1 // SPDX-License-Identifier: GPL-2.0-only
2 /*
3 * Integrity Measurement Architecture
4 *
5 * Copyright (C) 2005,2006,2007,2008 IBM Corporation
6 *
7 * Authors:
8 * Reiner Sailer <sailer@watson.ibm.com>
9 * Serge Hallyn <serue@us.ibm.com>
10 * Kylene Hall <kylene@us.ibm.com>
11 * Mimi Zohar <zohar@us.ibm.com>
12 *
13 * File: ima_main.c
14 * implements the IMA hooks: ima_bprm_check, ima_file_mmap,
15 * and ima_file_check.
16 */
17
18 #include <linux/module.h>
19 #include <linux/file.h>
20 #include <linux/binfmts.h>
21 #include <linux/kernel_read_file.h>
22 #include <linux/mount.h>
23 #include <linux/mman.h>
24 #include <linux/slab.h>
25 #include <linux/xattr.h>
26 #include <linux/ima.h>
27 #include <linux/fs.h>
28 #include <linux/iversion.h>
29 #include <linux/evm.h>
30 #include <linux/crash_dump.h>
31
32 #include "ima.h"
33
34 #ifdef CONFIG_IMA_APPRAISE
35 int ima_appraise = IMA_APPRAISE_ENFORCE;
36 #else
37 int ima_appraise;
38 #endif
39
40 int __ro_after_init ima_hash_algo = HASH_ALGO_SHA1;
41 static int hash_setup_done;
42 static int ima_disabled __ro_after_init;
43
44 static struct notifier_block ima_lsm_policy_notifier = {
45 .notifier_call = ima_lsm_policy_change,
46 };
47
ima_setup(char * str)48 static int __init ima_setup(char *str)
49 {
50 if (!is_kdump_kernel()) {
51 pr_info("Warning: ima setup option only permitted in kdump");
52 return 1;
53 }
54
55 if (strncmp(str, "off", 3) == 0)
56 ima_disabled = 1;
57 else if (strncmp(str, "on", 2) == 0)
58 ima_disabled = 0;
59 else
60 pr_err("Invalid ima setup option: \"%s\" , please specify ima=on|off.", str);
61
62 return 1;
63 }
64 __setup("ima=", ima_setup);
65
hash_setup(char * str)66 static int __init hash_setup(char *str)
67 {
68 struct ima_template_desc *template_desc = ima_template_desc_current();
69 int i;
70
71 if (hash_setup_done)
72 return 1;
73
74 if (strcmp(template_desc->name, IMA_TEMPLATE_IMA_NAME) == 0) {
75 if (strncmp(str, "sha1", 4) == 0) {
76 ima_hash_algo = HASH_ALGO_SHA1;
77 } else if (strncmp(str, "md5", 3) == 0) {
78 ima_hash_algo = HASH_ALGO_MD5;
79 } else {
80 pr_err("invalid hash algorithm \"%s\" for template \"%s\"",
81 str, IMA_TEMPLATE_IMA_NAME);
82 return 1;
83 }
84 goto out;
85 }
86
87 i = match_string(hash_algo_name, HASH_ALGO__LAST, str);
88 if (i < 0) {
89 pr_err("invalid hash algorithm \"%s\"", str);
90 return 1;
91 }
92
93 ima_hash_algo = i;
94 out:
95 hash_setup_done = 1;
96 return 1;
97 }
98 __setup("ima_hash=", hash_setup);
99
ima_get_current_hash_algo(void)100 enum hash_algo ima_get_current_hash_algo(void)
101 {
102 return ima_hash_algo;
103 }
104
105 /* Prevent mmap'ing a file execute that is already mmap'ed write */
mmap_violation_check(enum ima_hooks func,struct file * file,char ** pathbuf,const char ** pathname,char * filename)106 static int mmap_violation_check(enum ima_hooks func, struct file *file,
107 char **pathbuf, const char **pathname,
108 char *filename)
109 {
110 struct inode *inode;
111 int rc = 0;
112
113 if ((func == MMAP_CHECK || func == MMAP_CHECK_REQPROT) &&
114 mapping_writably_mapped(file->f_mapping)) {
115 rc = -ETXTBSY;
116 inode = file_inode(file);
117
118 if (!*pathbuf) /* ima_rdwr_violation possibly pre-fetched */
119 *pathname = ima_d_path(&file->f_path, pathbuf,
120 filename);
121 integrity_audit_msg(AUDIT_INTEGRITY_DATA, inode, *pathname,
122 "mmap_file", "mmapped_writers", rc, 0);
123 }
124 return rc;
125 }
126
127 /*
128 * ima_rdwr_violation_check
129 *
130 * Only invalidate the PCR for measured files:
131 * - Opening a file for write when already open for read,
132 * results in a time of measure, time of use (ToMToU) error.
133 * - Opening a file for read when already open for write,
134 * could result in a file measurement error.
135 *
136 */
ima_rdwr_violation_check(struct file * file,struct ima_iint_cache * iint,int must_measure,char ** pathbuf,const char ** pathname,char * filename)137 static void ima_rdwr_violation_check(struct file *file,
138 struct ima_iint_cache *iint,
139 int must_measure,
140 char **pathbuf,
141 const char **pathname,
142 char *filename)
143 {
144 struct inode *inode = file_inode(file);
145 fmode_t mode = file->f_mode;
146 bool send_tomtou = false, send_writers = false;
147
148 if (mode & FMODE_WRITE) {
149 if (atomic_read(&inode->i_readcount) && IS_IMA(inode)) {
150 if (!iint)
151 iint = ima_iint_find(inode);
152
153 /* IMA_MEASURE is set from reader side */
154 if (iint && test_and_clear_bit(IMA_MAY_EMIT_TOMTOU,
155 &iint->atomic_flags))
156 send_tomtou = true;
157 }
158 } else {
159 if (must_measure)
160 set_bit(IMA_MAY_EMIT_TOMTOU, &iint->atomic_flags);
161
162 /* Limit number of open_writers violations */
163 if (inode_is_open_for_write(inode) && must_measure) {
164 if (!test_and_set_bit(IMA_EMITTED_OPENWRITERS,
165 &iint->atomic_flags))
166 send_writers = true;
167 }
168 }
169
170 if (!send_tomtou && !send_writers)
171 return;
172
173 *pathname = ima_d_path(&file->f_path, pathbuf, filename);
174
175 if (send_tomtou)
176 ima_add_violation(file, *pathname, iint,
177 "invalid_pcr", "ToMToU");
178 if (send_writers)
179 ima_add_violation(file, *pathname, iint,
180 "invalid_pcr", "open_writers");
181 }
182
ima_check_last_writer(struct ima_iint_cache * iint,struct inode * inode,struct file * file)183 static void ima_check_last_writer(struct ima_iint_cache *iint,
184 struct inode *inode, struct file *file)
185 {
186 fmode_t mode = file->f_mode;
187 bool update;
188
189 if (!(mode & FMODE_WRITE))
190 return;
191
192 mutex_lock(&iint->mutex);
193 if (atomic_read(&inode->i_writecount) == 1) {
194 struct kstat stat;
195
196 clear_bit(IMA_EMITTED_OPENWRITERS, &iint->atomic_flags);
197
198 update = test_and_clear_bit(IMA_UPDATE_XATTR,
199 &iint->atomic_flags);
200 if ((iint->flags & IMA_NEW_FILE) ||
201 vfs_getattr_nosec(&file->f_path, &stat,
202 STATX_CHANGE_COOKIE,
203 AT_STATX_SYNC_AS_STAT) ||
204 !(stat.result_mask & STATX_CHANGE_COOKIE) ||
205 stat.change_cookie != iint->real_inode.version) {
206 iint->flags &= ~(IMA_DONE_MASK | IMA_NEW_FILE);
207 iint->measured_pcrs = 0;
208 if (update)
209 ima_update_xattr(iint, file);
210 }
211 }
212 mutex_unlock(&iint->mutex);
213 }
214
215 /**
216 * ima_file_free - called on __fput()
217 * @file: pointer to file structure being freed
218 *
219 * Flag files that changed, based on i_version
220 */
ima_file_free(struct file * file)221 static void ima_file_free(struct file *file)
222 {
223 struct inode *inode = file_inode(file);
224 struct ima_iint_cache *iint;
225
226 if (!ima_policy_flag || !S_ISREG(inode->i_mode))
227 return;
228
229 iint = ima_iint_find(inode);
230 if (!iint)
231 return;
232
233 ima_check_last_writer(iint, inode, file);
234 }
235
process_measurement(struct file * file,const struct cred * cred,struct lsm_prop * prop,char * buf,loff_t size,int mask,enum ima_hooks func)236 static int process_measurement(struct file *file, const struct cred *cred,
237 struct lsm_prop *prop, char *buf, loff_t size,
238 int mask, enum ima_hooks func)
239 {
240 struct inode *real_inode, *inode = file_inode(file);
241 struct ima_iint_cache *iint = NULL;
242 struct ima_template_desc *template_desc = NULL;
243 struct inode *metadata_inode;
244 char *pathbuf = NULL;
245 char filename[NAME_MAX];
246 const char *pathname = NULL;
247 int rc = 0, action, must_appraise = 0;
248 int pcr = CONFIG_IMA_MEASURE_PCR_IDX;
249 struct evm_ima_xattr_data *xattr_value = NULL;
250 struct modsig *modsig = NULL;
251 int xattr_len = 0;
252 bool violation_check;
253 enum hash_algo hash_algo;
254 unsigned int allowed_algos = 0;
255
256 if (!ima_policy_flag || !S_ISREG(inode->i_mode))
257 return 0;
258
259 /* Return an IMA_MEASURE, IMA_APPRAISE, IMA_AUDIT action
260 * bitmask based on the appraise/audit/measurement policy.
261 * Included is the appraise submask.
262 */
263 action = ima_get_action(file_mnt_idmap(file), inode, cred, prop,
264 mask, func, &pcr, &template_desc, NULL,
265 &allowed_algos);
266 violation_check = ((func == FILE_CHECK || func == MMAP_CHECK ||
267 func == MMAP_CHECK_REQPROT) &&
268 (ima_policy_flag & IMA_MEASURE) &&
269 ((action & IMA_MEASURE) ||
270 (file->f_mode & FMODE_WRITE)));
271 if (!action && !violation_check)
272 return 0;
273
274 must_appraise = action & IMA_APPRAISE;
275
276 /* Is the appraise rule hook specific? */
277 if (action & IMA_FILE_APPRAISE)
278 func = FILE_CHECK;
279
280 inode_lock(inode);
281
282 if (action) {
283 iint = ima_inode_get(inode);
284 if (!iint)
285 rc = -ENOMEM;
286 }
287
288 if (!rc && violation_check)
289 ima_rdwr_violation_check(file, iint, action & IMA_MEASURE,
290 &pathbuf, &pathname, filename);
291
292 inode_unlock(inode);
293
294 if (rc)
295 goto out;
296 if (!action)
297 goto out;
298
299 mutex_lock(&iint->mutex);
300
301 if (test_and_clear_bit(IMA_CHANGE_ATTR, &iint->atomic_flags))
302 /*
303 * Reset appraisal flags (action and non-action rule-specific)
304 * if ima_inode_post_setattr was called.
305 */
306 iint->flags &= ~(IMA_APPRAISE | IMA_APPRAISED |
307 IMA_APPRAISE_SUBMASK | IMA_APPRAISED_SUBMASK |
308 IMA_NONACTION_RULE_FLAGS);
309
310 /*
311 * Re-evaulate the file if either the xattr has changed or the
312 * kernel has no way of detecting file change on the filesystem.
313 * (Limited to privileged mounted filesystems.)
314 */
315 if (test_and_clear_bit(IMA_CHANGE_XATTR, &iint->atomic_flags) ||
316 ((inode->i_sb->s_iflags & SB_I_IMA_UNVERIFIABLE_SIGNATURE) &&
317 !(inode->i_sb->s_iflags & SB_I_UNTRUSTED_MOUNTER) &&
318 !(action & IMA_FAIL_UNVERIFIABLE_SIGS))) {
319 iint->flags &= ~IMA_DONE_MASK;
320 iint->measured_pcrs = 0;
321 }
322
323 /*
324 * On stacked filesystems, detect and re-evaluate file data and
325 * metadata changes.
326 */
327 real_inode = d_real_inode(file_dentry(file));
328 if (real_inode != inode &&
329 (action & IMA_DO_MASK) && (iint->flags & IMA_DONE_MASK)) {
330 if (!IS_I_VERSION(real_inode) ||
331 integrity_inode_attrs_changed(&iint->real_inode,
332 real_inode)) {
333 iint->flags &= ~IMA_DONE_MASK;
334 iint->measured_pcrs = 0;
335 }
336
337 /*
338 * Reset the EVM status when metadata changed.
339 */
340 metadata_inode = d_inode(d_real(file_dentry(file),
341 D_REAL_METADATA));
342 if (evm_metadata_changed(inode, metadata_inode))
343 iint->flags &= ~(IMA_APPRAISED |
344 IMA_APPRAISED_SUBMASK);
345 }
346
347 /* Determine if already appraised/measured based on bitmask
348 * (IMA_MEASURE, IMA_MEASURED, IMA_XXXX_APPRAISE, IMA_XXXX_APPRAISED,
349 * IMA_AUDIT, IMA_AUDITED)
350 */
351 iint->flags |= action;
352 action &= IMA_DO_MASK;
353 action &= ~((iint->flags & (IMA_DONE_MASK ^ IMA_MEASURED)) >> 1);
354
355 /* If target pcr is already measured, unset IMA_MEASURE action */
356 if ((action & IMA_MEASURE) && (iint->measured_pcrs & (0x1 << pcr)))
357 action ^= IMA_MEASURE;
358
359 /* HASH sets the digital signature and update flags, nothing else */
360 if ((action & IMA_HASH) &&
361 !(test_bit(IMA_DIGSIG, &iint->atomic_flags))) {
362 xattr_len = ima_read_xattr(file_dentry(file),
363 &xattr_value, xattr_len);
364 if ((xattr_value && xattr_len > 2) &&
365 (xattr_value->type == EVM_IMA_XATTR_DIGSIG))
366 set_bit(IMA_DIGSIG, &iint->atomic_flags);
367 iint->flags |= IMA_HASHED;
368 action ^= IMA_HASH;
369 set_bit(IMA_UPDATE_XATTR, &iint->atomic_flags);
370 }
371
372 /* Nothing to do, just return existing appraised status */
373 if (!action) {
374 if (must_appraise) {
375 rc = mmap_violation_check(func, file, &pathbuf,
376 &pathname, filename);
377 if (!rc)
378 rc = ima_get_cache_status(iint, func);
379 }
380 goto out_locked;
381 }
382
383 if ((action & IMA_APPRAISE_SUBMASK) ||
384 strcmp(template_desc->name, IMA_TEMPLATE_IMA_NAME) != 0) {
385 /* read 'security.ima' */
386 xattr_len = ima_read_xattr(file_dentry(file),
387 &xattr_value, xattr_len);
388
389 /*
390 * Read the appended modsig if allowed by the policy, and allow
391 * an additional measurement list entry, if needed, based on the
392 * template format and whether the file was already measured.
393 */
394 if (iint->flags & IMA_MODSIG_ALLOWED) {
395 rc = ima_read_modsig(func, buf, size, &modsig);
396
397 if (!rc && ima_template_has_modsig(template_desc) &&
398 iint->flags & IMA_MEASURED)
399 action |= IMA_MEASURE;
400 }
401 }
402
403 hash_algo = ima_get_hash_algo(xattr_value, xattr_len);
404
405 rc = ima_collect_measurement(iint, file, buf, size, hash_algo, modsig);
406 if (rc != 0 && rc != -EBADF && rc != -EINVAL)
407 goto out_locked;
408
409 if (!pathbuf) /* ima_rdwr_violation possibly pre-fetched */
410 pathname = ima_d_path(&file->f_path, &pathbuf, filename);
411
412 if (action & IMA_MEASURE)
413 ima_store_measurement(iint, file, pathname,
414 xattr_value, xattr_len, modsig, pcr,
415 template_desc);
416 if (rc == 0 && (action & IMA_APPRAISE_SUBMASK)) {
417 rc = ima_check_blacklist(iint, modsig, pcr);
418 if (rc != -EPERM) {
419 inode_lock(inode);
420 rc = ima_appraise_measurement(func, iint, file,
421 pathname, xattr_value,
422 xattr_len, modsig);
423 inode_unlock(inode);
424 }
425 if (!rc)
426 rc = mmap_violation_check(func, file, &pathbuf,
427 &pathname, filename);
428 }
429 if (action & IMA_AUDIT)
430 ima_audit_measurement(iint, pathname);
431
432 if ((file->f_flags & O_DIRECT) && (iint->flags & IMA_PERMIT_DIRECTIO))
433 rc = 0;
434
435 /* Ensure the digest was generated using an allowed algorithm */
436 if (rc == 0 && must_appraise && allowed_algos != 0 &&
437 (allowed_algos & (1U << hash_algo)) == 0) {
438 rc = -EACCES;
439
440 integrity_audit_msg(AUDIT_INTEGRITY_DATA, file_inode(file),
441 pathname, "collect_data",
442 "denied-hash-algorithm", rc, 0);
443 }
444 out_locked:
445 if ((mask & MAY_WRITE) && test_bit(IMA_DIGSIG, &iint->atomic_flags) &&
446 !(iint->flags & IMA_NEW_FILE))
447 rc = -EACCES;
448 mutex_unlock(&iint->mutex);
449 kfree(xattr_value);
450 ima_free_modsig(modsig);
451 out:
452 if (pathbuf)
453 __putname(pathbuf);
454 if (must_appraise) {
455 if (rc && (ima_appraise & IMA_APPRAISE_ENFORCE))
456 return -EACCES;
457 if (file->f_mode & FMODE_WRITE)
458 set_bit(IMA_UPDATE_XATTR, &iint->atomic_flags);
459 }
460 return 0;
461 }
462
463 /**
464 * ima_file_mmap - based on policy, collect/store measurement.
465 * @file: pointer to the file to be measured (May be NULL)
466 * @reqprot: protection requested by the application
467 * @prot: protection that will be applied by the kernel
468 * @flags: operational flags
469 *
470 * Measure files being mmapped executable based on the ima_must_measure()
471 * policy decision.
472 *
473 * On success return 0. On integrity appraisal error, assuming the file
474 * is in policy and IMA-appraisal is in enforcing mode, return -EACCES.
475 */
ima_file_mmap(struct file * file,unsigned long reqprot,unsigned long prot,unsigned long flags)476 static int ima_file_mmap(struct file *file, unsigned long reqprot,
477 unsigned long prot, unsigned long flags)
478 {
479 struct lsm_prop prop;
480 int ret;
481
482 if (!file)
483 return 0;
484
485 security_current_getlsmprop_subj(&prop);
486
487 if (reqprot & PROT_EXEC) {
488 ret = process_measurement(file, current_cred(), &prop, NULL,
489 0, MAY_EXEC, MMAP_CHECK_REQPROT);
490 if (ret)
491 return ret;
492 }
493
494 if (prot & PROT_EXEC)
495 return process_measurement(file, current_cred(), &prop, NULL,
496 0, MAY_EXEC, MMAP_CHECK);
497
498 return 0;
499 }
500
501 /**
502 * ima_file_mprotect - based on policy, limit mprotect change
503 * @vma: vm_area_struct protection is set to
504 * @reqprot: protection requested by the application
505 * @prot: protection that will be applied by the kernel
506 *
507 * Files can be mmap'ed read/write and later changed to execute to circumvent
508 * IMA's mmap appraisal policy rules. Due to locking issues (mmap semaphore
509 * would be taken before i_mutex), files can not be measured or appraised at
510 * this point. Eliminate this integrity gap by denying the mprotect
511 * PROT_EXECUTE change, if an mmap appraise policy rule exists.
512 *
513 * On mprotect change success, return 0. On failure, return -EACESS.
514 */
ima_file_mprotect(struct vm_area_struct * vma,unsigned long reqprot,unsigned long prot)515 static int ima_file_mprotect(struct vm_area_struct *vma, unsigned long reqprot,
516 unsigned long prot)
517 {
518 struct ima_template_desc *template = NULL;
519 struct file *file;
520 char filename[NAME_MAX];
521 char *pathbuf = NULL;
522 const char *pathname = NULL;
523 struct inode *inode;
524 struct lsm_prop prop;
525 int result = 0;
526 int action;
527 int pcr;
528
529 /* Is mprotect making an mmap'ed file executable? */
530 if (!(ima_policy_flag & IMA_APPRAISE) || !vma->vm_file ||
531 !(prot & PROT_EXEC) || (vma->vm_flags & VM_EXEC))
532 return 0;
533
534 security_current_getlsmprop_subj(&prop);
535 inode = file_inode(vma->vm_file);
536 action = ima_get_action(file_mnt_idmap(vma->vm_file), inode,
537 current_cred(), &prop, MAY_EXEC, MMAP_CHECK,
538 &pcr, &template, NULL, NULL);
539 action |= ima_get_action(file_mnt_idmap(vma->vm_file), inode,
540 current_cred(), &prop, MAY_EXEC,
541 MMAP_CHECK_REQPROT, &pcr, &template, NULL,
542 NULL);
543
544 /* Is the mmap'ed file in policy? */
545 if (!(action & (IMA_MEASURE | IMA_APPRAISE_SUBMASK)))
546 return 0;
547
548 if (action & IMA_APPRAISE_SUBMASK)
549 result = -EPERM;
550
551 file = vma->vm_file;
552 pathname = ima_d_path(&file->f_path, &pathbuf, filename);
553 integrity_audit_msg(AUDIT_INTEGRITY_DATA, inode, pathname,
554 "collect_data", "failed-mprotect", result, 0);
555 if (pathbuf)
556 __putname(pathbuf);
557
558 return result;
559 }
560
561 /**
562 * ima_bprm_check - based on policy, collect/store measurement.
563 * @bprm: contains the linux_binprm structure
564 *
565 * The OS protects against an executable file, already open for write,
566 * from being executed in deny_write_access() and an executable file,
567 * already open for execute, from being modified in get_write_access().
568 * So we can be certain that what we verify and measure here is actually
569 * what is being executed.
570 *
571 * On success return 0. On integrity appraisal error, assuming the file
572 * is in policy and IMA-appraisal is in enforcing mode, return -EACCES.
573 */
ima_bprm_check(struct linux_binprm * bprm)574 static int ima_bprm_check(struct linux_binprm *bprm)
575 {
576 int ret;
577 struct lsm_prop prop;
578
579 security_current_getlsmprop_subj(&prop);
580 ret = process_measurement(bprm->file, current_cred(),
581 &prop, NULL, 0, MAY_EXEC, BPRM_CHECK);
582 if (ret)
583 return ret;
584
585 security_cred_getlsmprop(bprm->cred, &prop);
586 return process_measurement(bprm->file, bprm->cred, &prop, NULL, 0,
587 MAY_EXEC, CREDS_CHECK);
588 }
589
590 /**
591 * ima_bprm_creds_for_exec - collect/store/appraise measurement.
592 * @bprm: contains the linux_binprm structure
593 *
594 * Based on the IMA policy and the execveat(2) AT_EXECVE_CHECK flag, measure
595 * and appraise the integrity of a file to be executed by script interpreters.
596 * Unlike any of the other LSM hooks where the kernel enforces file integrity,
597 * enforcing file integrity is left up to the discretion of the script
598 * interpreter (userspace).
599 *
600 * On success return 0. On integrity appraisal error, assuming the file
601 * is in policy and IMA-appraisal is in enforcing mode, return -EACCES.
602 */
ima_bprm_creds_for_exec(struct linux_binprm * bprm)603 static int ima_bprm_creds_for_exec(struct linux_binprm *bprm)
604 {
605 /*
606 * As security_bprm_check() is called multiple times, both
607 * the script and the shebang interpreter are measured, appraised,
608 * and audited. Limit usage of this LSM hook to just measuring,
609 * appraising, and auditing the indirect script execution
610 * (e.g. ./sh example.sh).
611 */
612 if (!bprm->is_check)
613 return 0;
614
615 return ima_bprm_check(bprm);
616 }
617
618 /**
619 * ima_file_check - based on policy, collect/store measurement.
620 * @file: pointer to the file to be measured
621 * @mask: contains MAY_READ, MAY_WRITE, MAY_EXEC or MAY_APPEND
622 *
623 * Measure files based on the ima_must_measure() policy decision.
624 *
625 * On success return 0. On integrity appraisal error, assuming the file
626 * is in policy and IMA-appraisal is in enforcing mode, return -EACCES.
627 */
ima_file_check(struct file * file,int mask)628 static int ima_file_check(struct file *file, int mask)
629 {
630 struct lsm_prop prop;
631
632 security_current_getlsmprop_subj(&prop);
633 return process_measurement(file, current_cred(), &prop, NULL, 0,
634 mask & (MAY_READ | MAY_WRITE | MAY_EXEC |
635 MAY_APPEND), FILE_CHECK);
636 }
637
__ima_inode_hash(struct inode * inode,struct file * file,char * buf,size_t buf_size)638 static int __ima_inode_hash(struct inode *inode, struct file *file, char *buf,
639 size_t buf_size)
640 {
641 struct ima_iint_cache *iint = NULL, tmp_iint;
642 int rc, hash_algo;
643
644 if (ima_policy_flag) {
645 iint = ima_iint_find(inode);
646 if (iint)
647 mutex_lock(&iint->mutex);
648 }
649
650 if ((!iint || !(iint->flags & IMA_COLLECTED)) && file) {
651 if (iint)
652 mutex_unlock(&iint->mutex);
653
654 memset(&tmp_iint, 0, sizeof(tmp_iint));
655 mutex_init(&tmp_iint.mutex);
656
657 rc = ima_collect_measurement(&tmp_iint, file, NULL, 0,
658 ima_hash_algo, NULL);
659 if (rc < 0) {
660 /* ima_hash could be allocated in case of failure. */
661 if (rc != -ENOMEM)
662 kfree(tmp_iint.ima_hash);
663
664 return -EOPNOTSUPP;
665 }
666
667 iint = &tmp_iint;
668 mutex_lock(&iint->mutex);
669 }
670
671 if (!iint)
672 return -EOPNOTSUPP;
673
674 /*
675 * ima_file_hash can be called when ima_collect_measurement has still
676 * not been called, we might not always have a hash.
677 */
678 if (!iint->ima_hash || !(iint->flags & IMA_COLLECTED)) {
679 mutex_unlock(&iint->mutex);
680 return -EOPNOTSUPP;
681 }
682
683 if (buf) {
684 size_t copied_size;
685
686 copied_size = min_t(size_t, iint->ima_hash->length, buf_size);
687 memcpy(buf, iint->ima_hash->digest, copied_size);
688 }
689 hash_algo = iint->ima_hash->algo;
690 mutex_unlock(&iint->mutex);
691
692 if (iint == &tmp_iint)
693 kfree(iint->ima_hash);
694
695 return hash_algo;
696 }
697
698 /**
699 * ima_file_hash - return a measurement of the file
700 * @file: pointer to the file
701 * @buf: buffer in which to store the hash
702 * @buf_size: length of the buffer
703 *
704 * On success, return the hash algorithm (as defined in the enum hash_algo).
705 * If buf is not NULL, this function also outputs the hash into buf.
706 * If the hash is larger than buf_size, then only buf_size bytes will be copied.
707 * It generally just makes sense to pass a buffer capable of holding the largest
708 * possible hash: IMA_MAX_DIGEST_SIZE.
709 * The file hash returned is based on the entire file, including the appended
710 * signature.
711 *
712 * If the measurement cannot be performed, return -EOPNOTSUPP.
713 * If the parameters are incorrect, return -EINVAL.
714 */
ima_file_hash(struct file * file,char * buf,size_t buf_size)715 int ima_file_hash(struct file *file, char *buf, size_t buf_size)
716 {
717 if (!file)
718 return -EINVAL;
719
720 return __ima_inode_hash(file_inode(file), file, buf, buf_size);
721 }
722 EXPORT_SYMBOL_GPL(ima_file_hash);
723
724 /**
725 * ima_inode_hash - return the stored measurement if the inode has been hashed
726 * and is in the iint cache.
727 * @inode: pointer to the inode
728 * @buf: buffer in which to store the hash
729 * @buf_size: length of the buffer
730 *
731 * On success, return the hash algorithm (as defined in the enum hash_algo).
732 * If buf is not NULL, this function also outputs the hash into buf.
733 * If the hash is larger than buf_size, then only buf_size bytes will be copied.
734 * It generally just makes sense to pass a buffer capable of holding the largest
735 * possible hash: IMA_MAX_DIGEST_SIZE.
736 * The hash returned is based on the entire contents, including the appended
737 * signature.
738 *
739 * If IMA is disabled or if no measurement is available, return -EOPNOTSUPP.
740 * If the parameters are incorrect, return -EINVAL.
741 */
ima_inode_hash(struct inode * inode,char * buf,size_t buf_size)742 int ima_inode_hash(struct inode *inode, char *buf, size_t buf_size)
743 {
744 if (!inode)
745 return -EINVAL;
746
747 return __ima_inode_hash(inode, NULL, buf, buf_size);
748 }
749 EXPORT_SYMBOL_GPL(ima_inode_hash);
750
751 /**
752 * ima_post_create_tmpfile - mark newly created tmpfile as new
753 * @idmap: idmap of the mount the inode was found from
754 * @inode: inode of the newly created tmpfile
755 *
756 * No measuring, appraising or auditing of newly created tmpfiles is needed.
757 * Skip calling process_measurement(), but indicate which newly, created
758 * tmpfiles are in policy.
759 */
ima_post_create_tmpfile(struct mnt_idmap * idmap,struct inode * inode)760 static void ima_post_create_tmpfile(struct mnt_idmap *idmap,
761 struct inode *inode)
762
763 {
764 struct ima_iint_cache *iint;
765 int must_appraise;
766
767 if (!ima_policy_flag || !S_ISREG(inode->i_mode))
768 return;
769
770 must_appraise = ima_must_appraise(idmap, inode, MAY_ACCESS,
771 FILE_CHECK);
772 if (!must_appraise)
773 return;
774
775 /* Nothing to do if we can't allocate memory */
776 iint = ima_inode_get(inode);
777 if (!iint)
778 return;
779
780 /* needed for writing the security xattrs */
781 set_bit(IMA_UPDATE_XATTR, &iint->atomic_flags);
782 iint->ima_file_status = INTEGRITY_PASS;
783 }
784
785 /**
786 * ima_post_path_mknod - mark as a new inode
787 * @idmap: idmap of the mount the inode was found from
788 * @dentry: newly created dentry
789 *
790 * Mark files created via the mknodat syscall as new, so that the
791 * file data can be written later.
792 */
ima_post_path_mknod(struct mnt_idmap * idmap,struct dentry * dentry)793 static void ima_post_path_mknod(struct mnt_idmap *idmap, struct dentry *dentry)
794 {
795 struct ima_iint_cache *iint;
796 struct inode *inode = dentry->d_inode;
797 int must_appraise;
798
799 if (!ima_policy_flag || !S_ISREG(inode->i_mode))
800 return;
801
802 must_appraise = ima_must_appraise(idmap, inode, MAY_ACCESS,
803 FILE_CHECK);
804 if (!must_appraise)
805 return;
806
807 /* Nothing to do if we can't allocate memory */
808 iint = ima_inode_get(inode);
809 if (!iint)
810 return;
811
812 /* needed for re-opening empty files */
813 iint->flags |= IMA_NEW_FILE;
814 }
815
816 /**
817 * ima_read_file - pre-measure/appraise hook decision based on policy
818 * @file: pointer to the file to be measured/appraised/audit
819 * @read_id: caller identifier
820 * @contents: whether a subsequent call will be made to ima_post_read_file()
821 *
822 * Permit reading a file based on policy. The policy rules are written
823 * in terms of the policy identifier. Appraising the integrity of
824 * a file requires a file descriptor.
825 *
826 * For permission return 0, otherwise return -EACCES.
827 */
ima_read_file(struct file * file,enum kernel_read_file_id read_id,bool contents)828 static int ima_read_file(struct file *file, enum kernel_read_file_id read_id,
829 bool contents)
830 {
831 enum ima_hooks func;
832 struct lsm_prop prop;
833
834 /*
835 * Do devices using pre-allocated memory run the risk of the
836 * firmware being accessible to the device prior to the completion
837 * of IMA's signature verification any more than when using two
838 * buffers? It may be desirable to include the buffer address
839 * in this API and walk all the dma_map_single() mappings to check.
840 */
841
842 /*
843 * There will be a call made to ima_post_read_file() with
844 * a filled buffer, so we don't need to perform an extra
845 * read early here.
846 */
847 if (contents)
848 return 0;
849
850 /* Read entire file for all partial reads. */
851 func = read_idmap[read_id] ?: FILE_CHECK;
852 security_current_getlsmprop_subj(&prop);
853 return process_measurement(file, current_cred(), &prop, NULL, 0,
854 MAY_READ, func);
855 }
856
857 const int read_idmap[READING_MAX_ID] = {
858 [READING_FIRMWARE] = FIRMWARE_CHECK,
859 [READING_MODULE] = MODULE_CHECK,
860 [READING_KEXEC_IMAGE] = KEXEC_KERNEL_CHECK,
861 [READING_KEXEC_INITRAMFS] = KEXEC_INITRAMFS_CHECK,
862 [READING_POLICY] = POLICY_CHECK
863 };
864
865 /**
866 * ima_post_read_file - in memory collect/appraise/audit measurement
867 * @file: pointer to the file to be measured/appraised/audit
868 * @buf: pointer to in memory file contents
869 * @size: size of in memory file contents
870 * @read_id: caller identifier
871 *
872 * Measure/appraise/audit in memory file based on policy. Policy rules
873 * are written in terms of a policy identifier.
874 *
875 * On success return 0. On integrity appraisal error, assuming the file
876 * is in policy and IMA-appraisal is in enforcing mode, return -EACCES.
877 */
ima_post_read_file(struct file * file,char * buf,loff_t size,enum kernel_read_file_id read_id)878 static int ima_post_read_file(struct file *file, char *buf, loff_t size,
879 enum kernel_read_file_id read_id)
880 {
881 enum ima_hooks func;
882 struct lsm_prop prop;
883
884 /* permit signed certs */
885 if (!file && read_id == READING_X509_CERTIFICATE)
886 return 0;
887
888 if (!file || !buf || size == 0) { /* should never happen */
889 if (ima_appraise & IMA_APPRAISE_ENFORCE)
890 return -EACCES;
891 return 0;
892 }
893
894 func = read_idmap[read_id] ?: FILE_CHECK;
895 security_current_getlsmprop_subj(&prop);
896 return process_measurement(file, current_cred(), &prop, buf, size,
897 MAY_READ, func);
898 }
899
900 /**
901 * ima_load_data - appraise decision based on policy
902 * @id: kernel load data caller identifier
903 * @contents: whether the full contents will be available in a later
904 * call to ima_post_load_data().
905 *
906 * Callers of this LSM hook can not measure, appraise, or audit the
907 * data provided by userspace. Enforce policy rules requiring a file
908 * signature (eg. kexec'ed kernel image).
909 *
910 * For permission return 0, otherwise return -EACCES.
911 */
ima_load_data(enum kernel_load_data_id id,bool contents)912 static int ima_load_data(enum kernel_load_data_id id, bool contents)
913 {
914 bool ima_enforce, sig_enforce;
915
916 ima_enforce =
917 (ima_appraise & IMA_APPRAISE_ENFORCE) == IMA_APPRAISE_ENFORCE;
918
919 switch (id) {
920 case LOADING_KEXEC_IMAGE:
921 if (IS_ENABLED(CONFIG_KEXEC_SIG)
922 && arch_ima_get_secureboot()) {
923 pr_err("impossible to appraise a kernel image without a file descriptor; try using kexec_file_load syscall.\n");
924 return -EACCES;
925 }
926
927 if (ima_enforce && (ima_appraise & IMA_APPRAISE_KEXEC)) {
928 pr_err("impossible to appraise a kernel image without a file descriptor; try using kexec_file_load syscall.\n");
929 return -EACCES; /* INTEGRITY_UNKNOWN */
930 }
931 break;
932 case LOADING_FIRMWARE:
933 if (ima_enforce && (ima_appraise & IMA_APPRAISE_FIRMWARE) && !contents) {
934 pr_err("Prevent firmware sysfs fallback loading.\n");
935 return -EACCES; /* INTEGRITY_UNKNOWN */
936 }
937 break;
938 case LOADING_MODULE:
939 sig_enforce = is_module_sig_enforced();
940
941 if (ima_enforce && (!sig_enforce
942 && (ima_appraise & IMA_APPRAISE_MODULES))) {
943 pr_err("impossible to appraise a module without a file descriptor. sig_enforce kernel parameter might help\n");
944 return -EACCES; /* INTEGRITY_UNKNOWN */
945 }
946 break;
947 default:
948 break;
949 }
950 return 0;
951 }
952
953 /**
954 * ima_post_load_data - appraise decision based on policy
955 * @buf: pointer to in memory file contents
956 * @size: size of in memory file contents
957 * @load_id: kernel load data caller identifier
958 * @description: @load_id-specific description of contents
959 *
960 * Measure/appraise/audit in memory buffer based on policy. Policy rules
961 * are written in terms of a policy identifier.
962 *
963 * On success return 0. On integrity appraisal error, assuming the file
964 * is in policy and IMA-appraisal is in enforcing mode, return -EACCES.
965 */
ima_post_load_data(char * buf,loff_t size,enum kernel_load_data_id load_id,char * description)966 static int ima_post_load_data(char *buf, loff_t size,
967 enum kernel_load_data_id load_id,
968 char *description)
969 {
970 if (load_id == LOADING_FIRMWARE) {
971 if ((ima_appraise & IMA_APPRAISE_FIRMWARE) &&
972 (ima_appraise & IMA_APPRAISE_ENFORCE)) {
973 pr_err("Prevent firmware loading_store.\n");
974 return -EACCES; /* INTEGRITY_UNKNOWN */
975 }
976 return 0;
977 }
978
979 /*
980 * Measure the init_module syscall buffer containing the ELF image.
981 */
982 if (load_id == LOADING_MODULE)
983 ima_measure_critical_data("modules", "init_module",
984 buf, size, true, NULL, 0);
985
986 return 0;
987 }
988
989 /**
990 * process_buffer_measurement - Measure the buffer or the buffer data hash
991 * @idmap: idmap of the mount the inode was found from
992 * @inode: inode associated with the object being measured (NULL for KEY_CHECK)
993 * @buf: pointer to the buffer that needs to be added to the log.
994 * @size: size of buffer(in bytes).
995 * @eventname: event name to be used for the buffer entry.
996 * @func: IMA hook
997 * @pcr: pcr to extend the measurement
998 * @func_data: func specific data, may be NULL
999 * @buf_hash: measure buffer data hash
1000 * @digest: buffer digest will be written to
1001 * @digest_len: buffer length
1002 *
1003 * Based on policy, either the buffer data or buffer data hash is measured
1004 *
1005 * Return: 0 if the buffer has been successfully measured, 1 if the digest
1006 * has been written to the passed location but not added to a measurement entry,
1007 * a negative value otherwise.
1008 */
process_buffer_measurement(struct mnt_idmap * idmap,struct inode * inode,const void * buf,int size,const char * eventname,enum ima_hooks func,int pcr,const char * func_data,bool buf_hash,u8 * digest,size_t digest_len)1009 int process_buffer_measurement(struct mnt_idmap *idmap,
1010 struct inode *inode, const void *buf, int size,
1011 const char *eventname, enum ima_hooks func,
1012 int pcr, const char *func_data,
1013 bool buf_hash, u8 *digest, size_t digest_len)
1014 {
1015 int ret = 0;
1016 const char *audit_cause = "ENOMEM";
1017 struct ima_template_entry *entry = NULL;
1018 struct ima_iint_cache iint = {};
1019 struct ima_event_data event_data = {.iint = &iint,
1020 .filename = eventname,
1021 .buf = buf,
1022 .buf_len = size};
1023 struct ima_template_desc *template;
1024 struct ima_max_digest_data hash;
1025 struct ima_digest_data *hash_hdr = container_of(&hash.hdr,
1026 struct ima_digest_data, hdr);
1027 char digest_hash[IMA_MAX_DIGEST_SIZE];
1028 int digest_hash_len = hash_digest_size[ima_hash_algo];
1029 int violation = 0;
1030 int action = 0;
1031 struct lsm_prop prop;
1032
1033 if (digest && digest_len < digest_hash_len)
1034 return -EINVAL;
1035
1036 if (!ima_policy_flag && !digest)
1037 return -ENOENT;
1038
1039 template = ima_template_desc_buf();
1040 if (!template) {
1041 ret = -EINVAL;
1042 audit_cause = "ima_template_desc_buf";
1043 goto out;
1044 }
1045
1046 /*
1047 * Both LSM hooks and auxiliary based buffer measurements are
1048 * based on policy. To avoid code duplication, differentiate
1049 * between the LSM hooks and auxiliary buffer measurements,
1050 * retrieving the policy rule information only for the LSM hook
1051 * buffer measurements.
1052 */
1053 if (func) {
1054 security_current_getlsmprop_subj(&prop);
1055 action = ima_get_action(idmap, inode, current_cred(),
1056 &prop, 0, func, &pcr, &template,
1057 func_data, NULL);
1058 if (!(action & IMA_MEASURE) && !digest)
1059 return -ENOENT;
1060 }
1061
1062 if (!pcr)
1063 pcr = CONFIG_IMA_MEASURE_PCR_IDX;
1064
1065 iint.ima_hash = hash_hdr;
1066 iint.ima_hash->algo = ima_hash_algo;
1067 iint.ima_hash->length = hash_digest_size[ima_hash_algo];
1068
1069 ret = ima_calc_buffer_hash(buf, size, iint.ima_hash);
1070 if (ret < 0) {
1071 audit_cause = "hashing_error";
1072 goto out;
1073 }
1074
1075 if (buf_hash) {
1076 memcpy(digest_hash, hash_hdr->digest, digest_hash_len);
1077
1078 ret = ima_calc_buffer_hash(digest_hash, digest_hash_len,
1079 iint.ima_hash);
1080 if (ret < 0) {
1081 audit_cause = "hashing_error";
1082 goto out;
1083 }
1084
1085 event_data.buf = digest_hash;
1086 event_data.buf_len = digest_hash_len;
1087 }
1088
1089 if (digest)
1090 memcpy(digest, iint.ima_hash->digest, digest_hash_len);
1091
1092 if (!ima_policy_flag || (func && !(action & IMA_MEASURE)))
1093 return 1;
1094
1095 ret = ima_alloc_init_template(&event_data, &entry, template);
1096 if (ret < 0) {
1097 audit_cause = "alloc_entry";
1098 goto out;
1099 }
1100
1101 ret = ima_store_template(entry, violation, NULL, event_data.buf, pcr);
1102 if (ret < 0) {
1103 audit_cause = "store_entry";
1104 ima_free_template_entry(entry);
1105 }
1106
1107 out:
1108 if (ret < 0)
1109 integrity_audit_message(AUDIT_INTEGRITY_PCR, NULL, eventname,
1110 func_measure_str(func),
1111 audit_cause, ret, 0, ret);
1112
1113 return ret;
1114 }
1115
1116 /**
1117 * ima_kexec_cmdline - measure kexec cmdline boot args
1118 * @kernel_fd: file descriptor of the kexec kernel being loaded
1119 * @buf: pointer to buffer
1120 * @size: size of buffer
1121 *
1122 * Buffers can only be measured, not appraised.
1123 */
ima_kexec_cmdline(int kernel_fd,const void * buf,int size)1124 void ima_kexec_cmdline(int kernel_fd, const void *buf, int size)
1125 {
1126 if (!buf || !size)
1127 return;
1128
1129 CLASS(fd, f)(kernel_fd);
1130 if (fd_empty(f))
1131 return;
1132
1133 process_buffer_measurement(file_mnt_idmap(fd_file(f)), file_inode(fd_file(f)),
1134 buf, size, "kexec-cmdline", KEXEC_CMDLINE, 0,
1135 NULL, false, NULL, 0);
1136 }
1137
1138 /**
1139 * ima_measure_critical_data - measure kernel integrity critical data
1140 * @event_label: unique event label for grouping and limiting critical data
1141 * @event_name: event name for the record in the IMA measurement list
1142 * @buf: pointer to buffer data
1143 * @buf_len: length of buffer data (in bytes)
1144 * @hash: measure buffer data hash
1145 * @digest: buffer digest will be written to
1146 * @digest_len: buffer length
1147 *
1148 * Measure data critical to the integrity of the kernel into the IMA log
1149 * and extend the pcr. Examples of critical data could be various data
1150 * structures, policies, and states stored in kernel memory that can
1151 * impact the integrity of the system.
1152 *
1153 * Return: 0 if the buffer has been successfully measured, 1 if the digest
1154 * has been written to the passed location but not added to a measurement entry,
1155 * a negative value otherwise.
1156 */
ima_measure_critical_data(const char * event_label,const char * event_name,const void * buf,size_t buf_len,bool hash,u8 * digest,size_t digest_len)1157 int ima_measure_critical_data(const char *event_label,
1158 const char *event_name,
1159 const void *buf, size_t buf_len,
1160 bool hash, u8 *digest, size_t digest_len)
1161 {
1162 if (!event_name || !event_label || !buf || !buf_len)
1163 return -ENOPARAM;
1164
1165 return process_buffer_measurement(&nop_mnt_idmap, NULL, buf, buf_len,
1166 event_name, CRITICAL_DATA, 0,
1167 event_label, hash, digest,
1168 digest_len);
1169 }
1170 EXPORT_SYMBOL_GPL(ima_measure_critical_data);
1171
1172 #ifdef CONFIG_INTEGRITY_ASYMMETRIC_KEYS
1173
1174 /**
1175 * ima_kernel_module_request - Prevent crypto-pkcs1(rsa,*) requests
1176 * @kmod_name: kernel module name
1177 *
1178 * Avoid a verification loop where verifying the signature of the modprobe
1179 * binary requires executing modprobe itself. Since the modprobe iint->mutex
1180 * is already held when the signature verification is performed, a deadlock
1181 * occurs as soon as modprobe is executed within the critical region, since
1182 * the same lock cannot be taken again.
1183 *
1184 * This happens when public_key_verify_signature(), in case of RSA algorithm,
1185 * use alg_name to store internal information in order to construct an
1186 * algorithm on the fly, but crypto_larval_lookup() will try to use alg_name
1187 * in order to load a kernel module with same name.
1188 *
1189 * Since we don't have any real "crypto-pkcs1(rsa,*)" kernel modules,
1190 * we are safe to fail such module request from crypto_larval_lookup(), and
1191 * avoid the verification loop.
1192 *
1193 * Return: Zero if it is safe to load the kernel module, -EINVAL otherwise.
1194 */
ima_kernel_module_request(char * kmod_name)1195 static int ima_kernel_module_request(char *kmod_name)
1196 {
1197 if (strncmp(kmod_name, "crypto-pkcs1(rsa,", 17) == 0)
1198 return -EINVAL;
1199
1200 return 0;
1201 }
1202
1203 #endif /* CONFIG_INTEGRITY_ASYMMETRIC_KEYS */
1204
init_ima(void)1205 static int __init init_ima(void)
1206 {
1207 int error;
1208
1209 /*Note that turning IMA off is intentionally limited to kdump kernel.*/
1210 if (ima_disabled && is_kdump_kernel()) {
1211 pr_info("IMA functionality is disabled");
1212 return 0;
1213 }
1214
1215 ima_appraise_parse_cmdline();
1216 ima_init_template_list();
1217 hash_setup(CONFIG_IMA_DEFAULT_HASH);
1218 error = ima_init();
1219
1220 if (error && strcmp(hash_algo_name[ima_hash_algo],
1221 CONFIG_IMA_DEFAULT_HASH) != 0) {
1222 pr_info("Allocating %s failed, going to use default hash algorithm %s\n",
1223 hash_algo_name[ima_hash_algo], CONFIG_IMA_DEFAULT_HASH);
1224 hash_setup_done = 0;
1225 hash_setup(CONFIG_IMA_DEFAULT_HASH);
1226 error = ima_init();
1227 }
1228
1229 if (error)
1230 return error;
1231
1232 error = register_blocking_lsm_notifier(&ima_lsm_policy_notifier);
1233 if (error)
1234 pr_warn("Couldn't register LSM notifier, error %d\n", error);
1235
1236 if (!error)
1237 ima_update_policy_flags();
1238
1239 return error;
1240 }
1241
1242 static struct security_hook_list ima_hooks[] __ro_after_init = {
1243 LSM_HOOK_INIT(bprm_check_security, ima_bprm_check),
1244 LSM_HOOK_INIT(bprm_creds_for_exec, ima_bprm_creds_for_exec),
1245 LSM_HOOK_INIT(file_post_open, ima_file_check),
1246 LSM_HOOK_INIT(inode_post_create_tmpfile, ima_post_create_tmpfile),
1247 LSM_HOOK_INIT(file_release, ima_file_free),
1248 LSM_HOOK_INIT(mmap_file, ima_file_mmap),
1249 LSM_HOOK_INIT(file_mprotect, ima_file_mprotect),
1250 LSM_HOOK_INIT(kernel_load_data, ima_load_data),
1251 LSM_HOOK_INIT(kernel_post_load_data, ima_post_load_data),
1252 LSM_HOOK_INIT(kernel_read_file, ima_read_file),
1253 LSM_HOOK_INIT(kernel_post_read_file, ima_post_read_file),
1254 LSM_HOOK_INIT(path_post_mknod, ima_post_path_mknod),
1255 #ifdef CONFIG_IMA_MEASURE_ASYMMETRIC_KEYS
1256 LSM_HOOK_INIT(key_post_create_or_update, ima_post_key_create_or_update),
1257 #endif
1258 #ifdef CONFIG_INTEGRITY_ASYMMETRIC_KEYS
1259 LSM_HOOK_INIT(kernel_module_request, ima_kernel_module_request),
1260 #endif
1261 LSM_HOOK_INIT(inode_free_security_rcu, ima_inode_free_rcu),
1262 };
1263
1264 static const struct lsm_id ima_lsmid = {
1265 .name = "ima",
1266 .id = LSM_ID_IMA,
1267 };
1268
init_ima_lsm(void)1269 static int __init init_ima_lsm(void)
1270 {
1271 ima_iintcache_init();
1272 security_add_hooks(ima_hooks, ARRAY_SIZE(ima_hooks), &ima_lsmid);
1273 init_ima_appraise_lsm(&ima_lsmid);
1274 return 0;
1275 }
1276
1277 struct lsm_blob_sizes ima_blob_sizes __ro_after_init = {
1278 .lbs_inode = sizeof(struct ima_iint_cache *),
1279 };
1280
1281 DEFINE_LSM(ima) = {
1282 .name = "ima",
1283 .init = init_ima_lsm,
1284 .order = LSM_ORDER_LAST,
1285 .blobs = &ima_blob_sizes,
1286 };
1287
1288 late_initcall(init_ima); /* Start IMA after the TPM is available */
1289