1 // SPDX-License-Identifier: GPL-2.0-only
3 * Integrity Measurement Architecture
5 * Copyright (C) 2005,2006,2007,2008 IBM Corporation
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>
14 * implements the IMA hooks: ima_bprm_check, ima_file_mmap,
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/iversion.h>
32 #ifdef CONFIG_IMA_APPRAISE
33 int ima_appraise = IMA_APPRAISE_ENFORCE;
38 int ima_hash_algo = HASH_ALGO_SHA1;
39 static int hash_setup_done;
41 static struct notifier_block ima_lsm_policy_notifier = {
42 .notifier_call = ima_lsm_policy_change,
45 static int __init hash_setup(char *str)
47 struct ima_template_desc *template_desc = ima_template_desc_current();
53 if (strcmp(template_desc->name, IMA_TEMPLATE_IMA_NAME) == 0) {
54 if (strncmp(str, "sha1", 4) == 0) {
55 ima_hash_algo = HASH_ALGO_SHA1;
56 } else if (strncmp(str, "md5", 3) == 0) {
57 ima_hash_algo = HASH_ALGO_MD5;
59 pr_err("invalid hash algorithm \"%s\" for template \"%s\"",
60 str, IMA_TEMPLATE_IMA_NAME);
66 i = match_string(hash_algo_name, HASH_ALGO__LAST, str);
68 pr_err("invalid hash algorithm \"%s\"", str);
77 __setup("ima_hash=", hash_setup);
79 /* Prevent mmap'ing a file execute that is already mmap'ed write */
80 static int mmap_violation_check(enum ima_hooks func, struct file *file,
81 char **pathbuf, const char **pathname,
87 if ((func == MMAP_CHECK) && mapping_writably_mapped(file->f_mapping)) {
89 inode = file_inode(file);
91 if (!*pathbuf) /* ima_rdwr_violation possibly pre-fetched */
92 *pathname = ima_d_path(&file->f_path, pathbuf,
94 integrity_audit_msg(AUDIT_INTEGRITY_DATA, inode, *pathname,
95 "mmap_file", "mmapped_writers", rc, 0);
101 * ima_rdwr_violation_check
103 * Only invalidate the PCR for measured files:
104 * - Opening a file for write when already open for read,
105 * results in a time of measure, time of use (ToMToU) error.
106 * - Opening a file for read when already open for write,
107 * could result in a file measurement error.
110 static void ima_rdwr_violation_check(struct file *file,
111 struct integrity_iint_cache *iint,
114 const char **pathname,
117 struct inode *inode = file_inode(file);
118 fmode_t mode = file->f_mode;
119 bool send_tomtou = false, send_writers = false;
121 if (mode & FMODE_WRITE) {
122 if (atomic_read(&inode->i_readcount) && IS_IMA(inode)) {
124 iint = integrity_iint_find(inode);
125 /* IMA_MEASURE is set from reader side */
126 if (iint && test_bit(IMA_MUST_MEASURE,
127 &iint->atomic_flags))
132 set_bit(IMA_MUST_MEASURE, &iint->atomic_flags);
133 if (inode_is_open_for_write(inode) && must_measure)
137 if (!send_tomtou && !send_writers)
140 *pathname = ima_d_path(&file->f_path, pathbuf, filename);
143 ima_add_violation(file, *pathname, iint,
144 "invalid_pcr", "ToMToU");
146 ima_add_violation(file, *pathname, iint,
147 "invalid_pcr", "open_writers");
150 static void ima_check_last_writer(struct integrity_iint_cache *iint,
151 struct inode *inode, struct file *file)
153 fmode_t mode = file->f_mode;
156 if (!(mode & FMODE_WRITE))
159 mutex_lock(&iint->mutex);
160 if (atomic_read(&inode->i_writecount) == 1) {
161 update = test_and_clear_bit(IMA_UPDATE_XATTR,
162 &iint->atomic_flags);
163 if (!IS_I_VERSION(inode) ||
164 !inode_eq_iversion(inode, iint->version) ||
165 (iint->flags & IMA_NEW_FILE)) {
166 iint->flags &= ~(IMA_DONE_MASK | IMA_NEW_FILE);
167 iint->measured_pcrs = 0;
169 ima_update_xattr(iint, file);
172 mutex_unlock(&iint->mutex);
176 * ima_file_free - called on __fput()
177 * @file: pointer to file structure being freed
179 * Flag files that changed, based on i_version
181 void ima_file_free(struct file *file)
183 struct inode *inode = file_inode(file);
184 struct integrity_iint_cache *iint;
186 if (!ima_policy_flag || !S_ISREG(inode->i_mode))
189 iint = integrity_iint_find(inode);
193 ima_check_last_writer(iint, inode, file);
196 static int process_measurement(struct file *file, const struct cred *cred,
197 u32 secid, char *buf, loff_t size, int mask,
200 struct inode *inode = file_inode(file);
201 struct integrity_iint_cache *iint = NULL;
202 struct ima_template_desc *template_desc = NULL;
203 char *pathbuf = NULL;
204 char filename[NAME_MAX];
205 const char *pathname = NULL;
206 int rc = 0, action, must_appraise = 0;
207 int pcr = CONFIG_IMA_MEASURE_PCR_IDX;
208 struct evm_ima_xattr_data *xattr_value = NULL;
209 struct modsig *modsig = NULL;
211 bool violation_check;
212 enum hash_algo hash_algo;
214 if (!ima_policy_flag || !S_ISREG(inode->i_mode))
217 /* Return an IMA_MEASURE, IMA_APPRAISE, IMA_AUDIT action
218 * bitmask based on the appraise/audit/measurement policy.
219 * Included is the appraise submask.
221 action = ima_get_action(inode, cred, secid, mask, func, &pcr,
222 &template_desc, NULL);
223 violation_check = ((func == FILE_CHECK || func == MMAP_CHECK) &&
224 (ima_policy_flag & IMA_MEASURE));
225 if (!action && !violation_check)
228 must_appraise = action & IMA_APPRAISE;
230 /* Is the appraise rule hook specific? */
231 if (action & IMA_FILE_APPRAISE)
237 iint = integrity_inode_get(inode);
242 if (!rc && violation_check)
243 ima_rdwr_violation_check(file, iint, action & IMA_MEASURE,
244 &pathbuf, &pathname, filename);
253 mutex_lock(&iint->mutex);
255 if (test_and_clear_bit(IMA_CHANGE_ATTR, &iint->atomic_flags))
256 /* reset appraisal flags if ima_inode_post_setattr was called */
257 iint->flags &= ~(IMA_APPRAISE | IMA_APPRAISED |
258 IMA_APPRAISE_SUBMASK | IMA_APPRAISED_SUBMASK |
262 * Re-evaulate the file if either the xattr has changed or the
263 * kernel has no way of detecting file change on the filesystem.
264 * (Limited to privileged mounted filesystems.)
266 if (test_and_clear_bit(IMA_CHANGE_XATTR, &iint->atomic_flags) ||
267 ((inode->i_sb->s_iflags & SB_I_IMA_UNVERIFIABLE_SIGNATURE) &&
268 !(inode->i_sb->s_iflags & SB_I_UNTRUSTED_MOUNTER) &&
269 !(action & IMA_FAIL_UNVERIFIABLE_SIGS))) {
270 iint->flags &= ~IMA_DONE_MASK;
271 iint->measured_pcrs = 0;
274 /* Determine if already appraised/measured based on bitmask
275 * (IMA_MEASURE, IMA_MEASURED, IMA_XXXX_APPRAISE, IMA_XXXX_APPRAISED,
276 * IMA_AUDIT, IMA_AUDITED)
278 iint->flags |= action;
279 action &= IMA_DO_MASK;
280 action &= ~((iint->flags & (IMA_DONE_MASK ^ IMA_MEASURED)) >> 1);
282 /* If target pcr is already measured, unset IMA_MEASURE action */
283 if ((action & IMA_MEASURE) && (iint->measured_pcrs & (0x1 << pcr)))
284 action ^= IMA_MEASURE;
286 /* HASH sets the digital signature and update flags, nothing else */
287 if ((action & IMA_HASH) &&
288 !(test_bit(IMA_DIGSIG, &iint->atomic_flags))) {
289 xattr_len = ima_read_xattr(file_dentry(file), &xattr_value);
290 if ((xattr_value && xattr_len > 2) &&
291 (xattr_value->type == EVM_IMA_XATTR_DIGSIG))
292 set_bit(IMA_DIGSIG, &iint->atomic_flags);
293 iint->flags |= IMA_HASHED;
295 set_bit(IMA_UPDATE_XATTR, &iint->atomic_flags);
298 /* Nothing to do, just return existing appraised status */
301 rc = mmap_violation_check(func, file, &pathbuf,
302 &pathname, filename);
304 rc = ima_get_cache_status(iint, func);
309 if ((action & IMA_APPRAISE_SUBMASK) ||
310 strcmp(template_desc->name, IMA_TEMPLATE_IMA_NAME) != 0) {
311 /* read 'security.ima' */
312 xattr_len = ima_read_xattr(file_dentry(file), &xattr_value);
315 * Read the appended modsig if allowed by the policy, and allow
316 * an additional measurement list entry, if needed, based on the
317 * template format and whether the file was already measured.
319 if (iint->flags & IMA_MODSIG_ALLOWED) {
320 rc = ima_read_modsig(func, buf, size, &modsig);
322 if (!rc && ima_template_has_modsig(template_desc) &&
323 iint->flags & IMA_MEASURED)
324 action |= IMA_MEASURE;
328 hash_algo = ima_get_hash_algo(xattr_value, xattr_len);
330 rc = ima_collect_measurement(iint, file, buf, size, hash_algo, modsig);
331 if (rc != 0 && rc != -EBADF && rc != -EINVAL)
334 if (!pathbuf) /* ima_rdwr_violation possibly pre-fetched */
335 pathname = ima_d_path(&file->f_path, &pathbuf, filename);
337 if (action & IMA_MEASURE)
338 ima_store_measurement(iint, file, pathname,
339 xattr_value, xattr_len, modsig, pcr,
341 if (rc == 0 && (action & IMA_APPRAISE_SUBMASK)) {
342 rc = ima_check_blacklist(iint, modsig, pcr);
345 rc = ima_appraise_measurement(func, iint, file,
346 pathname, xattr_value,
351 rc = mmap_violation_check(func, file, &pathbuf,
352 &pathname, filename);
354 if (action & IMA_AUDIT)
355 ima_audit_measurement(iint, pathname);
357 if ((file->f_flags & O_DIRECT) && (iint->flags & IMA_PERMIT_DIRECTIO))
360 if ((mask & MAY_WRITE) && test_bit(IMA_DIGSIG, &iint->atomic_flags) &&
361 !(iint->flags & IMA_NEW_FILE))
363 mutex_unlock(&iint->mutex);
365 ima_free_modsig(modsig);
370 if (rc && (ima_appraise & IMA_APPRAISE_ENFORCE))
372 if (file->f_mode & FMODE_WRITE)
373 set_bit(IMA_UPDATE_XATTR, &iint->atomic_flags);
379 * ima_file_mmap - based on policy, collect/store measurement.
380 * @file: pointer to the file to be measured (May be NULL)
381 * @prot: contains the protection that will be applied by the kernel.
383 * Measure files being mmapped executable based on the ima_must_measure()
386 * On success return 0. On integrity appraisal error, assuming the file
387 * is in policy and IMA-appraisal is in enforcing mode, return -EACCES.
389 int ima_file_mmap(struct file *file, unsigned long prot)
393 if (file && (prot & PROT_EXEC)) {
394 security_task_getsecid(current, &secid);
395 return process_measurement(file, current_cred(), secid, NULL,
396 0, MAY_EXEC, MMAP_CHECK);
403 * ima_file_mprotect - based on policy, limit mprotect change
404 * @prot: contains the protection that will be applied by the kernel.
406 * Files can be mmap'ed read/write and later changed to execute to circumvent
407 * IMA's mmap appraisal policy rules. Due to locking issues (mmap semaphore
408 * would be taken before i_mutex), files can not be measured or appraised at
409 * this point. Eliminate this integrity gap by denying the mprotect
410 * PROT_EXECUTE change, if an mmap appraise policy rule exists.
412 * On mprotect change success, return 0. On failure, return -EACESS.
414 int ima_file_mprotect(struct vm_area_struct *vma, unsigned long prot)
416 struct ima_template_desc *template = NULL;
417 struct file *file = vma->vm_file;
418 char filename[NAME_MAX];
419 char *pathbuf = NULL;
420 const char *pathname = NULL;
427 /* Is mprotect making an mmap'ed file executable? */
428 if (!(ima_policy_flag & IMA_APPRAISE) || !vma->vm_file ||
429 !(prot & PROT_EXEC) || (vma->vm_flags & VM_EXEC))
432 security_task_getsecid(current, &secid);
433 inode = file_inode(vma->vm_file);
434 action = ima_get_action(inode, current_cred(), secid, MAY_EXEC,
435 MMAP_CHECK, &pcr, &template, 0);
437 /* Is the mmap'ed file in policy? */
438 if (!(action & (IMA_MEASURE | IMA_APPRAISE_SUBMASK)))
441 if (action & IMA_APPRAISE_SUBMASK)
445 pathname = ima_d_path(&file->f_path, &pathbuf, filename);
446 integrity_audit_msg(AUDIT_INTEGRITY_DATA, inode, pathname,
447 "collect_data", "failed-mprotect", result, 0);
455 * ima_bprm_check - based on policy, collect/store measurement.
456 * @bprm: contains the linux_binprm structure
458 * The OS protects against an executable file, already open for write,
459 * from being executed in deny_write_access() and an executable file,
460 * already open for execute, from being modified in get_write_access().
461 * So we can be certain that what we verify and measure here is actually
462 * what is being executed.
464 * On success return 0. On integrity appraisal error, assuming the file
465 * is in policy and IMA-appraisal is in enforcing mode, return -EACCES.
467 int ima_bprm_check(struct linux_binprm *bprm)
472 security_task_getsecid(current, &secid);
473 ret = process_measurement(bprm->file, current_cred(), secid, NULL, 0,
474 MAY_EXEC, BPRM_CHECK);
478 security_cred_getsecid(bprm->cred, &secid);
479 return process_measurement(bprm->file, bprm->cred, secid, NULL, 0,
480 MAY_EXEC, CREDS_CHECK);
484 * ima_path_check - based on policy, collect/store measurement.
485 * @file: pointer to the file to be measured
486 * @mask: contains MAY_READ, MAY_WRITE, MAY_EXEC or MAY_APPEND
488 * Measure files based on the ima_must_measure() policy decision.
490 * On success return 0. On integrity appraisal error, assuming the file
491 * is in policy and IMA-appraisal is in enforcing mode, return -EACCES.
493 int ima_file_check(struct file *file, int mask)
497 security_task_getsecid(current, &secid);
498 return process_measurement(file, current_cred(), secid, NULL, 0,
499 mask & (MAY_READ | MAY_WRITE | MAY_EXEC |
500 MAY_APPEND), FILE_CHECK);
502 EXPORT_SYMBOL_GPL(ima_file_check);
504 static int __ima_inode_hash(struct inode *inode, char *buf, size_t buf_size)
506 struct integrity_iint_cache *iint;
509 if (!ima_policy_flag)
512 iint = integrity_iint_find(inode);
516 mutex_lock(&iint->mutex);
519 * ima_file_hash can be called when ima_collect_measurement has still
520 * not been called, we might not always have a hash.
522 if (!iint->ima_hash) {
523 mutex_unlock(&iint->mutex);
530 copied_size = min_t(size_t, iint->ima_hash->length, buf_size);
531 memcpy(buf, iint->ima_hash->digest, copied_size);
533 hash_algo = iint->ima_hash->algo;
534 mutex_unlock(&iint->mutex);
540 * ima_file_hash - return the stored measurement if a file has been hashed and
541 * is in the iint cache.
542 * @file: pointer to the file
543 * @buf: buffer in which to store the hash
544 * @buf_size: length of the buffer
546 * On success, return the hash algorithm (as defined in the enum hash_algo).
547 * If buf is not NULL, this function also outputs the hash into buf.
548 * If the hash is larger than buf_size, then only buf_size bytes will be copied.
549 * It generally just makes sense to pass a buffer capable of holding the largest
550 * possible hash: IMA_MAX_DIGEST_SIZE.
551 * The file hash returned is based on the entire file, including the appended
554 * If IMA is disabled or if no measurement is available, return -EOPNOTSUPP.
555 * If the parameters are incorrect, return -EINVAL.
557 int ima_file_hash(struct file *file, char *buf, size_t buf_size)
562 return __ima_inode_hash(file_inode(file), buf, buf_size);
564 EXPORT_SYMBOL_GPL(ima_file_hash);
567 * ima_inode_hash - return the stored measurement if the inode has been hashed
568 * and is in the iint cache.
569 * @inode: pointer to the inode
570 * @buf: buffer in which to store the hash
571 * @buf_size: length of the buffer
573 * On success, return the hash algorithm (as defined in the enum hash_algo).
574 * If buf is not NULL, this function also outputs the hash into buf.
575 * If the hash is larger than buf_size, then only buf_size bytes will be copied.
576 * It generally just makes sense to pass a buffer capable of holding the largest
577 * possible hash: IMA_MAX_DIGEST_SIZE.
578 * The hash returned is based on the entire contents, including the appended
581 * If IMA is disabled or if no measurement is available, return -EOPNOTSUPP.
582 * If the parameters are incorrect, return -EINVAL.
584 int ima_inode_hash(struct inode *inode, char *buf, size_t buf_size)
589 return __ima_inode_hash(inode, buf, buf_size);
591 EXPORT_SYMBOL_GPL(ima_inode_hash);
594 * ima_post_create_tmpfile - mark newly created tmpfile as new
595 * @file : newly created tmpfile
597 * No measuring, appraising or auditing of newly created tmpfiles is needed.
598 * Skip calling process_measurement(), but indicate which newly, created
599 * tmpfiles are in policy.
601 void ima_post_create_tmpfile(struct inode *inode)
603 struct integrity_iint_cache *iint;
606 must_appraise = ima_must_appraise(inode, MAY_ACCESS, FILE_CHECK);
610 /* Nothing to do if we can't allocate memory */
611 iint = integrity_inode_get(inode);
615 /* needed for writing the security xattrs */
616 set_bit(IMA_UPDATE_XATTR, &iint->atomic_flags);
617 iint->ima_file_status = INTEGRITY_PASS;
621 * ima_post_path_mknod - mark as a new inode
622 * @dentry: newly created dentry
624 * Mark files created via the mknodat syscall as new, so that the
625 * file data can be written later.
627 void ima_post_path_mknod(struct dentry *dentry)
629 struct integrity_iint_cache *iint;
630 struct inode *inode = dentry->d_inode;
633 must_appraise = ima_must_appraise(inode, MAY_ACCESS, FILE_CHECK);
637 /* Nothing to do if we can't allocate memory */
638 iint = integrity_inode_get(inode);
642 /* needed for re-opening empty files */
643 iint->flags |= IMA_NEW_FILE;
647 * ima_read_file - pre-measure/appraise hook decision based on policy
648 * @file: pointer to the file to be measured/appraised/audit
649 * @read_id: caller identifier
650 * @contents: whether a subsequent call will be made to ima_post_read_file()
652 * Permit reading a file based on policy. The policy rules are written
653 * in terms of the policy identifier. Appraising the integrity of
654 * a file requires a file descriptor.
656 * For permission return 0, otherwise return -EACCES.
658 int ima_read_file(struct file *file, enum kernel_read_file_id read_id,
665 * Do devices using pre-allocated memory run the risk of the
666 * firmware being accessible to the device prior to the completion
667 * of IMA's signature verification any more than when using two
668 * buffers? It may be desirable to include the buffer address
669 * in this API and walk all the dma_map_single() mappings to check.
673 * There will be a call made to ima_post_read_file() with
674 * a filled buffer, so we don't need to perform an extra
680 /* Read entire file for all partial reads. */
681 func = read_idmap[read_id] ?: FILE_CHECK;
682 security_task_getsecid(current, &secid);
683 return process_measurement(file, current_cred(), secid, NULL,
687 const int read_idmap[READING_MAX_ID] = {
688 [READING_FIRMWARE] = FIRMWARE_CHECK,
689 [READING_MODULE] = MODULE_CHECK,
690 [READING_KEXEC_IMAGE] = KEXEC_KERNEL_CHECK,
691 [READING_KEXEC_INITRAMFS] = KEXEC_INITRAMFS_CHECK,
692 [READING_POLICY] = POLICY_CHECK
696 * ima_post_read_file - in memory collect/appraise/audit measurement
697 * @file: pointer to the file to be measured/appraised/audit
698 * @buf: pointer to in memory file contents
699 * @size: size of in memory file contents
700 * @read_id: caller identifier
702 * Measure/appraise/audit in memory file based on policy. Policy rules
703 * are written in terms of a policy identifier.
705 * On success return 0. On integrity appraisal error, assuming the file
706 * is in policy and IMA-appraisal is in enforcing mode, return -EACCES.
708 int ima_post_read_file(struct file *file, void *buf, loff_t size,
709 enum kernel_read_file_id read_id)
714 /* permit signed certs */
715 if (!file && read_id == READING_X509_CERTIFICATE)
718 if (!file || !buf || size == 0) { /* should never happen */
719 if (ima_appraise & IMA_APPRAISE_ENFORCE)
724 func = read_idmap[read_id] ?: FILE_CHECK;
725 security_task_getsecid(current, &secid);
726 return process_measurement(file, current_cred(), secid, buf, size,
731 * ima_load_data - appraise decision based on policy
732 * @id: kernel load data caller identifier
733 * @contents: whether the full contents will be available in a later
734 * call to ima_post_load_data().
736 * Callers of this LSM hook can not measure, appraise, or audit the
737 * data provided by userspace. Enforce policy rules requring a file
738 * signature (eg. kexec'ed kernel image).
740 * For permission return 0, otherwise return -EACCES.
742 int ima_load_data(enum kernel_load_data_id id, bool contents)
744 bool ima_enforce, sig_enforce;
747 (ima_appraise & IMA_APPRAISE_ENFORCE) == IMA_APPRAISE_ENFORCE;
750 case LOADING_KEXEC_IMAGE:
751 if (IS_ENABLED(CONFIG_KEXEC_SIG)
752 && arch_ima_get_secureboot()) {
753 pr_err("impossible to appraise a kernel image without a file descriptor; try using kexec_file_load syscall.\n");
757 if (ima_enforce && (ima_appraise & IMA_APPRAISE_KEXEC)) {
758 pr_err("impossible to appraise a kernel image without a file descriptor; try using kexec_file_load syscall.\n");
759 return -EACCES; /* INTEGRITY_UNKNOWN */
762 case LOADING_FIRMWARE:
763 if (ima_enforce && (ima_appraise & IMA_APPRAISE_FIRMWARE) && !contents) {
764 pr_err("Prevent firmware sysfs fallback loading.\n");
765 return -EACCES; /* INTEGRITY_UNKNOWN */
769 sig_enforce = is_module_sig_enforced();
771 if (ima_enforce && (!sig_enforce
772 && (ima_appraise & IMA_APPRAISE_MODULES))) {
773 pr_err("impossible to appraise a module without a file descriptor. sig_enforce kernel parameter might help\n");
774 return -EACCES; /* INTEGRITY_UNKNOWN */
783 * ima_post_load_data - appraise decision based on policy
784 * @buf: pointer to in memory file contents
785 * @size: size of in memory file contents
786 * @id: kernel load data caller identifier
787 * @description: @id-specific description of contents
789 * Measure/appraise/audit in memory buffer based on policy. Policy rules
790 * are written in terms of a policy identifier.
792 * On success return 0. On integrity appraisal error, assuming the file
793 * is in policy and IMA-appraisal is in enforcing mode, return -EACCES.
795 int ima_post_load_data(char *buf, loff_t size,
796 enum kernel_load_data_id load_id,
799 if (load_id == LOADING_FIRMWARE) {
800 if ((ima_appraise & IMA_APPRAISE_FIRMWARE) &&
801 (ima_appraise & IMA_APPRAISE_ENFORCE)) {
802 pr_err("Prevent firmware loading_store.\n");
803 return -EACCES; /* INTEGRITY_UNKNOWN */
812 * process_buffer_measurement - Measure the buffer to ima log.
813 * @inode: inode associated with the object being measured (NULL for KEY_CHECK)
814 * @buf: pointer to the buffer that needs to be added to the log.
815 * @size: size of buffer(in bytes).
816 * @eventname: event name to be used for the buffer entry.
818 * @pcr: pcr to extend the measurement
819 * @keyring: keyring name to determine the action to be performed
821 * Based on policy, the buffer is measured into the ima log.
823 void process_buffer_measurement(struct inode *inode, const void *buf, int size,
824 const char *eventname, enum ima_hooks func,
825 int pcr, const char *keyring)
828 const char *audit_cause = "ENOMEM";
829 struct ima_template_entry *entry = NULL;
830 struct integrity_iint_cache iint = {};
831 struct ima_event_data event_data = {.iint = &iint,
832 .filename = eventname,
835 struct ima_template_desc *template;
837 struct ima_digest_data hdr;
838 char digest[IMA_MAX_DIGEST_SIZE];
844 if (!ima_policy_flag)
847 template = ima_template_desc_buf();
850 audit_cause = "ima_template_desc_buf";
855 * Both LSM hooks and auxilary based buffer measurements are
856 * based on policy. To avoid code duplication, differentiate
857 * between the LSM hooks and auxilary buffer measurements,
858 * retrieving the policy rule information only for the LSM hook
859 * buffer measurements.
862 security_task_getsecid(current, &secid);
863 action = ima_get_action(inode, current_cred(), secid, 0, func,
864 &pcr, &template, keyring);
865 if (!(action & IMA_MEASURE))
870 pcr = CONFIG_IMA_MEASURE_PCR_IDX;
872 iint.ima_hash = &hash.hdr;
873 iint.ima_hash->algo = ima_hash_algo;
874 iint.ima_hash->length = hash_digest_size[ima_hash_algo];
876 ret = ima_calc_buffer_hash(buf, size, iint.ima_hash);
878 audit_cause = "hashing_error";
882 ret = ima_alloc_init_template(&event_data, &entry, template);
884 audit_cause = "alloc_entry";
888 ret = ima_store_template(entry, violation, NULL, buf, pcr);
890 audit_cause = "store_entry";
891 ima_free_template_entry(entry);
896 integrity_audit_message(AUDIT_INTEGRITY_PCR, NULL, eventname,
897 func_measure_str(func),
898 audit_cause, ret, 0, ret);
904 * ima_kexec_cmdline - measure kexec cmdline boot args
905 * @kernel_fd: file descriptor of the kexec kernel being loaded
906 * @buf: pointer to buffer
907 * @size: size of buffer
909 * Buffers can only be measured, not appraised.
911 void ima_kexec_cmdline(int kernel_fd, const void *buf, int size)
918 f = fdget(kernel_fd);
922 process_buffer_measurement(file_inode(f.file), buf, size,
923 "kexec-cmdline", KEXEC_CMDLINE, 0, NULL);
927 static int __init init_ima(void)
931 ima_appraise_parse_cmdline();
932 ima_init_template_list();
933 hash_setup(CONFIG_IMA_DEFAULT_HASH);
936 if (error && strcmp(hash_algo_name[ima_hash_algo],
937 CONFIG_IMA_DEFAULT_HASH) != 0) {
938 pr_info("Allocating %s failed, going to use default hash algorithm %s\n",
939 hash_algo_name[ima_hash_algo], CONFIG_IMA_DEFAULT_HASH);
941 hash_setup(CONFIG_IMA_DEFAULT_HASH);
948 error = register_blocking_lsm_notifier(&ima_lsm_policy_notifier);
950 pr_warn("Couldn't register LSM notifier, error %d\n", error);
953 ima_update_policy_flag();
958 late_initcall(init_ima); /* Start IMA after the TPM is available */