSPEC)
4838 return 0;
4839
4840 /*
4841 * If a TCP, DCCP or SCTP socket, check name_connect permission
4842 * for the port.
4843 */
4844 if (sksec->sclass == SECCLASS_TCP_SOCKET ||
4845 sksec->sclass == SECCLASS_DCCP_SOCKET ||
4846 sksec->sclass == SECCLASS_SCTP_SOCKET) {
4847 struct common_audit_data ad;
4848 struct lsm_network_audit net = {0,};
4849 struct sockaddr_in *addr4 = NULL;
4850 struct sockaddr_in6 *addr6 = NULL;
4851 unsigned short snum;
4852 u32 sid, perm;
4853
4854 /* sctp_connectx(3) calls via selinux_sctp_bind_connect()
4855 * that validates multiple connect addresses. Because of this
4856 * need to check address->sa_family as it is possible to have
4857 * sk->sk_family = PF_INET6 with addr->sa_family = AF_INET.
4858 */
4859 switch (address->sa_family) {
4860 case AF_INET:
4861 addr4 = (struct sockaddr_in *)address;
4862 if (addrlen < sizeof(struct sockaddr_in))
4863 return -EINVAL;
4864 snum = ntohs(addr4->sin_port);
4865 break;
4866 case AF_INET6:
4867 addr6 = (struct sockaddr_in6 *)address;
4868 if (addrlen < SIN6_LEN_RFC2133)
4869 return -EINVAL;
4870 snum = ntohs(addr6->sin6_port);
4871 break;
4872 default:
4873 /* Note that SCTP services expect -EINVAL, whereas
4874 * others expect -EAFNOSUPPORT.
4875 */
4876 if (sksec->sclass == SECCLASS_SCTP_SOCKET)
4877 return -EINVAL;
4878 else
4879 return -EAFNOSUPPORT;
4880 }
4881
4882 err = sel_netport_sid(sk->sk_protocol, snum, &sid);
4883 if (err)
4884 return err;
4885
4886 switch (sksec->sclass) {
4887 case SECCLASS_TCP_SOCKET:
4888 perm = TCP_SOCKET__NAME_CONNECT;
4889 break;
4890 case SECCLASS_DCCP_SOCKET:
4891 perm = DCCP_SOCKET__NAME_CONNECT;
4892 break;
4893 case SECCLASS_SCTP_SOCKET:
4894 perm = SCTP_SOCKET__NAME_CONNECT;
4895 break;
4896 }
4897
4898 ad.type = LSM_AUDIT_DATA_NET;
4899 ad.u.net = &net;
4900 ad.u.net->dport = htons(snum);
4901 ad.u.net->family = address->sa_family;
4902 err = avc_has_perm(sksec->sid, sid, sksec->sclass, perm, &ad);
4903 if (err)
4904 return err;
4905 }
4906
4907 return 0;
4908 }
4909
4910 /* Supports connect(2), see comments in selinux_socket_connect_helper() */
selinux_socket_connect(struct socket * sock,struct sockaddr * address,int addrlen)4911 static int selinux_socket_connect(struct socket *sock,
4912 struct sockaddr *address, int addrlen)
4913 {
4914 int err;
4915 struct sock *sk = sock->sk;
4916
4917 err = selinux_socket_connect_helper(sock, address, addrlen);
4918 if (err)
4919 return err;
4920
4921 return selinux_netlbl_socket_connect(sk, address);
4922 }
4923
selinux_socket_listen(struct socket * sock,int backlog)4924 static int selinux_socket_listen(struct socket *sock, int backlog)
4925 {
4926 return sock_has_perm(sock->sk, SOCKET__LISTEN);
4927 }
4928
selinux_socket_accept(struct socket * sock,struct socket * newsock)4929 static int selinux_socket_accept(struct socket *sock, struct socket *newsock)
4930 {
4931 int err;
4932 struct inode_security_struct *isec;
4933 struct inode_security_struct *newisec;
4934 u16 sclass;
4935 u32 sid;
4936
4937 err = sock_has_perm(sock->sk, SOCKET__ACCEPT);
4938 if (err)
4939 return err;
4940
4941 isec = inode_security_novalidate(SOCK_INODE(sock));
4942 spin_lock(&isec->lock);
4943 sclass = isec->sclass;
4944 sid = isec->sid;
4945 spin_unlock(&isec->lock);
4946
4947 newisec = inode_security_novalidate(SOCK_INODE(newsock));
4948 newisec->sclass = sclass;
4949 newisec->sid = sid;
4950 newisec->initialized = LABEL_INITIALIZED;
4951
4952 return 0;
4953 }
4954
selinux_socket_sendmsg(struct socket * sock,struct msghdr * msg,int size)4955 static int selinux_socket_sendmsg(struct socket *sock, struct msghdr *msg,
4956 int size)
4957 {
4958 return sock_has_perm(sock->sk, SOCKET__WRITE);
4959 }
4960
selinux_socket_recvmsg(struct socket * sock,struct msghdr * msg,int size,int flags)4961 static int selinux_socket_recvmsg(struct socket *sock, struct msghdr *msg,
4962 int size, int flags)
4963 {
4964 return sock_has_perm(sock->sk, SOCKET__READ);
4965 }
4966
selinux_socket_getsockname(struct socket * sock)4967 static int selinux_socket_getsockname(struct socket *sock)
4968 {
4969 return sock_has_perm(sock->sk, SOCKET__GETATTR);
4970 }
4971
selinux_socket_getpeername(struct socket * sock)4972 static int selinux_socket_getpeername(struct socket *sock)
4973 {
4974 return sock_has_perm(sock->sk, SOCKET__GETATTR);
4975 }
4976
selinux_socket_setsockopt(struct socket * sock,int level,int optname)4977 static int selinux_socket_setsockopt(struct socket *sock, int level, int optname)
4978 {
4979 int err;
4980
4981 err = sock_has_perm(sock->sk, SOCKET__SETOPT);
4982 if (err)
4983 return err;
4984
4985 return selinux_netlbl_socket_setsockopt(sock, level, optname);
4986 }
4987
selinux_socket_getsockopt(struct socket * sock,int level,int optname)4988 static int selinux_socket_getsockopt(struct socket *sock, int level,
4989 int optname)
4990 {
4991 return sock_has_perm(sock->sk, SOCKET__GETOPT);
4992 }
4993
selinux_socket_shutdown(struct socket * sock,int how)4994 static int selinux_socket_shutdown(struct socket *sock, int how)
4995 {
4996 return sock_has_perm(sock->sk, SOCKET__SHUTDOWN);
4997 }
4998
selinux_socket_unix_stream_connect(struct sock * sock,struct sock * other,struct sock * newsk)4999 static int selinux_socket_unix_stream_connect(struct sock *sock,
5000 struct sock *other,
5001 struct sock *newsk)
5002 {
5003 struct sk_security_struct *sksec_sock = sock->sk_security;
5004 struct sk_security_struct *sksec_other = other->sk_security;
5005 struct sk_security_struct *sksec_new = newsk->sk_security;
5006 struct common_audit_data ad;
5007 struct lsm_network_audit net;
5008 int err;
5009
5010 ad_net_init_from_sk(&ad, &net, other);
5011
5012 err = avc_has_perm(sksec_sock->sid, sksec_other->sid,
5013 sksec_other->sclass,
5014 UNIX_STREAM_SOCKET__CONNECTTO, &ad);
5015 if (err)
5016 return err;
5017
5018 /* server child socket */
5019 sksec_new->peer_sid = sksec_sock->sid;
5020 err = security_sid_mls_copy(sksec_other->sid,
5021 sksec_sock->sid, &sksec_new->sid);
5022 if (err)
5023 return err;
5024
5025 /* connecting socket */
5026 sksec_sock->peer_sid = sksec_new->sid;
5027
5028 return 0;
5029 }
5030
selinux_socket_unix_may_send(struct socket * sock,struct socket * other)5031 static int selinux_socket_unix_may_send(struct socket *sock,
5032 struct socket *other)
5033 {
5034 struct sk_security_struct *ssec = sock->sk->sk_security;
5035 struct sk_security_struct *osec = other->sk->sk_security;
5036 struct common_audit_data ad;
5037 struct lsm_network_audit net;
5038
5039 ad_net_init_from_sk(&ad, &net, other->sk);
5040
5041 return avc_has_perm(ssec->sid, osec->sid, osec->sclass, SOCKET__SENDTO,
5042 &ad);
5043 }
5044
selinux_inet_sys_rcv_skb(struct net * ns,int ifindex,char * addrp,u16 family,u32 peer_sid,struct common_audit_data * ad)5045 static int selinux_inet_sys_rcv_skb(struct net *ns, int ifindex,
5046 char *addrp, u16 family, u32 peer_sid,
5047 struct common_audit_data *ad)
5048 {
5049 int err;
5050 u32 if_sid;
5051 u32 node_sid;
5052
5053 err = sel_netif_sid(ns, ifindex, &if_sid);
5054 if (err)
5055 return err;
5056 err = avc_has_perm(peer_sid, if_sid,
5057 SECCLASS_NETIF, NETIF__INGRESS, ad);
5058 if (err)
5059 return err;
5060
5061 err = sel_netnode_sid(addrp, family, &node_sid);
5062 if (err)
5063 return err;
5064 return avc_has_perm(peer_sid, node_sid,
5065 SECCLASS_NODE, NODE__RECVFROM, ad);
5066 }
5067
selinux_sock_rcv_skb_compat(struct sock * sk,struct sk_buff * skb,u16 family)5068 static int selinux_sock_rcv_skb_compat(struct sock *sk, struct sk_buff *skb,
5069 u16 family)
5070 {
5071 int err = 0;
5072 struct sk_security_struct *sksec = sk->sk_security;
5073 u32 sk_sid = sksec->sid;
5074 struct common_audit_data ad;
5075 struct lsm_network_audit net;
5076 char *addrp;
5077
5078 ad_net_init_from_iif(&ad, &net, skb->skb_iif, family);
5079 err = selinux_parse_skb(skb, &ad, &addrp, 1, NULL);
5080 if (err)
5081 return err;
5082
5083 if (selinux_secmark_enabled()) {
5084 err = avc_has_perm(sk_sid, skb->secmark, SECCLASS_PACKET,
5085 PACKET__RECV, &ad);
5086 if (err)
5087 return err;
5088 }
5089
5090 err = selinux_netlbl_sock_rcv_skb(sksec, skb, family, &ad);
5091 if (err)
5092 return err;
5093 err = selinux_xfrm_sock_rcv_skb(sksec->sid, skb, &ad);
5094
5095 return err;
5096 }
5097
selinux_socket_sock_rcv_skb(struct sock * sk,struct sk_buff * skb)5098 static int selinux_socket_sock_rcv_skb(struct sock *sk, struct sk_buff *skb)
5099 {
5100 int err, peerlbl_active, secmark_active;
5101 struct sk_security_struct *sksec = sk->sk_security;
5102 u16 family = sk->sk_family;
5103 u32 sk_sid = sksec->sid;
5104 struct common_audit_data ad;
5105 struct lsm_network_audit net;
5106 char *addrp;
5107
5108 if (family != PF_INET && family != PF_INET6)
5109 return 0;
5110
5111 /* Handle mapped IPv4 packets arriving via IPv6 sockets */
5112 if (family == PF_INET6 && skb->protocol == htons(ETH_P_IP))
5113 family = PF_INET;
5114
5115 /* If any sort of compatibility mode is enabled then handoff processing
5116 * to the selinux_sock_rcv_skb_compat() function to deal with the
5117 * special handling. We do this in an attempt to keep this function
5118 * as fast and as clean as possible. */
5119 if (!selinux_policycap_netpeer())
5120 return selinux_sock_rcv_skb_compat(sk, skb, family);
5121
5122 secmark_active = selinux_secmark_enabled();
5123 peerlbl_active = selinux_peerlbl_enabled();
5124 if (!secmark_active && !peerlbl_active)
5125 return 0;
5126
5127 ad_net_init_from_iif(&ad, &net, skb->skb_iif, family);
5128 err = selinux_parse_skb(skb, &ad, &addrp, 1, NULL);
5129 if (err)
5130 return err;
5131
5132 if (peerlbl_active) {
5133 u32 peer_sid;
5134
5135 err = selinux_skb_peerlbl_sid(skb, family, &peer_sid);
5136 if (err)
5137 return err;
5138 err = selinux_inet_sys_rcv_skb(sock_net(sk), skb->skb_iif,
5139 addrp, family, peer_sid, &ad);
5140 if (err) {
5141 selinux_netlbl_err(skb, family, err, 0);
5142 return err;
5143 }
5144 err = avc_has_perm(sk_sid, peer_sid, SECCLASS_PEER,
5145 PEER__RECV, &ad);
5146 if (err) {
5147 selinux_netlbl_err(skb, family, err, 0);
5148 return err;
5149 }
5150 }
5151
5152 if (secmark_active) {
5153 err = avc_has_perm(sk_sid, skb->secmark, SECCLASS_PACKET,
5154 PACKET__RECV, &ad);
5155 if (err)
5156 return err;
5157 }
5158
5159 return err;
5160 }
5161
selinux_socket_getpeersec_stream(struct socket * sock,sockptr_t optval,sockptr_t optlen,unsigned int len)5162 static int selinux_socket_getpeersec_stream(struct socket *sock,
5163 sockptr_t optval, sockptr_t optlen,
5164 unsigned int len)
5165 {
5166 int err = 0;
5167 char *scontext = NULL;
5168 u32 scontext_len;
5169 struct sk_security_struct *sksec = sock->sk->sk_security;
5170 u32 peer_sid = SECSID_NULL;
5171
5172 if (sksec->sclass == SECCLASS_UNIX_STREAM_SOCKET ||
5173 sksec->sclass == SECCLASS_TCP_SOCKET ||
5174 sksec->sclass == SECCLASS_SCTP_SOCKET)
5175 peer_sid = sksec->peer_sid;
5176 if (peer_sid == SECSID_NULL)
5177 return -ENOPROTOOPT;
5178
5179 err = security_sid_to_context(peer_sid, &scontext,
5180 &scontext_len);
5181 if (err)
5182 return err;
5183 if (scontext_len > len) {
5184 err = -ERANGE;
5185 goto out_len;
5186 }
5187
5188 if (copy_to_sockptr(optval, scontext, scontext_len))
5189 err = -EFAULT;
5190 out_len:
5191 if (copy_to_sockptr(optlen, &scontext_len, sizeof(scontext_len)))
5192 err = -EFAULT;
5193 kfree(scontext);
5194 return err;
5195 }
5196
selinux_socket_getpeersec_dgram(struct socket * sock,struct sk_buff * skb,u32 * secid)5197 static int selinux_socket_getpeersec_dgram(struct socket *sock, struct sk_buff *skb, u32 *secid)
5198 {
5199 u32 peer_secid = SECSID_NULL;
5200 u16 family;
5201 struct inode_security_struct *isec;
5202
5203 if (skb && skb->protocol == htons(ETH_P_IP))
5204 family = PF_INET;
5205 else if (skb && skb->protocol == htons(ETH_P_IPV6))
5206 family = PF_INET6;
5207 else if (sock)
5208 family = sock->sk->sk_family;
5209 else
5210 goto out;
5211
5212 if (sock && family == PF_UNIX) {
5213 isec = inode_security_novalidate(SOCK_INODE(sock));
5214 peer_secid = isec->sid;
5215 } else if (skb)
5216 selinux_skb_peerlbl_sid(skb, family, &peer_secid);
5217
5218 out:
5219 *secid = peer_secid;
5220 if (peer_secid == SECSID_NULL)
5221 return -EINVAL;
5222 return 0;
5223 }
5224
selinux_sk_alloc_security(struct sock * sk,int family,gfp_t priority)5225 static int selinux_sk_alloc_security(struct sock *sk, int family, gfp_t priority)
5226 {
5227 struct sk_security_struct *sksec;
5228
5229 sksec = kzalloc(sizeof(*sksec), priority);
5230 if (!sksec)
5231 return -ENOMEM;
5232
5233 sksec->peer_sid = SECINITSID_UNLABELED;
5234 sksec->sid = SECINITSID_UNLABELED;
5235 sksec->sclass = SECCLASS_SOCKET;
5236 selinux_netlbl_sk_security_reset(sksec);
5237 sk->sk_security = sksec;
5238
5239 return 0;
5240 }
5241
selinux_sk_free_security(struct sock * sk)5242 static void selinux_sk_free_security(struct sock *sk)
5243 {
5244 struct sk_security_struct *sksec = sk->sk_security;
5245
5246 sk->sk_security = NULL;
5247 selinux_netlbl_sk_security_free(sksec);
5248 kfree(sksec);
5249 }
5250
selinux_sk_clone_security(const struct sock * sk,struct sock * newsk)5251 static void selinux_sk_clone_security(const struct sock *sk, struct sock *newsk)
5252 {
5253 struct sk_security_struct *sksec = sk->sk_security;
5254 struct sk_security_struct *newsksec = newsk->sk_security;
5255
5256 newsksec->sid = sksec->sid;
5257 newsksec->peer_sid = sksec->peer_sid;
5258 newsksec->sclass = sksec->sclass;
5259
5260 selinux_netlbl_sk_security_reset(newsksec);
5261 }
5262
selinux_sk_getsecid(const struct sock * sk,u32 * secid)5263 static void selinux_sk_getsecid(const struct sock *sk, u32 *secid)
5264 {
5265 if (!sk)
5266 *secid = SECINITSID_ANY_SOCKET;
5267 else {
5268 const struct sk_security_struct *sksec = sk->sk_security;
5269
5270 *secid = sksec->sid;
5271 }
5272 }
5273
selinux_sock_graft(struct sock * sk,struct socket * parent)5274 static void selinux_sock_graft(struct sock *sk, struct socket *parent)
5275 {
5276 struct inode_security_struct *isec =
5277 inode_security_novalidate(SOCK_INODE(parent));
5278 struct sk_security_struct *sksec = sk->sk_security;
5279
5280 if (sk->sk_family == PF_INET || sk->sk_family == PF_INET6 ||
5281 sk->sk_family == PF_UNIX)
5282 isec->sid = sksec->sid;
5283 sksec->sclass = isec->sclass;
5284 }
5285
5286 /*
5287 * Determines peer_secid for the asoc and updates socket's peer label
5288 * if it's the first association on the socket.
5289 */
selinux_sctp_process_new_assoc(struct sctp_association * asoc,struct sk_buff * skb)5290 static int selinux_sctp_process_new_assoc(struct sctp_association *asoc,
5291 struct sk_buff *skb)
5292 {
5293 struct sock *sk = asoc->base.sk;
5294 u16 family = sk->sk_family;
5295 struct sk_security_struct *sksec = sk->sk_security;
5296 struct common_audit_data ad;
5297 struct lsm_network_audit net;
5298 int err;
5299
5300 /* handle mapped IPv4 packets arriving via IPv6 sockets */
5301 if (family == PF_INET6 && skb->protocol == htons(ETH_P_IP))
5302 family = PF_INET;
5303
5304 if (selinux_peerlbl_enabled()) {
5305 asoc->peer_secid = SECSID_NULL;
5306
5307 /* This will return peer_sid = SECSID_NULL if there are
5308 * no peer labels, see security_net_peersid_resolve().
5309 */
5310 err = selinux_skb_peerlbl_sid(skb, family, &asoc->peer_secid);
5311 if (err)
5312 return err;
5313
5314 if (asoc->peer_secid == SECSID_NULL)
5315 asoc->peer_secid = SECINITSID_UNLABELED;
5316 } else {
5317 asoc->peer_secid = SECINITSID_UNLABELED;
5318 }
5319
5320 if (sksec->sctp_assoc_state == SCTP_ASSOC_UNSET) {
5321 sksec->sctp_assoc_state = SCTP_ASSOC_SET;
5322
5323 /* Here as first association on socket. As the peer SID
5324 * was allowed by peer recv (and the netif/node checks),
5325 * then it is approved by policy and used as the primary
5326 * peer SID for getpeercon(3).
5327 */
5328 sksec->peer_sid = asoc->peer_secid;
5329 } else if (sksec->peer_sid != asoc->peer_secid) {
5330 /* Other association peer SIDs are checked to enforce
5331 * consistency among the peer SIDs.
5332 */
5333 ad_net_init_from_sk(&ad, &net, asoc->base.sk);
5334 err = avc_has_perm(sksec->peer_sid, asoc->peer_secid,
5335 sksec->sclass, SCTP_SOCKET__ASSOCIATION,
5336 &ad);
5337 if (err)
5338 return err;
5339 }
5340 return 0;
5341 }
5342
5343 /* Called whenever SCTP receives an INIT or COOKIE ECHO chunk. This
5344 * happens on an incoming connect(2), sctp_connectx(3) or
5345 * sctp_sendmsg(3) (with no association already present).
5346 */
selinux_sctp_assoc_request(struct sctp_association * asoc,struct sk_buff * skb)5347 static int selinux_sctp_assoc_request(struct sctp_association *asoc,
5348 struct sk_buff *skb)
5349 {
5350 struct sk_security_struct *sksec = asoc->base.sk->sk_security;
5351 u32 conn_sid;
5352 int err;
5353
5354 if (!selinux_policycap_extsockclass())
5355 return 0;
5356
5357 err = selinux_sctp_process_new_assoc(asoc, skb);
5358 if (err)
5359 return err;
5360
5361 /* Compute the MLS component for the connection and store
5362 * the information in asoc. This will be used by SCTP TCP type
5363 * sockets and peeled off connections as they cause a new
5364 * socket to be generated. selinux_sctp_sk_clone() will then
5365 * plug this into the new socket.
5366 */
5367 err = selinux_conn_sid(sksec->sid, asoc->peer_secid, &conn_sid);
5368 if (err)
5369 return err;
5370
5371 asoc->secid = conn_sid;
5372
5373 /* Set any NetLabel labels including CIPSO/CALIPSO options. */
5374 return selinux_netlbl_sctp_assoc_request(asoc, skb);
5375 }
5376
5377 /* Called when SCTP receives a COOKIE ACK chunk as the final
5378 * response to an association request (initited by us).
5379 */
selinux_sctp_assoc_established(struct sctp_association * asoc,struct sk_buff * skb)5380 static int selinux_sctp_assoc_established(struct sctp_association *asoc,
5381 struct sk_buff *skb)
5382 {
5383 struct sk_security_struct *sksec = asoc->base.sk->sk_security;
5384
5385 if (!selinux_policycap_extsockclass())
5386 return 0;
5387
5388 /* Inherit secid from the parent socket - this will be picked up
5389 * by selinux_sctp_sk_clone() if the association gets peeled off
5390 * into a new socket.
5391 */
5392 asoc->secid = sksec->sid;
5393
5394 return selinux_sctp_process_new_assoc(asoc, skb);
5395 }
5396
5397 /* Check if sctp IPv4/IPv6 addresses are valid for binding or connecting
5398 * based on their @optname.
5399 */
selinux_sctp_bind_connect(struct sock * sk,int optname,struct sockaddr * address,int addrlen)5400 static int selinux_sctp_bind_connect(struct sock *sk, int optname,
5401 struct sockaddr *address,
5402 int addrlen)
5403 {
5404 int len, err = 0, walk_size = 0;
5405 void *addr_buf;
5406 struct sockaddr *addr;
5407 struct socket *sock;
5408
5409 if (!selinux_policycap_extsockclass())
5410 return 0;
5411
5412 /* Process one or more addresses that may be IPv4 or IPv6 */
5413 sock = sk->sk_socket;
5414 addr_buf = address;
5415
5416 while (walk_size < addrlen) {
5417 if (walk_size + sizeof(sa_family_t) > addrlen)
5418 return -EINVAL;
5419
5420 addr = addr_buf;
5421 switch (addr->sa_family) {
5422 case AF_UNSPEC:
5423 case AF_INET:
5424 len = sizeof(struct sockaddr_in);
5425 break;
5426 case AF_INET6:
5427 len = sizeof(struct sockaddr_in6);
5428 break;
5429 default:
5430 return -EINVAL;
5431 }
5432
5433 if (walk_size + len > addrlen)
5434 return -EINVAL;
5435
5436 err = -EINVAL;
5437 switch (optname) {
5438 /* Bind checks */
5439 case SCTP_PRIMARY_ADDR:
5440 case SCTP_SET_PEER_PRIMARY_ADDR:
5441 case SCTP_SOCKOPT_BINDX_ADD:
5442 err = selinux_socket_bind(sock, addr, len);
5443 break;
5444 /* Connect checks */
5445 case SCTP_SOCKOPT_CONNECTX:
5446 case SCTP_PARAM_SET_PRIMARY:
5447 case SCTP_PARAM_ADD_IP:
5448 case SCTP_SENDMSG_CONNECT:
5449 err = selinux_socket_connect_helper(sock, addr, len);
5450 if (err)
5451 return err;
5452
5453 /* As selinux_sctp_bind_connect() is called by the
5454 * SCTP protocol layer, the socket is already locked,
5455 * therefore selinux_netlbl_socket_connect_locked()
5456 * is called here. The situations handled are:
5457 * sctp_connectx(3), sctp_sendmsg(3), sendmsg(2),
5458 * whenever a new IP address is added or when a new
5459 * primary address is selected.
5460 * Note that an SCTP connect(2) call happens before
5461 * the SCTP protocol layer and is handled via
5462 * selinux_socket_connect().
5463 */
5464 err = selinux_netlbl_socket_connect_locked(sk, addr);
5465 break;
5466 }
5467
5468 if (err)
5469 return err;
5470
5471 addr_buf += len;
5472 walk_size += len;
5473 }
5474
5475 return 0;
5476 }
5477
5478 /* 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)5479 static void selinux_sctp_sk_clone(struct sctp_association *asoc, struct sock *sk,
5480 struct sock *newsk)
5481 {
5482 struct sk_security_struct *sksec = sk->sk_security;
5483 struct sk_security_struct *newsksec = newsk->sk_security;
5484
5485 /* If policy does not support SECCLASS_SCTP_SOCKET then call
5486 * the non-sctp clone version.
5487 */
5488 if (!selinux_policycap_extsockclass())
5489 return selinux_sk_clone_security(sk, newsk);
5490
5491 newsksec->sid = asoc->secid;
5492 newsksec->peer_sid = asoc->peer_secid;
5493 newsksec->sclass = sksec->sclass;
5494 selinux_netlbl_sctp_sk_clone(sk, newsk);
5495 }
5496
selinux_mptcp_add_subflow(struct sock * sk,struct sock * ssk)5497 static int selinux_mptcp_add_subflow(struct sock *sk, struct sock *ssk)
5498 {
5499 struct sk_security_struct *ssksec = ssk->sk_security;
5500 struct sk_security_struct *sksec = sk->sk_security;
5501
5502 ssksec->sclass = sksec->sclass;
5503 ssksec->sid = sksec->sid;
5504
5505 /* replace the existing subflow label deleting the existing one
5506 * and re-recreating a new label using the updated context
5507 */
5508 selinux_netlbl_sk_security_free(ssksec);
5509 return selinux_netlbl_socket_post_create(ssk, ssk->sk_family);
5510 }
5511
selinux_inet_conn_request(const struct sock * sk,struct sk_buff * skb,struct request_sock * req)5512 static int selinux_inet_conn_request(const struct sock *sk, struct sk_buff *skb,
5513 struct request_sock *req)
5514 {
5515 struct sk_security_struct *sksec = sk->sk_security;
5516 int err;
5517 u16 family = req->rsk_ops->family;
5518 u32 connsid;
5519 u32 peersid;
5520
5521 err = selinux_skb_peerlbl_sid(skb, family, &peersid);
5522 if (err)
5523 return err;
5524 err = selinux_conn_sid(sksec->sid, peersid, &connsid);
5525 if (err)
5526 return err;
5527 req->secid = connsid;
5528 req->peer_secid = peersid;
5529
5530 return selinux_netlbl_inet_conn_request(req, family);
5531 }
5532
selinux_inet_csk_clone(struct sock * newsk,const struct request_sock * req)5533 static void selinux_inet_csk_clone(struct sock *newsk,
5534 const struct request_sock *req)
5535 {
5536 struct sk_security_struct *newsksec = newsk->sk_security;
5537
5538 newsksec->sid = req->secid;
5539 newsksec->peer_sid = req->peer_secid;
5540 /* NOTE: Ideally, we should also get the isec->sid for the
5541 new socket in sync, but we don't have the isec available yet.
5542 So we will wait until sock_graft to do it, by which
5543 time it will have been created and available. */
5544
5545 /* We don't need to take any sort of lock here as we are the only
5546 * thread with access to newsksec */
5547 selinux_netlbl_inet_csk_clone(newsk, req->rsk_ops->family);
5548 }
5549
selinux_inet_conn_established(struct sock * sk,struct sk_buff * skb)5550 static void selinux_inet_conn_established(struct sock *sk, struct sk_buff *skb)
5551 {
5552 u16 family = sk->sk_family;
5553 struct sk_security_struct *sksec = sk->sk_security;
5554
5555 /* handle mapped IPv4 packets arriving via IPv6 sockets */
5556 if (family == PF_INET6 && skb->protocol == htons(ETH_P_IP))
5557 family = PF_INET;
5558
5559 selinux_skb_peerlbl_sid(skb, family, &sksec->peer_sid);
5560 }
5561
selinux_secmark_relabel_packet(u32 sid)5562 static int selinux_secmark_relabel_packet(u32 sid)
5563 {
5564 const struct task_security_struct *tsec;
5565 u32 tsid;
5566
5567 tsec = selinux_cred(current_cred());
5568 tsid = tsec->sid;
5569
5570 return avc_has_perm(tsid, sid, SECCLASS_PACKET, PACKET__RELABELTO,
5571 NULL);
5572 }
5573
selinux_secmark_refcount_inc(void)5574 static void selinux_secmark_refcount_inc(void)
5575 {
5576 atomic_inc(&selinux_secmark_refcount);
5577 }
5578
selinux_secmark_refcount_dec(void)5579 static void selinux_secmark_refcount_dec(void)
5580 {
5581 atomic_dec(&selinux_secmark_refcount);
5582 }
5583
selinux_req_classify_flow(const struct request_sock * req,struct flowi_common * flic)5584 static void selinux_req_classify_flow(const struct request_sock *req,
5585 struct flowi_common *flic)
5586 {
5587 flic->flowic_secid = req->secid;
5588 }
5589
selinux_tun_dev_alloc_security(void ** security)5590 static int selinux_tun_dev_alloc_security(void **security)
5591 {
5592 struct tun_security_struct *tunsec;
5593
5594 tunsec = kzalloc(sizeof(*tunsec), GFP_KERNEL);
5595 if (!tunsec)
5596 return -ENOMEM;
5597 tunsec->sid = current_sid();
5598
5599 *security = tunsec;
5600 return 0;
5601 }
5602
selinux_tun_dev_free_security(void * security)5603 static void selinux_tun_dev_free_security(void *security)
5604 {
5605 kfree(security);
5606 }
5607
selinux_tun_dev_create(void)5608 static int selinux_tun_dev_create(void)
5609 {
5610 u32 sid = current_sid();
5611
5612 /* we aren't taking into account the "sockcreate" SID since the socket
5613 * that is being created here is not a socket in the traditional sense,
5614 * instead it is a private sock, accessible only to the kernel, and
5615 * representing a wide range of network traffic spanning multiple
5616 * connections unlike traditional sockets - check the TUN driver to
5617 * get a better understanding of why this socket is special */
5618
5619 return avc_has_perm(sid, sid, SECCLASS_TUN_SOCKET, TUN_SOCKET__CREATE,
5620 NULL);
5621 }
5622
selinux_tun_dev_attach_queue(void * security)5623 static int selinux_tun_dev_attach_queue(void *security)
5624 {
5625 struct tun_security_struct *tunsec = security;
5626
5627 return avc_has_perm(current_sid(), tunsec->sid, SECCLASS_TUN_SOCKET,
5628 TUN_SOCKET__ATTACH_QUEUE, NULL);
5629 }
5630
selinux_tun_dev_attach(struct sock * sk,void * security)5631 static int selinux_tun_dev_attach(struct sock *sk, void *security)
5632 {
5633 struct tun_security_struct *tunsec = security;
5634 struct sk_security_struct *sksec = sk->sk_security;
5635
5636 /* we don't currently perform any NetLabel based labeling here and it
5637 * isn't clear that we would want to do so anyway; while we could apply
5638 * labeling without the support of the TUN user the resulting labeled
5639 * traffic from the other end of the connection would almost certainly
5640 * cause confusion to the TUN user that had no idea network labeling
5641 * protocols were being used */
5642
5643 sksec->sid = tunsec->sid;
5644 sksec->sclass = SECCLASS_TUN_SOCKET;
5645
5646 return 0;
5647 }
5648
selinux_tun_dev_open(void * security)5649 static int selinux_tun_dev_open(void *security)
5650 {
5651 struct tun_security_struct *tunsec = security;
5652 u32 sid = current_sid();
5653 int err;
5654
5655 err = avc_has_perm(sid, tunsec->sid, SECCLASS_TUN_SOCKET,
5656 TUN_SOCKET__RELABELFROM, NULL);
5657 if (err)
5658 return err;
5659 err = avc_has_perm(sid, sid, SECCLASS_TUN_SOCKET,
5660 TUN_SOCKET__RELABELTO, NULL);
5661 if (err)
5662 return err;
5663 tunsec->sid = sid;
5664
5665 return 0;
5666 }
5667
5668 #ifdef CONFIG_NETFILTER
5669
selinux_ip_forward(void * priv,struct sk_buff * skb,const struct nf_hook_state * state)5670 static unsigned int selinux_ip_forward(void *priv, struct sk_buff *skb,
5671 const struct nf_hook_state *state)
5672 {
5673 int ifindex;
5674 u16 family;
5675 char *addrp;
5676 u32 peer_sid;
5677 struct common_audit_data ad;
5678 struct lsm_network_audit net;
5679 int secmark_active, peerlbl_active;
5680
5681 if (!selinux_policycap_netpeer())
5682 return NF_ACCEPT;
5683
5684 secmark_active = selinux_secmark_enabled();
5685 peerlbl_active = selinux_peerlbl_enabled();
5686 if (!secmark_active && !peerlbl_active)
5687 return NF_ACCEPT;
5688
5689 family = state->pf;
5690 if (selinux_skb_peerlbl_sid(skb, family, &peer_sid) != 0)
5691 return NF_DROP;
5692
5693 ifindex = state->in->ifindex;
5694 ad_net_init_from_iif(&ad, &net, ifindex, family);
5695 if (selinux_parse_skb(skb, &ad, &addrp, 1, NULL) != 0)
5696 return NF_DROP;
5697
5698 if (peerlbl_active) {
5699 int err;
5700
5701 err = selinux_inet_sys_rcv_skb(state->net, ifindex,
5702 addrp, family, peer_sid, &ad);
5703 if (err) {
5704 selinux_netlbl_err(skb, family, err, 1);
5705 return NF_DROP;
5706 }
5707 }
5708
5709 if (secmark_active)
5710 if (avc_has_perm(peer_sid, skb->secmark,
5711 SECCLASS_PACKET, PACKET__FORWARD_IN, &ad))
5712 return NF_DROP;
5713
5714 if (netlbl_enabled())
5715 /* we do this in the FORWARD path and not the POST_ROUTING
5716 * path because we want to make sure we apply the necessary
5717 * labeling before IPsec is applied so we can leverage AH
5718 * protection */
5719 if (selinux_netlbl_skbuff_setsid(skb, family, peer_sid) != 0)
5720 return NF_DROP;
5721
5722 return NF_ACCEPT;
5723 }
5724
selinux_ip_output(void * priv,struct sk_buff * skb,const struct nf_hook_state * state)5725 static unsigned int selinux_ip_output(void *priv, struct sk_buff *skb,
5726 const struct nf_hook_state *state)
5727 {
5728 struct sock *sk;
5729 u32 sid;
5730
5731 if (!netlbl_enabled())
5732 return NF_ACCEPT;
5733
5734 /* we do this in the LOCAL_OUT path and not the POST_ROUTING path
5735 * because we want to make sure we apply the necessary labeling
5736 * before IPsec is applied so we can leverage AH protection */
5737 sk = skb->sk;
5738 if (sk) {
5739 struct sk_security_struct *sksec;
5740
5741 if (sk_listener(sk))
5742 /* if the socket is the listening state then this
5743 * packet is a SYN-ACK packet which means it needs to
5744 * be labeled based on the connection/request_sock and
5745 * not the parent socket. unfortunately, we can't
5746 * lookup the request_sock yet as it isn't queued on
5747 * the parent socket until after the SYN-ACK is sent.
5748 * the "solution" is to simply pass the packet as-is
5749 * as any IP option based labeling should be copied
5750 * from the initial connection request (in the IP
5751 * layer). it is far from ideal, but until we get a
5752 * security label in the packet itself this is the
5753 * best we can do. */
5754 return NF_ACCEPT;
5755
5756 /* standard practice, label using the parent socket */
5757 sksec = sk->sk_security;
5758 sid = sksec->sid;
5759 } else
5760 sid = SECINITSID_KERNEL;
5761 if (selinux_netlbl_skbuff_setsid(skb, state->pf, sid) != 0)
5762 return NF_DROP;
5763
5764 return NF_ACCEPT;
5765 }
5766
5767
selinux_ip_postroute_compat(struct sk_buff * skb,const struct nf_hook_state * state)5768 static unsigned int selinux_ip_postroute_compat(struct sk_buff *skb,
5769 const struct nf_hook_state *state)
5770 {
5771 struct sock *sk;
5772 struct sk_security_struct *sksec;
5773 struct common_audit_data ad;
5774 struct lsm_network_audit net;
5775 u8 proto = 0;
5776
5777 sk = skb_to_full_sk(skb);
5778 if (sk == NULL)
5779 return NF_ACCEPT;
5780 sksec = sk->sk_security;
5781
5782 ad_net_init_from_iif(&ad, &net, state->out->ifindex, state->pf);
5783 if (selinux_parse_skb(skb, &ad, NULL, 0, &proto))
5784 return NF_DROP;
5785
5786 if (selinux_secmark_enabled())
5787 if (avc_has_perm(sksec->sid, skb->secmark,
5788 SECCLASS_PACKET, PACKET__SEND, &ad))
5789 return NF_DROP_ERR(-ECONNREFUSED);
5790
5791 if (selinux_xfrm_postroute_last(sksec->sid, skb, &ad, proto))
5792 return NF_DROP_ERR(-ECONNREFUSED);
5793
5794 return NF_ACCEPT;
5795 }
5796
selinux_ip_postroute(void * priv,struct sk_buff * skb,const struct nf_hook_state * state)5797 static unsigned int selinux_ip_postroute(void *priv,
5798 struct sk_buff *skb,
5799 const struct nf_hook_state *state)
5800 {
5801 u16 family;
5802 u32 secmark_perm;
5803 u32 peer_sid;
5804 int ifindex;
5805 struct sock *sk;
5806 struct common_audit_data ad;
5807 struct lsm_network_audit net;
5808 char *addrp;
5809 int secmark_active, peerlbl_active;
5810
5811 /* If any sort of compatibility mode is enabled then handoff processing
5812 * to the selinux_ip_postroute_compat() function to deal with the
5813 * special handling. We do this in an attempt to keep this function
5814 * as fast and as clean as possible. */
5815 if (!selinux_policycap_netpeer())
5816 return selinux_ip_postroute_compat(skb, state);
5817
5818 secmark_active = selinux_secmark_enabled();
5819 peerlbl_active = selinux_peerlbl_enabled();
5820 if (!secmark_active && !peerlbl_active)
5821 return NF_ACCEPT;
5822
5823 sk = skb_to_full_sk(skb);
5824
5825 #ifdef CONFIG_XFRM
5826 /* If skb->dst->xfrm is non-NULL then the packet is undergoing an IPsec
5827 * packet transformation so allow the packet to pass without any checks
5828 * since we'll have another chance to perform access control checks
5829 * when the packet is on it's final way out.
5830 * NOTE: there appear to be some IPv6 multicast cases where skb->dst
5831 * is NULL, in this case go ahead and apply access control.
5832 * NOTE: if this is a local socket (skb->sk != NULL) that is in the
5833 * TCP listening state we cannot wait until the XFRM processing
5834 * is done as we will miss out on the SA label if we do;
5835 * unfortunately, this means more work, but it is only once per
5836 * connection. */
5837 if (skb_dst(skb) != NULL && skb_dst(skb)->xfrm != NULL &&
5838 !(sk && sk_listener(sk)))
5839 return NF_ACCEPT;
5840 #endif
5841
5842 family = state->pf;
5843 if (sk == NULL) {
5844 /* Without an associated socket the packet is either coming
5845 * from the kernel or it is being forwarded; check the packet
5846 * to determine which and if the packet is being forwarded
5847 * query the packet directly to determine the security label. */
5848 if (skb->skb_iif) {
5849 secmark_perm = PACKET__FORWARD_OUT;
5850 if (selinux_skb_peerlbl_sid(skb, family, &peer_sid))
5851 return NF_DROP;
5852 } else {
5853 secmark_perm = PACKET__SEND;
5854 peer_sid = SECINITSID_KERNEL;
5855 }
5856 } else if (sk_listener(sk)) {
5857 /* Locally generated packet but the associated socket is in the
5858 * listening state which means this is a SYN-ACK packet. In
5859 * this particular case the correct security label is assigned
5860 * to the connection/request_sock but unfortunately we can't
5861 * query the request_sock as it isn't queued on the parent
5862 * socket until after the SYN-ACK packet is sent; the only
5863 * viable choice is to regenerate the label like we do in
5864 * selinux_inet_conn_request(). See also selinux_ip_output()
5865 * for similar problems. */
5866 u32 skb_sid;
5867 struct sk_security_struct *sksec;
5868
5869 sksec = sk->sk_security;
5870 if (selinux_skb_peerlbl_sid(skb, family, &skb_sid))
5871 return NF_DROP;
5872 /* At this point, if the returned skb peerlbl is SECSID_NULL
5873 * and the packet has been through at least one XFRM
5874 * transformation then we must be dealing with the "final"
5875 * form of labeled IPsec packet; since we've already applied
5876 * all of our access controls on this packet we can safely
5877 * pass the packet. */
5878 if (skb_sid == SECSID_NULL) {
5879 switch (family) {
5880 case PF_INET:
5881 if (IPCB(skb)->flags & IPSKB_XFRM_TRANSFORMED)
5882 return NF_ACCEPT;
5883 break;
5884 case PF_INET6:
5885 if (IP6CB(skb)->flags & IP6SKB_XFRM_TRANSFORMED)
5886 return NF_ACCEPT;
5887 break;
5888 default:
5889 return NF_DROP_ERR(-ECONNREFUSED);
5890 }
5891 }
5892 if (selinux_conn_sid(sksec->sid, skb_sid, &peer_sid))
5893 return NF_DROP;
5894 secmark_perm = PACKET__SEND;
5895 } else {
5896 /* Locally generated packet, fetch the security label from the
5897 * associated socket. */
5898 struct sk_security_struct *sksec = sk->sk_security;
5899 peer_sid = sksec->sid;
5900 secmark_perm = PACKET__SEND;
5901 }
5902
5903 ifindex = state->out->ifindex;
5904 ad_net_init_from_iif(&ad, &net, ifindex, family);
5905 if (selinux_parse_skb(skb, &ad, &addrp, 0, NULL))
5906 return NF_DROP;
5907
5908 if (secmark_active)
5909 if (avc_has_perm(peer_sid, skb->secmark,
5910 SECCLASS_PACKET, secmark_perm, &ad))
5911 return NF_DROP_ERR(-ECONNREFUSED);
5912
5913 if (peerlbl_active) {
5914 u32 if_sid;
5915 u32 node_sid;
5916
5917 if (sel_netif_sid(state->net, ifindex, &if_sid))
5918 return NF_DROP;
5919 if (avc_has_perm(peer_sid, if_sid,
5920 SECCLASS_NETIF, NETIF__EGRESS, &ad))
5921 return NF_DROP_ERR(-ECONNREFUSED);
5922
5923 if (sel_netnode_sid(addrp, family, &node_sid))
5924 return NF_DROP;
5925 if (avc_has_perm(peer_sid, node_sid,
5926 SECCLASS_NODE, NODE__SENDTO, &ad))
5927 return NF_DROP_ERR(-ECONNREFUSED);
5928 }
5929
5930 return NF_ACCEPT;
5931 }
5932 #endif /* CONFIG_NETFILTER */
5933
selinux_netlink_send(struct sock * sk,struct sk_buff * skb)5934 static int selinux_netlink_send(struct sock *sk, struct sk_buff *skb)
5935 {
5936 int rc = 0;
5937 unsigned int msg_len;
5938 unsigned int data_len = skb->len;
5939 unsigned char *data = skb->data;
5940 struct nlmsghdr *nlh;
5941 struct sk_security_struct *sksec = sk->sk_security;
5942 u16 sclass = sksec->sclass;
5943 u32 perm;
5944
5945 while (data_len >= nlmsg_total_size(0)) {
5946 nlh = (struct nlmsghdr *)data;
5947
5948 /* NOTE: the nlmsg_len field isn't reliably set by some netlink
5949 * users which means we can't reject skb's with bogus
5950 * length fields; our solution is to follow what
5951 * netlink_rcv_skb() does and simply skip processing at
5952 * messages with length fields that are clearly junk
5953 */
5954 if (nlh->nlmsg_len < NLMSG_HDRLEN || nlh->nlmsg_len > data_len)
5955 return 0;
5956
5957 rc = selinux_nlmsg_lookup(sclass, nlh->nlmsg_type, &perm);
5958 if (rc == 0) {
5959 rc = sock_has_perm(sk, perm);
5960 if (rc)
5961 return rc;
5962 } else if (rc == -EINVAL) {
5963 /* -EINVAL is a missing msg/perm mapping */
5964 pr_warn_ratelimited("SELinux: unrecognized netlink"
5965 " message: protocol=%hu nlmsg_type=%hu sclass=%s"
5966 " pid=%d comm=%s\n",
5967 sk->sk_protocol, nlh->nlmsg_type,
5968 secclass_map[sclass - 1].name,
5969 task_pid_nr(current), current->comm);
5970 if (enforcing_enabled() &&
5971 !security_get_allow_unknown())
5972 return rc;
5973 rc = 0;
5974 } else if (rc == -ENOENT) {
5975 /* -ENOENT is a missing socket/class mapping, ignore */
5976 rc = 0;
5977 } else {
5978 return rc;
5979 }
5980
5981 /* move to the next message after applying netlink padding */
5982 msg_len = NLMSG_ALIGN(nlh->nlmsg_len);
5983 if (msg_len >= data_len)
5984 return 0;
5985 data_len -= msg_len;
5986 data += msg_len;
5987 }
5988
5989 return rc;
5990 }
5991
ipc_init_security(struct ipc_security_struct * isec,u16 sclass)5992 static void ipc_init_security(struct ipc_security_struct *isec, u16 sclass)
5993 {
5994 isec->sclass = sclass;
5995 isec->sid = current_sid();
5996 }
5997
ipc_has_perm(struct kern_ipc_perm * ipc_perms,u32 perms)5998 static int ipc_has_perm(struct kern_ipc_perm *ipc_perms,
5999 u32 perms)
6000 {
6001 struct ipc_security_struct *isec;
6002 struct common_audit_data ad;
6003 u32 sid = current_sid();
6004
6005 isec = selinux_ipc(ipc_perms);
6006
6007 ad.type = LSM_AUDIT_DATA_IPC;
6008 ad.u.ipc_id = ipc_perms->key;
6009
6010 return avc_has_perm(sid, isec->sid, isec->sclass, perms, &ad);
6011 }
6012
selinux_msg_msg_alloc_security(struct msg_msg * msg)6013 static int selinux_msg_msg_alloc_security(struct msg_msg *msg)
6014 {
6015 struct msg_security_struct *msec;
6016
6017 msec = selinux_msg_msg(msg);
6018 msec->sid = SECINITSID_UNLABELED;
6019
6020 return 0;
6021 }
6022
6023 /* message queue security operations */
selinux_msg_queue_alloc_security(struct kern_ipc_perm * msq)6024 static int selinux_msg_queue_alloc_security(struct kern_ipc_perm *msq)
6025 {
6026 struct ipc_security_struct *isec;
6027 struct common_audit_data ad;
6028 u32 sid = current_sid();
6029
6030 isec = selinux_ipc(msq);
6031 ipc_init_security(isec, SECCLASS_MSGQ);
6032
6033 ad.type = LSM_AUDIT_DATA_IPC;
6034 ad.u.ipc_id = msq->key;
6035
6036 return avc_has_perm(sid, isec->sid, SECCLASS_MSGQ,
6037 MSGQ__CREATE, &ad);
6038 }
6039
selinux_msg_queue_associate(struct kern_ipc_perm * msq,int msqflg)6040 static int selinux_msg_queue_associate(struct kern_ipc_perm *msq, int msqflg)
6041 {
6042 struct ipc_security_struct *isec;
6043 struct common_audit_data ad;
6044 u32 sid = current_sid();
6045
6046 isec = selinux_ipc(msq);
6047
6048 ad.type = LSM_AUDIT_DATA_IPC;
6049 ad.u.ipc_id = msq->key;
6050
6051 return avc_has_perm(sid, isec->sid, SECCLASS_MSGQ,
6052 MSGQ__ASSOCIATE, &ad);
6053 }
6054
selinux_msg_queue_msgctl(struct kern_ipc_perm * msq,int cmd)6055 static int selinux_msg_queue_msgctl(struct kern_ipc_perm *msq, int cmd)
6056 {
6057 u32 perms;
6058
6059 switch (cmd) {
6060 case IPC_INFO:
6061 case MSG_INFO:
6062 /* No specific object, just general system-wide information. */
6063 return avc_has_perm(current_sid(), SECINITSID_KERNEL,
6064 SECCLASS_SYSTEM, SYSTEM__IPC_INFO, NULL);
6065 case IPC_STAT:
6066 case MSG_STAT:
6067 case MSG_STAT_ANY:
6068 perms = MSGQ__GETATTR | MSGQ__ASSOCIATE;
6069 break;
6070 case IPC_SET:
6071 perms = MSGQ__SETATTR;
6072 break;
6073 case IPC_RMID:
6074 perms = MSGQ__DESTROY;
6075 break;
6076 default:
6077 return 0;
6078 }
6079
6080 return ipc_has_perm(msq, perms);
6081 }
6082
selinux_msg_queue_msgsnd(struct kern_ipc_perm * msq,struct msg_msg * msg,int msqflg)6083 static int selinux_msg_queue_msgsnd(struct kern_ipc_perm *msq, struct msg_msg *msg, int msqflg)
6084 {
6085 struct ipc_security_struct *isec;
6086 struct msg_security_struct *msec;
6087 struct common_audit_data ad;
6088 u32 sid = current_sid();
6089 int rc;
6090
6091 isec = selinux_ipc(msq);
6092 msec = selinux_msg_msg(msg);
6093
6094 /*
6095 * First time through, need to assign label to the message
6096 */
6097 if (msec->sid == SECINITSID_UNLABELED) {
6098 /*
6099 * Compute new sid based on current process and
6100 * message queue this message will be stored in
6101 */
6102 rc = security_transition_sid(sid, isec->sid,
6103 SECCLASS_MSG, NULL, &msec->sid);
6104 if (rc)
6105 return rc;
6106 }
6107
6108 ad.type = LSM_AUDIT_DATA_IPC;
6109 ad.u.ipc_id = msq->key;
6110
6111 /* Can this process write to the queue? */
6112 rc = avc_has_perm(sid, isec->sid, SECCLASS_MSGQ,
6113 MSGQ__WRITE, &ad);
6114 if (!rc)
6115 /* Can this process send the message */
6116 rc = avc_has_perm(sid, msec->sid, SECCLASS_MSG,
6117 MSG__SEND, &ad);
6118 if (!rc)
6119 /* Can the message be put in the queue? */
6120 rc = avc_has_perm(msec->sid, isec->sid, SECCLASS_MSGQ,
6121 MSGQ__ENQUEUE, &ad);
6122
6123 return rc;
6124 }
6125
selinux_msg_queue_msgrcv(struct kern_ipc_perm * msq,struct msg_msg * msg,struct task_struct * target,long type,int mode)6126 static int selinux_msg_queue_msgrcv(struct kern_ipc_perm *msq, struct msg_msg *msg,
6127 struct task_struct *target,
6128 long type, int mode)
6129 {
6130 struct ipc_security_struct *isec;
6131 struct msg_security_struct *msec;
6132 struct common_audit_data ad;
6133 u32 sid = task_sid_obj(target);
6134 int rc;
6135
6136 isec = selinux_ipc(msq);
6137 msec = selinux_msg_msg(msg);
6138
6139 ad.type = LSM_AUDIT_DATA_IPC;
6140 ad.u.ipc_id = msq->key;
6141
6142 rc = avc_has_perm(sid, isec->sid,
6143 SECCLASS_MSGQ, MSGQ__READ, &ad);
6144 if (!rc)
6145 rc = avc_has_perm(sid, msec->sid,
6146 SECCLASS_MSG, MSG__RECEIVE, &ad);
6147 return rc;
6148 }
6149
6150 /* Shared Memory security operations */
selinux_shm_alloc_security(struct kern_ipc_perm * shp)6151 static int selinux_shm_alloc_security(struct kern_ipc_perm *shp)
6152 {
6153 struct ipc_security_struct *isec;
6154 struct common_audit_data ad;
6155 u32 sid = current_sid();
6156
6157 isec = selinux_ipc(shp);
6158 ipc_init_security(isec, SECCLASS_SHM);
6159
6160 ad.type = LSM_AUDIT_DATA_IPC;
6161 ad.u.ipc_id = shp->key;
6162
6163 return avc_has_perm(sid, isec->sid, SECCLASS_SHM,
6164 SHM__CREATE, &ad);
6165 }
6166
selinux_shm_associate(struct kern_ipc_perm * shp,int shmflg)6167 static int selinux_shm_associate(struct kern_ipc_perm *shp, int shmflg)
6168 {
6169 struct ipc_security_struct *isec;
6170 struct common_audit_data ad;
6171 u32 sid = current_sid();
6172
6173 isec = selinux_ipc(shp);
6174
6175 ad.type = LSM_AUDIT_DATA_IPC;
6176 ad.u.ipc_id = shp->key;
6177
6178 return avc_has_perm(sid, isec->sid, SECCLASS_SHM,
6179 SHM__ASSOCIATE, &ad);
6180 }
6181
6182 /* Note, at this point, shp is locked down */
selinux_shm_shmctl(struct kern_ipc_perm * shp,int cmd)6183 static int selinux_shm_shmctl(struct kern_ipc_perm *shp, int cmd)
6184 {
6185 u32 perms;
6186
6187 switch (cmd) {
6188 case IPC_INFO:
6189 case SHM_INFO:
6190 /* No specific object, just general system-wide information. */
6191 return avc_has_perm(current_sid(), SECINITSID_KERNEL,
6192 SECCLASS_SYSTEM, SYSTEM__IPC_INFO, NULL);
6193 case IPC_STAT:
6194 case SHM_STAT:
6195 case SHM_STAT_ANY:
6196 perms = SHM__GETATTR | SHM__ASSOCIATE;
6197 break;
6198 case IPC_SET:
6199 perms = SHM__SETATTR;
6200 break;
6201 case SHM_LOCK:
6202 case SHM_UNLOCK:
6203 perms = SHM__LOCK;
6204 break;
6205 case IPC_RMID:
6206 perms = SHM__DESTROY;
6207 break;
6208 default:
6209 return 0;
6210 }
6211
6212 return ipc_has_perm(shp, perms);
6213 }
6214
selinux_shm_shmat(struct kern_ipc_perm * shp,char __user * shmaddr,int shmflg)6215 static int selinux_shm_shmat(struct kern_ipc_perm *shp,
6216 char __user *shmaddr, int shmflg)
6217 {
6218 u32 perms;
6219
6220 if (shmflg & SHM_RDONLY)
6221 perms = SHM__READ;
6222 else
6223 perms = SHM__READ | SHM__WRITE;
6224
6225 return ipc_has_perm(shp, perms);
6226 }
6227
6228 /* Semaphore security operations */
selinux_sem_alloc_security(struct kern_ipc_perm * sma)6229 static int selinux_sem_alloc_security(struct kern_ipc_perm *sma)
6230 {
6231 struct ipc_security_struct *isec;
6232 struct common_audit_data ad;
6233 u32 sid = current_sid();
6234
6235 isec = selinux_ipc(sma);
6236 ipc_init_security(isec, SECCLASS_SEM);
6237
6238 ad.type = LSM_AUDIT_DATA_IPC;
6239 ad.u.ipc_id = sma->key;
6240
6241 return avc_has_perm(sid, isec->sid, SECCLASS_SEM,
6242 SEM__CREATE, &ad);
6243 }
6244
selinux_sem_associate(struct kern_ipc_perm * sma,int semflg)6245 static int selinux_sem_associate(struct kern_ipc_perm *sma, int semflg)
6246 {
6247 struct ipc_security_struct *isec;
6248 struct common_audit_data ad;
6249 u32 sid = current_sid();
6250
6251 isec = selinux_ipc(sma);
6252
6253 ad.type = LSM_AUDIT_DATA_IPC;
6254 ad.u.ipc_id = sma->key;
6255
6256 return avc_has_perm(sid, isec->sid, SECCLASS_SEM,
6257 SEM__ASSOCIATE, &ad);
6258 }
6259
6260 /* Note, at this point, sma is locked down */
selinux_sem_semctl(struct kern_ipc_perm * sma,int cmd)6261 static int selinux_sem_semctl(struct kern_ipc_perm *sma, int cmd)
6262 {
6263 int err;
6264 u32 perms;
6265
6266 switch (cmd) {
6267 case IPC_INFO:
6268 case SEM_INFO:
6269 /* No specific object, just general system-wide information. */
6270 return avc_has_perm(current_sid(), SECINITSID_KERNEL,
6271 SECCLASS_SYSTEM, SYSTEM__IPC_INFO, NULL);
6272 case GETPID:
6273 case GETNCNT:
6274 case GETZCNT:
6275 perms = SEM__GETATTR;
6276 break;
6277 case GETVAL:
6278 case GETALL:
6279 perms = SEM__READ;
6280 break;
6281 case SETVAL:
6282 case SETALL:
6283 perms = SEM__WRITE;
6284 break;
6285 case IPC_RMID:
6286 perms = SEM__DESTROY;
6287 break;
6288 case IPC_SET:
6289 perms = SEM__SETATTR;
6290 break;
6291 case IPC_STAT:
6292 case SEM_STAT:
6293 case SEM_STAT_ANY:
6294 perms = SEM__GETATTR | SEM__ASSOCIATE;
6295 break;
6296 default:
6297 return 0;
6298 }
6299
6300 err = ipc_has_perm(sma, perms);
6301 return err;
6302 }
6303
selinux_sem_semop(struct kern_ipc_perm * sma,struct sembuf * sops,unsigned nsops,int alter)6304 static int selinux_sem_semop(struct kern_ipc_perm *sma,
6305 struct sembuf *sops, unsigned nsops, int alter)
6306 {
6307 u32 perms;
6308
6309 if (alter)
6310 perms = SEM__READ | SEM__WRITE;
6311 else
6312 perms = SEM__READ;
6313
6314 return ipc_has_perm(sma, perms);
6315 }
6316
selinux_ipc_permission(struct kern_ipc_perm * ipcp,short flag)6317 static int selinux_ipc_permission(struct kern_ipc_perm *ipcp, short flag)
6318 {
6319 u32 av = 0;
6320
6321 av = 0;
6322 if (flag & S_IRUGO)
6323 av |= IPC__UNIX_READ;
6324 if (flag & S_IWUGO)
6325 av |= IPC__UNIX_WRITE;
6326
6327 if (av == 0)
6328 return 0;
6329
6330 return ipc_has_perm(ipcp, av);
6331 }
6332
selinux_ipc_getsecid(struct kern_ipc_perm * ipcp,u32 * secid)6333 static void selinux_ipc_getsecid(struct kern_ipc_perm *ipcp, u32 *secid)
6334 {
6335 struct ipc_security_struct *isec = selinux_ipc(ipcp);
6336 *secid = isec->sid;
6337 }
6338
selinux_d_instantiate(struct dentry * dentry,struct inode * inode)6339 static void selinux_d_instantiate(struct dentry *dentry, struct inode *inode)
6340 {
6341 if (inode)
6342 inode_doinit_with_dentry(inode, dentry);
6343 }
6344
selinux_lsm_getattr(unsigned int attr,struct task_struct * p,char ** value)6345 static int selinux_lsm_getattr(unsigned int attr, struct task_struct *p,
6346 char **value)
6347 {
6348 const struct task_security_struct *__tsec;
6349 u32 sid;
6350 int error;
6351 unsigned len;
6352
6353 rcu_read_lock();
6354 __tsec = selinux_cred(__task_cred(p));
6355
6356 if (current != p) {
6357 error = avc_has_perm(current_sid(), __tsec->sid,
6358 SECCLASS_PROCESS, PROCESS__GETATTR, NULL);
6359 if (error)
6360 goto bad;
6361 }
6362
6363 switch (attr) {
6364 case LSM_ATTR_CURRENT:
6365 sid = __tsec->sid;
6366 break;
6367 case LSM_ATTR_PREV:
6368 sid = __tsec->osid;
6369 break;
6370 case LSM_ATTR_EXEC:
6371 sid = __tsec->exec_sid;
6372 break;
6373 case LSM_ATTR_FSCREATE:
6374 sid = __tsec->create_sid;
6375 break;
6376 case LSM_ATTR_KEYCREATE:
6377 sid = __tsec->keycreate_sid;
6378 break;
6379 case LSM_ATTR_SOCKCREATE:
6380 sid = __tsec->sockcreate_sid;
6381 break;
6382 default:
6383 error = -EOPNOTSUPP;
6384 goto bad;
6385 }
6386 rcu_read_unlock();
6387
6388 if (!sid)
6389 return 0;
6390
6391 error = security_sid_to_context(sid, value, &len);
6392 if (error)
6393 return error;
6394 return len;
6395
6396 bad:
6397 rcu_read_unlock();
6398 return error;
6399 }
6400
selinux_lsm_setattr(u64 attr,void * value,size_t size)6401 static int selinux_lsm_setattr(u64 attr, void *value, size_t size)
6402 {
6403 struct task_security_struct *tsec;
6404 struct cred *new;
6405 u32 mysid = current_sid(), sid = 0, ptsid;
6406 int error;
6407 char *str = value;
6408
6409 /*
6410 * Basic control over ability to set these attributes at all.
6411 */
6412 switch (attr) {
6413 case LSM_ATTR_EXEC:
6414 error = avc_has_perm(mysid, mysid, SECCLASS_PROCESS,
6415 PROCESS__SETEXEC, NULL);
6416 break;
6417 case LSM_ATTR_FSCREATE:
6418 error = avc_has_perm(mysid, mysid, SECCLASS_PROCESS,
6419 PROCESS__SETFSCREATE, NULL);
6420 break;
6421 case LSM_ATTR_KEYCREATE:
6422 error = avc_has_perm(mysid, mysid, SECCLASS_PROCESS,
6423 PROCESS__SETKEYCREATE, NULL);
6424 break;
6425 case LSM_ATTR_SOCKCREATE:
6426 error = avc_has_perm(mysid, mysid, SECCLASS_PROCESS,
6427 PROCESS__SETSOCKCREATE, NULL);
6428 break;
6429 case LSM_ATTR_CURRENT:
6430 error = avc_has_perm(mysid, mysid, SECCLASS_PROCESS,
6431 PROCESS__SETCURRENT, NULL);
6432 break;
6433 default:
6434 error = -EOPNOTSUPP;
6435 break;
6436 }
6437 if (error)
6438 return error;
6439
6440 /* Obtain a SID for the context, if one was specified. */
6441 if (size && str[0] && str[0] != '\n') {
6442 if (str[size-1] == '\n') {
6443 str[size-1] = 0;
6444 size--;
6445 }
6446 error = security_context_to_sid(value, size,
6447 &sid, GFP_KERNEL);
6448 if (error == -EINVAL && attr == LSM_ATTR_FSCREATE) {
6449 if (!has_cap_mac_admin(true)) {
6450 struct audit_buffer *ab;
6451 size_t audit_size;
6452
6453 /* We strip a nul only if it is at the end,
6454 * otherwise the context contains a nul and
6455 * we should audit that */
6456 if (str[size - 1] == '\0')
6457 audit_size = size - 1;
6458 else
6459 audit_size = size;
6460 ab = audit_log_start(audit_context(),
6461 GFP_ATOMIC,
6462 AUDIT_SELINUX_ERR);
6463 if (!ab)
6464 return error;
6465 audit_log_format(ab, "op=fscreate invalid_context=");
6466 audit_log_n_untrustedstring(ab, value,
6467 audit_size);
6468 audit_log_end(ab);
6469
6470 return error;
6471 }
6472 error = security_context_to_sid_force(value, size,
6473 &sid);
6474 }
6475 if (error)
6476 return error;
6477 }
6478
6479 new = prepare_creds();
6480 if (!new)
6481 return -ENOMEM;
6482
6483 /* Permission checking based on the specified context is
6484 performed during the actual operation (execve,
6485 open/mkdir/...), when we know the full context of the
6486 operation. See selinux_bprm_creds_for_exec for the execve
6487 checks and may_create for the file creation checks. The
6488 operation will then fail if the context is not permitted. */
6489 tsec = selinux_cred(new);
6490 if (attr == LSM_ATTR_EXEC) {
6491 tsec->exec_sid = sid;
6492 } else if (attr == LSM_ATTR_FSCREATE) {
6493 tsec->create_sid = sid;
6494 } else if (attr == LSM_ATTR_KEYCREATE) {
6495 if (sid) {
6496 error = avc_has_perm(mysid, sid,
6497 SECCLASS_KEY, KEY__CREATE, NULL);
6498 if (error)
6499 goto abort_change;
6500 }
6501 tsec->keycreate_sid = sid;
6502 } else if (attr == LSM_ATTR_SOCKCREATE) {
6503 tsec->sockcreate_sid = sid;
6504 } else if (attr == LSM_ATTR_CURRENT) {
6505 error = -EINVAL;
6506 if (sid == 0)
6507 goto abort_change;
6508
6509 if (!current_is_single_threaded()) {
6510 error = security_bounded_transition(tsec->sid, sid);
6511 if (error)
6512 goto abort_change;
6513 }
6514
6515 /* Check permissions for the transition. */
6516 error = avc_has_perm(tsec->sid, sid, SECCLASS_PROCESS,
6517 PROCESS__DYNTRANSITION, NULL);
6518 if (error)
6519 goto abort_change;
6520
6521 /* Check for ptracing, and update the task SID if ok.
6522 Otherwise, leave SID unchanged and fail. */
6523 ptsid = ptrace_parent_sid();
6524 if (ptsid != 0) {
6525 error = avc_has_perm(ptsid, sid, SECCLASS_PROCESS,
6526 PROCESS__PTRACE, NULL);
6527 if (error)
6528 goto abort_change;
6529 }
6530
6531 tsec->sid = sid;
6532 } else {
6533 error = -EINVAL;
6534 goto abort_change;
6535 }
6536
6537 commit_creds(new);
6538 return size;
6539
6540 abort_change:
6541 abort_creds(new);
6542 return error;
6543 }
6544
6545 /**
6546 * selinux_getselfattr - Get SELinux current task attributes
6547 * @attr: the requested attribute
6548 * @ctx: buffer to receive the result
6549 * @size: buffer size (input), buffer size used (output)
6550 * @flags: unused
6551 *
6552 * Fill the passed user space @ctx with the details of the requested
6553 * attribute.
6554 *
6555 * Returns the number of attributes on success, an error code otherwise.
6556 * There will only ever be one attribute.
6557 */
selinux_getselfattr(unsigned int attr,struct lsm_ctx __user * ctx,size_t * size,u32 flags)6558 static int selinux_getselfattr(unsigned int attr, struct lsm_ctx __user *ctx,
6559 size_t *size, u32 flags)
6560 {
6561 int rc;
6562 char *val = NULL;
6563 int val_len;
6564
6565 val_len = selinux_lsm_getattr(attr, current, &val);
6566 if (val_len < 0)
6567 return val_len;
6568 rc = lsm_fill_user_ctx(ctx, size, val, val_len, LSM_ID_SELINUX, 0);
6569 kfree(val);
6570 return (!rc ? 1 : rc);
6571 }
6572
selinux_setselfattr(unsigned int attr,struct lsm_ctx * ctx,size_t size,u32 flags)6573 static int selinux_setselfattr(unsigned int attr, struct lsm_ctx *ctx,
6574 size_t size, u32 flags)
6575 {
6576 int rc;
6577
6578 rc = selinux_lsm_setattr(attr, ctx->ctx, ctx->ctx_len);
6579 if (rc > 0)
6580 return 0;
6581 return rc;
6582 }
6583
selinux_getprocattr(struct task_struct * p,const char * name,char ** value)6584 static int selinux_getprocattr(struct task_struct *p,
6585 const char *name, char **value)
6586 {
6587 unsigned int attr = lsm_name_to_attr(name);
6588 int rc;
6589
6590 if (attr) {
6591 rc = selinux_lsm_getattr(attr, p, value);
6592 if (rc != -EOPNOTSUPP)
6593 return rc;
6594 }
6595
6596 return -EINVAL;
6597 }
6598
selinux_setprocattr(const char * name,void * value,size_t size)6599 static int selinux_setprocattr(const char *name, void *value, size_t size)
6600 {
6601 int attr = lsm_name_to_attr(name);
6602
6603 if (attr)
6604 return selinux_lsm_setattr(attr, value, size);
6605 return -EINVAL;
6606 }
6607
selinux_ismaclabel(const char * name)6608 static int selinux_ismaclabel(const char *name)
6609 {
6610 return (strcmp(name, XATTR_SELINUX_SUFFIX) == 0);
6611 }
6612
selinux_secid_to_secctx(u32 secid,char ** secdata,u32 * seclen)6613 static int selinux_secid_to_secctx(u32 secid, char **secdata, u32 *seclen)
6614 {
6615 return security_sid_to_context(secid,
6616 secdata, seclen);
6617 }
6618
selinux_secctx_to_secid(const char * secdata,u32 seclen,u32 * secid)6619 static int selinux_secctx_to_secid(const char *secdata, u32 seclen, u32 *secid)
6620 {
6621 return security_context_to_sid(secdata, seclen,
6622 secid, GFP_KERNEL);
6623 }
6624
selinux_release_secctx(char * secdata,u32 seclen)6625 static void selinux_release_secctx(char *secdata, u32 seclen)
6626 {
6627 kfree(secdata);
6628 }
6629
selinux_inode_invalidate_secctx(struct inode * inode)6630 static void selinux_inode_invalidate_secctx(struct inode *inode)
6631 {
6632 struct inode_security_struct *isec = selinux_inode(inode);
6633
6634 spin_lock(&isec->lock);
6635 isec->initialized = LABEL_INVALID;
6636 spin_unlock(&isec->lock);
6637 }
6638
6639 /*
6640 * called with inode->i_mutex locked
6641 */
selinux_inode_notifysecctx(struct inode * inode,void * ctx,u32 ctxlen)6642 static int selinux_inode_notifysecctx(struct inode *inode, void *ctx, u32 ctxlen)
6643 {
6644 int rc = selinux_inode_setsecurity(inode, XATTR_SELINUX_SUFFIX,
6645 ctx, ctxlen, 0);
6646 /* Do not return error when suppressing label (SBLABEL_MNT not set). */
6647 return rc == -EOPNOTSUPP ? 0 : rc;
6648 }
6649
6650 /*
6651 * called with inode->i_mutex locked
6652 */
selinux_inode_setsecctx(struct dentry * dentry,void * ctx,u32 ctxlen)6653 static int selinux_inode_setsecctx(struct dentry *dentry, void *ctx, u32 ctxlen)
6654 {
6655 return __vfs_setxattr_noperm(&nop_mnt_idmap, dentry, XATTR_NAME_SELINUX,
6656 ctx, ctxlen, 0);
6657 }
6658
selinux_inode_getsecctx(struct inode * inode,void ** ctx,u32 * ctxlen)6659 static int selinux_inode_getsecctx(struct inode *inode, void **ctx, u32 *ctxlen)
6660 {
6661 int len = 0;
6662 len = selinux_inode_getsecurity(&nop_mnt_idmap, inode,
6663 XATTR_SELINUX_SUFFIX, ctx, true);
6664 if (len < 0)
6665 return len;
6666 *ctxlen = len;
6667 return 0;
6668 }
6669 #ifdef CONFIG_KEYS
6670
selinux_key_alloc(struct key * k,const struct cred * cred,unsigned long flags)6671 static int selinux_key_alloc(struct key *k, const struct cred *cred,
6672 unsigned long flags)
6673 {
6674 const struct task_security_struct *tsec;
6675 struct key_security_struct *ksec;
6676
6677 ksec = kzalloc(sizeof(struct key_security_struct), GFP_KERNEL);
6678 if (!ksec)
6679 return -ENOMEM;
6680
6681 tsec = selinux_cred(cred);
6682 if (tsec->keycreate_sid)
6683 ksec->sid = tsec->keycreate_sid;
6684 else
6685 ksec->sid = tsec->sid;
6686
6687 k->security = ksec;
6688 return 0;
6689 }
6690
selinux_key_free(struct key * k)6691 static void selinux_key_free(struct key *k)
6692 {
6693 struct key_security_struct *ksec = k->security;
6694
6695 k->security = NULL;
6696 kfree(ksec);
6697 }
6698
selinux_key_permission(key_ref_t key_ref,const struct cred * cred,enum key_need_perm need_perm)6699 static int selinux_key_permission(key_ref_t key_ref,
6700 const struct cred *cred,
6701 enum key_need_perm need_perm)
6702 {
6703 struct key *key;
6704 struct key_security_struct *ksec;
6705 u32 perm, sid;
6706
6707 switch (need_perm) {
6708 case KEY_NEED_VIEW:
6709 perm = KEY__VIEW;
6710 break;
6711 case KEY_NEED_READ:
6712 perm = KEY__READ;
6713 break;
6714 case KEY_NEED_WRITE:
6715 perm = KEY__WRITE;
6716 break;
6717 case KEY_NEED_SEARCH:
6718 perm = KEY__SEARCH;
6719 break;
6720 case KEY_NEED_LINK:
6721 perm = KEY__LINK;
6722 break;
6723 case KEY_NEED_SETATTR:
6724 perm = KEY__SETATTR;
6725 break;
6726 case KEY_NEED_UNLINK:
6727 case KEY_SYSADMIN_OVERRIDE:
6728 case KEY_AUTHTOKEN_OVERRIDE:
6729 case KEY_DEFER_PERM_CHECK:
6730 return 0;
6731 default:
6732 WARN_ON(1);
6733 return -EPERM;
6734
6735 }
6736
6737 sid = cred_sid(cred);
6738 key = key_ref_to_ptr(key_ref);
6739 ksec = key->security;
6740
6741 return avc_has_perm(sid, ksec->sid, SECCLASS_KEY, perm, NULL);
6742 }
6743
selinux_key_getsecurity(struct key * key,char ** _buffer)6744 static int selinux_key_getsecurity(struct key *key, char **_buffer)
6745 {
6746 struct key_security_struct *ksec = key->security;
6747 char *context = NULL;
6748 unsigned len;
6749 int rc;
6750
6751 rc = security_sid_to_context(ksec->sid,
6752 &context, &len);
6753 if (!rc)
6754 rc = len;
6755 *_buffer = context;
6756 return rc;
6757 }
6758
6759 #ifdef CONFIG_KEY_NOTIFICATIONS
selinux_watch_key(struct key * key)6760 static int selinux_watch_key(struct key *key)
6761 {
6762 struct key_security_struct *ksec = key->security;
6763 u32 sid = current_sid();
6764
6765 return avc_has_perm(sid, ksec->sid, SECCLASS_KEY, KEY__VIEW, NULL);
6766 }
6767 #endif
6768 #endif
6769
6770 #ifdef CONFIG_SECURITY_INFINIBAND
selinux_ib_pkey_access(void * ib_sec,u64 subnet_prefix,u16 pkey_val)6771 static int selinux_ib_pkey_access(void *ib_sec, u64 subnet_prefix, u16 pkey_val)
6772 {
6773 struct common_audit_data ad;
6774 int err;
6775 u32 sid = 0;
6776 struct ib_security_struct *sec = ib_sec;
6777 struct lsm_ibpkey_audit ibpkey;
6778
6779 err = sel_ib_pkey_sid(subnet_prefix, pkey_val, &sid);
6780 if (err)
6781 return err;
6782
6783 ad.type = LSM_AUDIT_DATA_IBPKEY;
6784 ibpkey.subnet_prefix = subnet_prefix;
6785 ibpkey.pkey = pkey_val;
6786 ad.u.ibpkey = &ibpkey;
6787 return avc_has_perm(sec->sid, sid,
6788 SECCLASS_INFINIBAND_PKEY,
6789 INFINIBAND_PKEY__ACCESS, &ad);
6790 }
6791
selinux_ib_endport_manage_subnet(void * ib_sec,const char * dev_name,u8 port_num)6792 static int selinux_ib_endport_manage_subnet(void *ib_sec, const char *dev_name,
6793 u8 port_num)
6794 {
6795 struct common_audit_data ad;
6796 int err;
6797 u32 sid = 0;
6798 struct ib_security_struct *sec = ib_sec;
6799 struct lsm_ibendport_audit ibendport;
6800
6801 err = security_ib_endport_sid(dev_name, port_num,
6802 &sid);
6803
6804 if (err)
6805 return err;
6806
6807 ad.type = LSM_AUDIT_DATA_IBENDPORT;
6808 ibendport.dev_name = dev_name;
6809 ibendport.port = port_num;
6810 ad.u.ibendport = &ibendport;
6811 return avc_has_perm(sec->sid, sid,
6812 SECCLASS_INFINIBAND_ENDPORT,
6813 INFINIBAND_ENDPORT__MANAGE_SUBNET, &ad);
6814 }
6815
selinux_ib_alloc_security(void ** ib_sec)6816 static int selinux_ib_alloc_security(void **ib_sec)
6817 {
6818 struct ib_security_struct *sec;
6819
6820 sec = kzalloc(sizeof(*sec), GFP_KERNEL);
6821 if (!sec)
6822 return -ENOMEM;
6823 sec->sid = current_sid();
6824
6825 *ib_sec = sec;
6826 return 0;
6827 }
6828
selinux_ib_free_security(void * ib_sec)6829 static void selinux_ib_free_security(void *ib_sec)
6830 {
6831 kfree(ib_sec);
6832 }
6833 #endif
6834
6835 #ifdef CONFIG_BPF_SYSCALL
selinux_bpf(int cmd,union bpf_attr * attr,unsigned int size)6836 static int selinux_bpf(int cmd, union bpf_attr *attr,
6837 unsigned int size)
6838 {
6839 u32 sid = current_sid();
6840 int ret;
6841
6842 switch (cmd) {
6843 case BPF_MAP_CREATE:
6844 ret = avc_has_perm(sid, sid, SECCLASS_BPF, BPF__MAP_CREATE,
6845 NULL);
6846 break;
6847 case BPF_PROG_LOAD:
6848 ret = avc_has_perm(sid, sid, SECCLASS_BPF, BPF__PROG_LOAD,
6849 NULL);
6850 break;
6851 default:
6852 ret = 0;
6853 break;
6854 }
6855
6856 return ret;
6857 }
6858
bpf_map_fmode_to_av(fmode_t fmode)6859 static u32 bpf_map_fmode_to_av(fmode_t fmode)
6860 {
6861 u32 av = 0;
6862
6863 if (fmode & FMODE_READ)
6864 av |= BPF__MAP_READ;
6865 if (fmode & FMODE_WRITE)
6866 av |= BPF__MAP_WRITE;
6867 return av;
6868 }
6869
6870 /* This function will check the file pass through unix socket or binder to see
6871 * if it is a bpf related object. And apply corresponding checks on the bpf
6872 * object based on the type. The bpf maps and programs, not like other files and
6873 * socket, are using a shared anonymous inode inside the kernel as their inode.
6874 * So checking that inode cannot identify if the process have privilege to
6875 * access the bpf object and that's why we have to add this additional check in
6876 * selinux_file_receive and selinux_binder_transfer_files.
6877 */
bpf_fd_pass(const struct file * file,u32 sid)6878 static int bpf_fd_pass(const struct file *file, u32 sid)
6879 {
6880 struct bpf_security_struct *bpfsec;
6881 struct bpf_prog *prog;
6882 struct bpf_map *map;
6883 int ret;
6884
6885 if (file->f_op == &bpf_map_fops) {
6886 map = file->private_data;
6887 bpfsec = map->security;
6888 ret = avc_has_perm(sid, bpfsec->sid, SECCLASS_BPF,
6889 bpf_map_fmode_to_av(file->f_mode), NULL);
6890 if (ret)
6891 return ret;
6892 } else if (file->f_op == &bpf_prog_fops) {
6893 prog = file->private_data;
6894 bpfsec = prog->aux->security;
6895 ret = avc_has_perm(sid, bpfsec->sid, SECCLASS_BPF,
6896 BPF__PROG_RUN, NULL);
6897 if (ret)
6898 return ret;
6899 }
6900 return 0;
6901 }
6902
selinux_bpf_map(struct bpf_map * map,fmode_t fmode)6903 static int selinux_bpf_map(struct bpf_map *map, fmode_t fmode)
6904 {
6905 u32 sid = current_sid();
6906 struct bpf_security_struct *bpfsec;
6907
6908 bpfsec = map->security;
6909 return avc_has_perm(sid, bpfsec->sid, SECCLASS_BPF,
6910 bpf_map_fmode_to_av(fmode), NULL);
6911 }
6912
selinux_bpf_prog(struct bpf_prog * prog)6913 static int selinux_bpf_prog(struct bpf_prog *prog)
6914 {
6915 u32 sid = current_sid();
6916 struct bpf_security_struct *bpfsec;
6917
6918 bpfsec = prog->aux->security;
6919 return avc_has_perm(sid, bpfsec->sid, SECCLASS_BPF,
6920 BPF__PROG_RUN, NULL);
6921 }
6922
selinux_bpf_map_alloc(struct bpf_map * map)6923 static int selinux_bpf_map_alloc(struct bpf_map *map)
6924 {
6925 struct bpf_security_struct *bpfsec;
6926
6927 bpfsec = kzalloc(sizeof(*bpfsec), GFP_KERNEL);
6928 if (!bpfsec)
6929 return -ENOMEM;
6930
6931 bpfsec->sid = current_sid();
6932 map->security = bpfsec;
6933
6934 return 0;
6935 }
6936
selinux_bpf_map_free(struct bpf_map * map)6937 static void selinux_bpf_map_free(struct bpf_map *map)
6938 {
6939 struct bpf_security_struct *bpfsec = map->security;
6940
6941 map->security = NULL;
6942 kfree(bpfsec);
6943 }
6944
selinux_bpf_prog_alloc(struct bpf_prog_aux * aux)6945 static int selinux_bpf_prog_alloc(struct bpf_prog_aux *aux)
6946 {
6947 struct bpf_security_struct *bpfsec;
6948
6949 bpfsec = kzalloc(sizeof(*bpfsec), GFP_KERNEL);
6950 if (!bpfsec)
6951 return -ENOMEM;
6952
6953 bpfsec->sid = current_sid();
6954 aux->security = bpfsec;
6955
6956 return 0;
6957 }
6958
selinux_bpf_prog_free(struct bpf_prog_aux * aux)6959 static void selinux_bpf_prog_free(struct bpf_prog_aux *aux)
6960 {
6961 struct bpf_security_struct *bpfsec = aux->security;
6962
6963 aux->security = NULL;
6964 kfree(bpfsec);
6965 }
6966 #endif
6967
6968 struct lsm_blob_sizes selinux_blob_sizes __ro_after_init = {
6969 .lbs_cred = sizeof(struct task_security_struct),
6970 .lbs_file = sizeof(struct file_security_struct),
6971 .lbs_inode = sizeof(struct inode_security_struct),
6972 .lbs_ipc = sizeof(struct ipc_security_struct),
6973 .lbs_msg_msg = sizeof(struct msg_security_struct),
6974 .lbs_superblock = sizeof(struct superblock_security_struct),
6975 .lbs_xattr_count = SELINUX_INODE_INIT_XATTRS,
6976 };
6977
6978 #ifdef CONFIG_PERF_EVENTS
selinux_perf_event_open(struct perf_event_attr * attr,int type)6979 static int selinux_perf_event_open(struct perf_event_attr *attr, int type)
6980 {
6981 u32 requested, sid = current_sid();
6982
6983 if (type == PERF_SECURITY_OPEN)
6984 requested = PERF_EVENT__OPEN;
6985 else if (type == PERF_SECURITY_CPU)
6986 requested = PERF_EVENT__CPU;
6987 else if (type == PERF_SECURITY_KERNEL)
6988 requested = PERF_EVENT__KERNEL;
6989 else if (type == PERF_SECURITY_TRACEPOINT)
6990 requested = PERF_EVENT__TRACEPOINT;
6991 else
6992 return -EINVAL;
6993
6994 return avc_has_perm(sid, sid, SECCLASS_PERF_EVENT,
6995 requested, NULL);
6996 }
6997
selinux_perf_event_alloc(struct perf_event * event)6998 static int selinux_perf_event_alloc(struct perf_event *event)
6999 {
7000 struct perf_event_security_struct *perfsec;
7001
7002 perfsec = kzalloc(sizeof(*perfsec), GFP_KERNEL);
7003 if (!perfsec)
7004 return -ENOMEM;
7005
7006 perfsec->sid = current_sid();
7007 event->security = perfsec;
7008
7009 return 0;
7010 }
7011
selinux_perf_event_free(struct perf_event * event)7012 static void selinux_perf_event_free(struct perf_event *event)
7013 {
7014 struct perf_event_security_struct *perfsec = event->security;
7015
7016 event->security = NULL;
7017 kfree(perfsec);
7018 }
7019
selinux_perf_event_read(struct perf_event * event)7020 static int selinux_perf_event_read(struct perf_event *event)
7021 {
7022 struct perf_event_security_struct *perfsec = event->security;
7023 u32 sid = current_sid();
7024
7025 return avc_has_perm(sid, perfsec->sid,
7026 SECCLASS_PERF_EVENT, PERF_EVENT__READ, NULL);
7027 }
7028
selinux_perf_event_write(struct perf_event * event)7029 static int selinux_perf_event_write(struct perf_event *event)
7030 {
7031 struct perf_event_security_struct *perfsec = event->security;
7032 u32 sid = current_sid();
7033
7034 return avc_has_perm(sid, perfsec->sid,
7035 SECCLASS_PERF_EVENT, PERF_EVENT__WRITE, NULL);
7036 }
7037 #endif
7038
7039 #ifdef CONFIG_IO_URING
7040 /**
7041 * selinux_uring_override_creds - check the requested cred override
7042 * @new: the target creds
7043 *
7044 * Check to see if the current task is allowed to override it's credentials
7045 * to service an io_uring operation.
7046 */
selinux_uring_override_creds(const struct cred * new)7047 static int selinux_uring_override_creds(const struct cred *new)
7048 {
7049 return avc_has_perm(current_sid(), cred_sid(new),
7050 SECCLASS_IO_URING, IO_URING__OVERRIDE_CREDS, NULL);
7051 }
7052
7053 /**
7054 * selinux_uring_sqpoll - check if a io_uring polling thread can be created
7055 *
7056 * Check to see if the current task is allowed to create a new io_uring
7057 * kernel polling thread.
7058 */
selinux_uring_sqpoll(void)7059 static int selinux_uring_sqpoll(void)
7060 {
7061 u32 sid = current_sid();
7062
7063 return avc_has_perm(sid, sid,
7064 SECCLASS_IO_URING, IO_URING__SQPOLL, NULL);
7065 }
7066
7067 /**
7068 * selinux_uring_cmd - check if IORING_OP_URING_CMD is allowed
7069 * @ioucmd: the io_uring command structure
7070 *
7071 * Check to see if the current domain is allowed to execute an
7072 * IORING_OP_URING_CMD against the device/file specified in @ioucmd.
7073 *
7074 */
selinux_uring_cmd(struct io_uring_cmd * ioucmd)7075 static int selinux_uring_cmd(struct io_uring_cmd *ioucmd)
7076 {
7077 struct file *file = ioucmd->file;
7078 struct inode *inode = file_inode(file);
7079 struct inode_security_struct *isec = selinux_inode(inode);
7080 struct common_audit_data ad;
7081
7082 ad.type = LSM_AUDIT_DATA_FILE;
7083 ad.u.file = file;
7084
7085 return avc_has_perm(current_sid(), isec->sid,
7086 SECCLASS_IO_URING, IO_URING__CMD, &ad);
7087 }
7088 #endif /* CONFIG_IO_URING */
7089
7090 static const struct lsm_id selinux_lsmid = {
7091 .name = "selinux",
7092 .id = LSM_ID_SELINUX,
7093 };
7094
7095 /*
7096 * IMPORTANT NOTE: When adding new hooks, please be careful to keep this order:
7097 * 1. any hooks that don't belong to (2.) or (3.) below,
7098 * 2. hooks that both access structures allocated by other hooks, and allocate
7099 * structures that can be later accessed by other hooks (mostly "cloning"
7100 * hooks),
7101 * 3. hooks that only allocate structures that can be later accessed by other
7102 * hooks ("allocating" hooks).
7103 *
7104 * Please follow block comment delimiters in the list to keep this order.
7105 */
7106 static struct security_hook_list selinux_hooks[] __ro_after_init = {
7107 LSM_HOOK_INIT(binder_set_context_mgr, selinux_binder_set_context_mgr),
7108 LSM_HOOK_INIT(binder_transaction, selinux_binder_transaction),
7109 LSM_HOOK_INIT(binder_transfer_binder, selinux_binder_transfer_binder),
7110 LSM_HOOK_INIT(binder_transfer_file, selinux_binder_transfer_file),
7111
7112 LSM_HOOK_INIT(ptrace_access_check, selinux_ptrace_access_check),
7113 LSM_HOOK_INIT(ptrace_traceme, selinux_ptrace_traceme),
7114 LSM_HOOK_INIT(capget, selinux_capget),
7115 LSM_HOOK_INIT(capset, selinux_capset),
7116 LSM_HOOK_INIT(capable, selinux_capable),
7117 LSM_HOOK_INIT(quotactl, selinux_quotactl),
7118 LSM_HOOK_INIT(quota_on, selinux_quota_on),
7119 LSM_HOOK_INIT(syslog, selinux_syslog),
7120 LSM_HOOK_INIT(vm_enough_memory, selinux_vm_enough_memory),
7121
7122 LSM_HOOK_INIT(netlink_send, selinux_netlink_send),
7123
7124 LSM_HOOK_INIT(bprm_creds_for_exec, selinux_bprm_creds_for_exec),
7125 LSM_HOOK_INIT(bprm_committing_creds, selinux_bprm_committing_creds),
7126 LSM_HOOK_INIT(bprm_committed_creds, selinux_bprm_committed_creds),
7127
7128 LSM_HOOK_INIT(sb_free_mnt_opts, selinux_free_mnt_opts),
7129 LSM_HOOK_INIT(sb_mnt_opts_compat, selinux_sb_mnt_opts_compat),
7130 LSM_HOOK_INIT(sb_remount, selinux_sb_remount),
7131 LSM_HOOK_INIT(sb_kern_mount, selinux_sb_kern_mount),
7132 LSM_HOOK_INIT(sb_show_options, selinux_sb_show_options),
7133 LSM_HOOK_INIT(sb_statfs, selinux_sb_statfs),
7134 LSM_HOOK_INIT(sb_mount, selinux_mount),
7135 LSM_HOOK_INIT(sb_umount, selinux_umount),
7136 LSM_HOOK_INIT(sb_set_mnt_opts, selinux_set_mnt_opts),
7137 LSM_HOOK_INIT(sb_clone_mnt_opts, selinux_sb_clone_mnt_opts),
7138
7139 LSM_HOOK_INIT(move_mount, selinux_move_mount),
7140
7141 LSM_HOOK_INIT(dentry_init_security, selinux_dentry_init_security),
7142 LSM_HOOK_INIT(dentry_create_files_as, selinux_dentry_create_files_as),
7143
7144 LSM_HOOK_INIT(inode_free_security, selinux_inode_free_security),
7145 LSM_HOOK_INIT(inode_init_security, selinux_inode_init_security),
7146 LSM_HOOK_INIT(inode_init_security_anon, selinux_inode_init_security_anon),
7147 LSM_HOOK_INIT(inode_create, selinux_inode_create),
7148 LSM_HOOK_INIT(inode_link, selinux_inode_link),
7149 LSM_HOOK_INIT(inode_unlink, selinux_inode_unlink),
7150 LSM_HOOK_INIT(inode_symlink, selinux_inode_symlink),
7151 LSM_HOOK_INIT(inode_mkdir, selinux_inode_mkdir),
7152 LSM_HOOK_INIT(inode_rmdir, selinux_inode_rmdir),
7153 LSM_HOOK_INIT(inode_mknod, selinux_inode_mknod),
7154 LSM_HOOK_INIT(inode_rename, selinux_inode_rename),
7155 LSM_HOOK_INIT(inode_readlink, selinux_inode_readlink),
7156 LSM_HOOK_INIT(inode_follow_link, selinux_inode_follow_link),
7157 LSM_HOOK_INIT(inode_permission, selinux_inode_permission),
7158 LSM_HOOK_INIT(inode_setattr, selinux_inode_setattr),
7159 LSM_HOOK_INIT(inode_getattr, selinux_inode_getattr),
7160 LSM_HOOK_INIT(inode_setxattr, selinux_inode_setxattr),
7161 LSM_HOOK_INIT(inode_post_setxattr, selinux_inode_post_setxattr),
7162 LSM_HOOK_INIT(inode_getxattr, selinux_inode_getxattr),
7163 LSM_HOOK_INIT(inode_listxattr, selinux_inode_listxattr),
7164 LSM_HOOK_INIT(inode_removexattr, selinux_inode_removexattr),
7165 LSM_HOOK_INIT(inode_set_acl, selinux_inode_set_acl),
7166 LSM_HOOK_INIT(inode_get_acl, selinux_inode_get_acl),
7167 LSM_HOOK_INIT(inode_remove_acl, selinux_inode_remove_acl),
7168 LSM_HOOK_INIT(inode_getsecurity, selinux_inode_getsecurity),
7169 LSM_HOOK_INIT(inode_setsecurity, selinux_inode_setsecurity),
7170 LSM_HOOK_INIT(inode_listsecurity, selinux_inode_listsecurity),
7171 LSM_HOOK_INIT(inode_getsecid, selinux_inode_getsecid),
7172 LSM_HOOK_INIT(inode_copy_up, selinux_inode_copy_up),
7173 LSM_HOOK_INIT(inode_copy_up_xattr, selinux_inode_copy_up_xattr),
7174 LSM_HOOK_INIT(path_notify, selinux_path_notify),
7175
7176 LSM_HOOK_INIT(kernfs_init_security, selinux_kernfs_init_security),
7177
7178 LSM_HOOK_INIT(file_permission, selinux_file_permission),
7179 LSM_HOOK_INIT(file_alloc_security, selinux_file_alloc_security),
7180 LSM_HOOK_INIT(file_ioctl, selinux_file_ioctl),
7181 LSM_HOOK_INIT(file_ioctl_compat, selinux_file_ioctl_compat),
7182 LSM_HOOK_INIT(mmap_file, selinux_mmap_file),
7183 LSM_HOOK_INIT(mmap_addr, selinux_mmap_addr),
7184 LSM_HOOK_INIT(file_mprotect, selinux_file_mprotect),
7185 LSM_HOOK_INIT(file_lock, selinux_file_lock),
7186 LSM_HOOK_INIT(file_fcntl, selinux_file_fcntl),
7187 LSM_HOOK_INIT(file_set_fowner, selinux_file_set_fowner),
7188 LSM_HOOK_INIT(file_send_sigiotask, selinux_file_send_sigiotask),
7189 LSM_HOOK_INIT(file_receive, selinux_file_receive),
7190
7191 LSM_HOOK_INIT(file_open, selinux_file_open),
7192
7193 LSM_HOOK_INIT(task_alloc, selinux_task_alloc),
7194 LSM_HOOK_INIT(cred_prepare, selinux_cred_prepare),
7195 LSM_HOOK_INIT(cred_transfer, selinux_cred_transfer),
7196 LSM_HOOK_INIT(cred_getsecid, selinux_cred_getsecid),
7197 LSM_HOOK_INIT(kernel_act_as, selinux_kernel_act_as),
7198 LSM_HOOK_INIT(kernel_create_files_as, selinux_kernel_create_files_as),
7199 LSM_HOOK_INIT(kernel_module_request, selinux_kernel_module_request),
7200 LSM_HOOK_INIT(kernel_load_data, selinux_kernel_load_data),
7201 LSM_HOOK_INIT(kernel_read_file, selinux_kernel_read_file),
7202 LSM_HOOK_INIT(task_setpgid, selinux_task_setpgid),
7203 LSM_HOOK_INIT(task_getpgid, selinux_task_getpgid),
7204 LSM_HOOK_INIT(task_getsid, selinux_task_getsid),
7205 LSM_HOOK_INIT(current_getsecid_subj, selinux_current_getsecid_subj),
7206 LSM_HOOK_INIT(task_getsecid_obj, selinux_task_getsecid_obj),
7207 LSM_HOOK_INIT(task_setnice, selinux_task_setnice),
7208 LSM_HOOK_INIT(task_setioprio, selinux_task_setioprio),
7209 LSM_HOOK_INIT(task_getioprio, selinux_task_getioprio),
7210 LSM_HOOK_INIT(task_prlimit, selinux_task_prlimit),
7211 LSM_HOOK_INIT(task_setrlimit, selinux_task_setrlimit),
7212 LSM_HOOK_INIT(task_setscheduler, selinux_task_setscheduler),
7213 LSM_HOOK_INIT(task_getscheduler, selinux_task_getscheduler),
7214 LSM_HOOK_INIT(task_movememory, selinux_task_movememory),
7215 LSM_HOOK_INIT(task_kill, selinux_task_kill),
7216 LSM_HOOK_INIT(task_to_inode, selinux_task_to_inode),
7217 LSM_HOOK_INIT(userns_create, selinux_userns_create),
7218
7219 LSM_HOOK_INIT(ipc_permission, selinux_ipc_permission),
7220 LSM_HOOK_INIT(ipc_getsecid, selinux_ipc_getsecid),
7221
7222 LSM_HOOK_INIT(msg_queue_associate, selinux_msg_queue_associate),
7223 LSM_HOOK_INIT(msg_queue_msgctl, selinux_msg_queue_msgctl),
7224 LSM_HOOK_INIT(msg_queue_msgsnd, selinux_msg_queue_msgsnd),
7225 LSM_HOOK_INIT(msg_queue_msgrcv, selinux_msg_queue_msgrcv),
7226
7227 LSM_HOOK_INIT(shm_associate, selinux_shm_associate),
7228 LSM_HOOK_INIT(shm_shmctl, selinux_shm_shmctl),
7229 LSM_HOOK_INIT(shm_shmat, selinux_shm_shmat),
7230
7231 LSM_HOOK_INIT(sem_associate, selinux_sem_associate),
7232 LSM_HOOK_INIT(sem_semctl, selinux_sem_semctl),
7233 LSM_HOOK_INIT(sem_semop, selinux_sem_semop),
7234
7235 LSM_HOOK_INIT(d_instantiate, selinux_d_instantiate),
7236
7237 LSM_HOOK_INIT(getselfattr, selinux_getselfattr),
7238 LSM_HOOK_INIT(setselfattr, selinux_setselfattr),
7239 LSM_HOOK_INIT(getprocattr, selinux_getprocattr),
7240 LSM_HOOK_INIT(setprocattr, selinux_setprocattr),
7241
7242 LSM_HOOK_INIT(ismaclabel, selinux_ismaclabel),
7243 LSM_HOOK_INIT(secctx_to_secid, selinux_secctx_to_secid),
7244 LSM_HOOK_INIT(release_secctx, selinux_release_secctx),
7245 LSM_HOOK_INIT(inode_invalidate_secctx, selinux_inode_invalidate_secctx),
7246 LSM_HOOK_INIT(inode_notifysecctx, selinux_inode_notifysecctx),
7247 LSM_HOOK_INIT(inode_setsecctx, selinux_inode_setsecctx),
7248
7249 LSM_HOOK_INIT(unix_stream_connect, selinux_socket_unix_stream_connect),
7250 LSM_HOOK_INIT(unix_may_send, selinux_socket_unix_may_send),
7251
7252 LSM_HOOK_INIT(socket_create, selinux_socket_create),
7253 LSM_HOOK_INIT(socket_post_create, selinux_socket_post_create),
7254 LSM_HOOK_INIT(socket_socketpair, selinux_socket_socketpair),
7255 LSM_HOOK_INIT(socket_bind, selinux_socket_bind),
7256 LSM_HOOK_INIT(socket_connect, selinux_socket_connect),
7257 LSM_HOOK_INIT(socket_listen, selinux_socket_listen),
7258 LSM_HOOK_INIT(socket_accept, selinux_socket_accept),
7259 LSM_HOOK_INIT(socket_sendmsg, selinux_socket_sendmsg),
7260 LSM_HOOK_INIT(socket_recvmsg, selinux_socket_recvmsg),
7261 LSM_HOOK_INIT(socket_getsockname, selinux_socket_getsockname),
7262 LSM_HOOK_INIT(socket_getpeername, selinux_socket_getpeername),
7263 LSM_HOOK_INIT(socket_getsockopt, selinux_socket_getsockopt),
7264 LSM_HOOK_INIT(socket_setsockopt, selinux_socket_setsockopt),
7265 LSM_HOOK_INIT(socket_shutdown, selinux_socket_shutdown),
7266 LSM_HOOK_INIT(socket_sock_rcv_skb, selinux_socket_sock_rcv_skb),
7267 LSM_HOOK_INIT(socket_getpeersec_stream,
7268 selinux_socket_getpeersec_stream),
7269 LSM_HOOK_INIT(socket_getpeersec_dgram, selinux_socket_getpeersec_dgram),
7270 LSM_HOOK_INIT(sk_free_security, selinux_sk_free_security),
7271 LSM_HOOK_INIT(sk_clone_security, selinux_sk_clone_security),
7272 LSM_HOOK_INIT(sk_getsecid, selinux_sk_getsecid),
7273 LSM_HOOK_INIT(sock_graft, selinux_sock_graft),
7274 LSM_HOOK_INIT(sctp_assoc_request, selinux_sctp_assoc_request),
7275 LSM_HOOK_INIT(sctp_sk_clone, selinux_sctp_sk_clone),
7276 LSM_HOOK_INIT(sctp_bind_connect, selinux_sctp_bind_connect),
7277 LSM_HOOK_INIT(sctp_assoc_established, selinux_sctp_assoc_established),
7278 LSM_HOOK_INIT(mptcp_add_subflow, selinux_mptcp_add_subflow),
7279 LSM_HOOK_INIT(inet_conn_request, selinux_inet_conn_request),
7280 LSM_HOOK_INIT(inet_csk_clone, selinux_inet_csk_clone),
7281 LSM_HOOK_INIT(inet_conn_established, selinux_inet_conn_established),
7282 LSM_HOOK_INIT(secmark_relabel_packet, selinux_secmark_relabel_packet),
7283 LSM_HOOK_INIT(secmark_refcount_inc, selinux_secmark_refcount_inc),
7284 LSM_HOOK_INIT(secmark_refcount_dec, selinux_secmark_refcount_dec),
7285 LSM_HOOK_INIT(req_classify_flow, selinux_req_classify_flow),
7286 LSM_HOOK_INIT(tun_dev_free_security, selinux_tun_dev_free_security),
7287 LSM_HOOK_INIT(tun_dev_create, selinux_tun_dev_create),
7288 LSM_HOOK_INIT(tun_dev_attach_queue, selinux_tun_dev_attach_queue),
7289 LSM_HOOK_INIT(tun_dev_attach, selinux_tun_dev_attach),
7290 LSM_HOOK_INIT(tun_dev_open, selinux_tun_dev_open),
7291 #ifdef CONFIG_SECURITY_INFINIBAND
7292 LSM_HOOK_INIT(ib_pkey_access, selinux_ib_pkey_access),
7293 LSM_HOOK_INIT(ib_endport_manage_subnet,
7294 selinux_ib_endport_manage_subnet),
7295 LSM_HOOK_INIT(ib_free_security, selinux_ib_free_security),
7296 #endif
7297 #ifdef CONFIG_SECURITY_NETWORK_XFRM
7298 LSM_HOOK_INIT(xfrm_policy_free_security, selinux_xfrm_policy_free),
7299 LSM_HOOK_INIT(xfrm_policy_delete_security, selinux_xfrm_policy_delete),
7300 LSM_HOOK_INIT(xfrm_state_free_security, selinux_xfrm_state_free),
7301 LSM_HOOK_INIT(xfrm_state_delete_security, selinux_xfrm_state_delete),
7302 LSM_HOOK_INIT(xfrm_policy_lookup, selinux_xfrm_policy_lookup),
7303 LSM_HOOK_INIT(xfrm_state_pol_flow_match,
7304 selinux_xfrm_state_pol_flow_match),
7305 LSM_HOOK_INIT(xfrm_decode_session, selinux_xfrm_decode_session),
7306 #endif
7307
7308 #ifdef CONFIG_KEYS
7309 LSM_HOOK_INIT(key_free, selinux_key_free),
7310 LSM_HOOK_INIT(key_permission, selinux_key_permission),
7311 LSM_HOOK_INIT(key_getsecurity, selinux_key_getsecurity),
7312 #ifdef CONFIG_KEY_NOTIFICATIONS
7313 LSM_HOOK_INIT(watch_key, selinux_watch_key),
7314 #endif
7315 #endif
7316
7317 #ifdef CONFIG_AUDIT
7318 LSM_HOOK_INIT(audit_rule_known, selinux_audit_rule_known),
7319 LSM_HOOK_INIT(audit_rule_match, selinux_audit_rule_match),
7320 LSM_HOOK_INIT(audit_rule_free, selinux_audit_rule_free),
7321 #endif
7322
7323 #ifdef CONFIG_BPF_SYSCALL
7324 LSM_HOOK_INIT(bpf, selinux_bpf),
7325 LSM_HOOK_INIT(bpf_map, selinux_bpf_map),
7326 LSM_HOOK_INIT(bpf_prog, selinux_bpf_prog),
7327 LSM_HOOK_INIT(bpf_map_free_security, selinux_bpf_map_free),
7328 LSM_HOOK_INIT(bpf_prog_free_security, selinux_bpf_prog_free),
7329 #endif
7330
7331 #ifdef CONFIG_PERF_EVENTS
7332 LSM_HOOK_INIT(perf_event_open, selinux_perf_event_open),
7333 LSM_HOOK_INIT(perf_event_free, selinux_perf_event_free),
7334 LSM_HOOK_INIT(perf_event_read, selinux_perf_event_read),
7335 LSM_HOOK_INIT(perf_event_write, selinux_perf_event_write),
7336 #endif
7337
7338 #ifdef CONFIG_IO_URING
7339 LSM_HOOK_INIT(uring_override_creds, selinux_uring_override_creds),
7340 LSM_HOOK_INIT(uring_sqpoll, selinux_uring_sqpoll),
7341 LSM_HOOK_INIT(uring_cmd, selinux_uring_cmd),
7342 #endif
7343
7344 /*
7345 * PUT "CLONING" (ACCESSING + ALLOCATING) HOOKS HERE
7346 */
7347 LSM_HOOK_INIT(fs_context_submount, selinux_fs_context_submount),
7348 LSM_HOOK_INIT(fs_context_dup, selinux_fs_context_dup),
7349 LSM_HOOK_INIT(fs_context_parse_param, selinux_fs_context_parse_param),
7350 LSM_HOOK_INIT(sb_eat_lsm_opts, selinux_sb_eat_lsm_opts),
7351 #ifdef CONFIG_SECURITY_NETWORK_XFRM
7352 LSM_HOOK_INIT(xfrm_policy_clone_security, selinux_xfrm_policy_clone),
7353 #endif
7354
7355 /*
7356 * PUT "ALLOCATING" HOOKS HERE
7357 */
7358 LSM_HOOK_INIT(msg_msg_alloc_security, selinux_msg_msg_alloc_security),
7359 LSM_HOOK_INIT(msg_queue_alloc_security,
7360 selinux_msg_queue_alloc_security),
7361 LSM_HOOK_INIT(shm_alloc_security, selinux_shm_alloc_security),
7362 LSM_HOOK_INIT(sb_alloc_security, selinux_sb_alloc_security),
7363 LSM_HOOK_INIT(inode_alloc_security, selinux_inode_alloc_security),
7364 LSM_HOOK_INIT(sem_alloc_security, selinux_sem_alloc_security),
7365 LSM_HOOK_INIT(secid_to_secctx, selinux_secid_to_secctx),
7366 LSM_HOOK_INIT(inode_getsecctx, selinux_inode_getsecctx),
7367 LSM_HOOK_INIT(sk_alloc_security, selinux_sk_alloc_security),
7368 LSM_HOOK_INIT(tun_dev_alloc_security, selinux_tun_dev_alloc_security),
7369 #ifdef CONFIG_SECURITY_INFINIBAND
7370 LSM_HOOK_INIT(ib_alloc_security, selinux_ib_alloc_security),
7371 #endif
7372 #ifdef CONFIG_SECURITY_NETWORK_XFRM
7373 LSM_HOOK_INIT(xfrm_policy_alloc_security, selinux_xfrm_policy_alloc),
7374 LSM_HOOK_INIT(xfrm_state_alloc, selinux_xfrm_state_alloc),
7375 LSM_HOOK_INIT(xfrm_state_alloc_acquire,
7376 selinux_xfrm_state_alloc_acquire),
7377 #endif
7378 #ifdef CONFIG_KEYS
7379 LSM_HOOK_INIT(key_alloc, selinux_key_alloc),
7380 #endif
7381 #ifdef CONFIG_AUDIT
7382 LSM_HOOK_INIT(audit_rule_init, selinux_audit_rule_init),
7383 #endif
7384 #ifdef CONFIG_BPF_SYSCALL
7385 LSM_HOOK_INIT(bpf_map_alloc_security, selinux_bpf_map_alloc),
7386 LSM_HOOK_INIT(bpf_prog_alloc_security, selinux_bpf_prog_alloc),
7387 #endif
7388 #ifdef CONFIG_PERF_EVENTS
7389 LSM_HOOK_INIT(perf_event_alloc, selinux_perf_event_alloc),
7390 #endif
7391 };
7392
selinux_init(void)7393 static __init int selinux_init(void)
7394 {
7395 pr_info("SELinux: Initializing.\n");
7396
7397 memset(&selinux_state, 0, sizeof(selinux_state));
7398 enforcing_set(selinux_enforcing_boot);
7399 selinux_avc_init();
7400 mutex_init(&selinux_state.status_lock);
7401 mutex_init(&selinux_state.policy_mutex);
7402
7403 /* Set the security state for the initial task. */
7404 cred_init_security();
7405
7406 default_noexec = !(VM_DATA_DEFAULT_FLAGS & VM_EXEC);
7407 if (!default_noexec)
7408 pr_notice("SELinux: virtual memory is executable by default\n");
7409
7410 avc_init();
7411
7412 avtab_cache_init();
7413
7414 ebitmap_cache_init();
7415
7416 hashtab_cache_init();
7417
7418 security_add_hooks(selinux_hooks, ARRAY_SIZE(selinux_hooks),
7419 &selinux_lsmid);
7420
7421 if (avc_add_callback(selinux_netcache_avc_callback, AVC_CALLBACK_RESET))
7422 panic("SELinux: Unable to register AVC netcache callback\n");
7423
7424 if (avc_add_callback(selinux_lsm_notifier_avc_callback, AVC_CALLBACK_RESET))
7425 panic("SELinux: Unable to register AVC LSM notifier callback\n");
7426
7427 if (selinux_enforcing_boot)
7428 pr_debug("SELinux: Starting in enforcing mode\n");
7429 else
7430 pr_debug("SELinux: Starting in permissive mode\n");
7431
7432 fs_validate_description("selinux", selinux_fs_parameters);
7433
7434 return 0;
7435 }
7436
delayed_superblock_init(struct super_block * sb,void * unused)7437 static void delayed_superblock_init(struct super_block *sb, void *unused)
7438 {
7439 selinux_set_mnt_opts(sb, NULL, 0, NULL);
7440 }
7441
selinux_complete_init(void)7442 void selinux_complete_init(void)
7443 {
7444 pr_debug("SELinux: Completing initialization.\n");
7445
7446 /* Set up any superblocks initialized prior to the policy load. */
7447 pr_debug("SELinux: Setting up existing superblocks.\n");
7448 iterate_supers(delayed_superblock_init, NULL);
7449 }
7450
7451 /* SELinux requires early initialization in order to label
7452 all processes and objects when they are created. */
7453 DEFINE_LSM(selinux) = {
7454 .name = "selinux",
7455 .flags = LSM_FLAG_LEGACY_MAJOR | LSM_FLAG_EXCLUSIVE,
7456 .enabled = &selinux_enabled_boot,
7457 .blobs = &selinux_blob_sizes,
7458 .init = selinux_init,
7459 };
7460
7461 #if defined(CONFIG_NETFILTER)
7462 static const struct nf_hook_ops selinux_nf_ops[] = {
7463 {
7464 .hook = selinux_ip_postroute,
7465 .pf = NFPROTO_IPV4,
7466 .hooknum = NF_INET_POST_ROUTING,
7467 .priority = NF_IP_PRI_SELINUX_LAST,
7468 },
7469 {
7470 .hook = selinux_ip_forward,
7471 .pf = NFPROTO_IPV4,
7472 .hooknum = NF_INET_FORWARD,
7473 .priority = NF_IP_PRI_SELINUX_FIRST,
7474 },
7475 {
7476 .hook = selinux_ip_output,
7477 .pf = NFPROTO_IPV4,
7478 .hooknum = NF_INET_LOCAL_OUT,
7479 .priority = NF_IP_PRI_SELINUX_FIRST,
7480 },
7481 #if IS_ENABLED(CONFIG_IPV6)
7482 {
7483 .hook = selinux_ip_postroute,
7484 .pf = NFPROTO_IPV6,
7485 .hooknum = NF_INET_POST_ROUTING,
7486 .priority = NF_IP6_PRI_SELINUX_LAST,
7487 },
7488 {
7489 .hook = selinux_ip_forward,
7490 .pf = NFPROTO_IPV6,
7491 .hooknum = NF_INET_FORWARD,
7492 .priority = NF_IP6_PRI_SELINUX_FIRST,
7493 },
7494 {
7495 .hook = selinux_ip_output,
7496 .pf = NFPROTO_IPV6,
7497 .hooknum = NF_INET_LOCAL_OUT,
7498 .priority = NF_IP6_PRI_SELINUX_FIRST,
7499 },
7500 #endif /* IPV6 */
7501 };
7502
selinux_nf_register(struct net * net)7503 static int __net_init selinux_nf_register(struct net *net)
7504 {
7505 return nf_register_net_hooks(net, selinux_nf_ops,
7506 ARRAY_SIZE(selinux_nf_ops));
7507 }
7508
selinux_nf_unregister(struct net * net)7509 static void __net_exit selinux_nf_unregister(struct net *net)
7510 {
7511 nf_unregister_net_hooks(net, selinux_nf_ops,
7512 ARRAY_SIZE(selinux_nf_ops));
7513 }
7514
7515 static struct pernet_operations selinux_net_ops = {
7516 .init = selinux_nf_register,
7517 .exit = selinux_nf_unregister,
7518 };
7519
selinux_nf_ip_init(void)7520 static int __init selinux_nf_ip_init(void)
7521 {
7522 int err;
7523
7524 if (!selinux_enabled_boot)
7525 return 0;
7526
7527 pr_debug("SELinux: Registering netfilter hooks\n");
7528
7529 err = register_pernet_subsys(&selinux_net_ops);
7530 if (err)
7531 panic("SELinux: register_pernet_subsys: error %d\n", err);
7532
7533 return 0;
7534 }
7535 __initcall(selinux_nf_ip_init);
7536 #endif /* CONFIG_NETFILTER */
7537