1 // SPDX-License-Identifier: GPL-2.0-only
3 * Copyright (C) 2005-2010 IBM Corporation
6 * Mimi Zohar <zohar@us.ibm.com>
7 * Kylene Hall <kjhall@us.ibm.com>
10 * implements evm_inode_setxattr, evm_inode_post_setxattr,
11 * evm_inode_removexattr, evm_verifyxattr, and evm_inode_set_acl.
14 #define pr_fmt(fmt) "EVM: "fmt
16 #include <linux/init.h>
17 #include <linux/audit.h>
18 #include <linux/xattr.h>
19 #include <linux/integrity.h>
20 #include <linux/evm.h>
21 #include <linux/magic.h>
22 #include <linux/posix_acl_xattr.h>
23 #include <linux/lsm_hooks.h>
25 #include <crypto/hash.h>
26 #include <crypto/hash_info.h>
27 #include <crypto/utils.h>
32 static const char * const integrity_status_msg[] = {
33 "pass", "pass_immutable", "fail", "fail_immutable", "no_label",
34 "no_xattrs", "unknown"
38 static struct xattr_list evm_config_default_xattrnames[] = {
40 .name = XATTR_NAME_SELINUX,
41 .enabled = IS_ENABLED(CONFIG_SECURITY_SELINUX)
44 .name = XATTR_NAME_SMACK,
45 .enabled = IS_ENABLED(CONFIG_SECURITY_SMACK)
48 .name = XATTR_NAME_SMACKEXEC,
49 .enabled = IS_ENABLED(CONFIG_EVM_EXTRA_SMACK_XATTRS)
52 .name = XATTR_NAME_SMACKTRANSMUTE,
53 .enabled = IS_ENABLED(CONFIG_EVM_EXTRA_SMACK_XATTRS)
56 .name = XATTR_NAME_SMACKMMAP,
57 .enabled = IS_ENABLED(CONFIG_EVM_EXTRA_SMACK_XATTRS)
60 .name = XATTR_NAME_APPARMOR,
61 .enabled = IS_ENABLED(CONFIG_SECURITY_APPARMOR)
64 .name = XATTR_NAME_IMA,
65 .enabled = IS_ENABLED(CONFIG_IMA_APPRAISE)
68 .name = XATTR_NAME_CAPS,
73 LIST_HEAD(evm_config_xattrnames);
75 static int evm_fixmode __ro_after_init;
76 static int __init evm_set_fixmode(char *str)
78 if (strncmp(str, "fix", 3) == 0)
81 pr_err("invalid \"%s\" mode", str);
85 __setup("evm=", evm_set_fixmode);
87 static void __init evm_init_config(void)
91 xattrs = ARRAY_SIZE(evm_config_default_xattrnames);
93 pr_info("Initialising EVM extended attributes:\n");
94 for (i = 0; i < xattrs; i++) {
95 pr_info("%s%s\n", evm_config_default_xattrnames[i].name,
96 !evm_config_default_xattrnames[i].enabled ?
98 list_add_tail(&evm_config_default_xattrnames[i].list,
99 &evm_config_xattrnames);
102 #ifdef CONFIG_EVM_ATTR_FSUUID
103 evm_hmac_attrs |= EVM_ATTR_FSUUID;
105 pr_info("HMAC attrs: 0x%x\n", evm_hmac_attrs);
108 static bool evm_key_loaded(void)
110 return (bool)(evm_initialized & EVM_KEY_MASK);
114 * This function determines whether or not it is safe to ignore verification
115 * errors, based on the ability of EVM to calculate HMACs. If the HMAC key
116 * is not loaded, and it cannot be loaded in the future due to the
117 * EVM_SETUP_COMPLETE initialization flag, allowing an operation despite the
118 * attrs/xattrs being found invalid will not make them valid.
120 static bool evm_hmac_disabled(void)
122 if (evm_initialized & EVM_INIT_HMAC)
125 if (!(evm_initialized & EVM_SETUP_COMPLETE))
131 static int evm_find_protected_xattrs(struct dentry *dentry)
133 struct inode *inode = d_backing_inode(dentry);
134 struct xattr_list *xattr;
138 if (!(inode->i_opflags & IOP_XATTR))
141 list_for_each_entry_lockless(xattr, &evm_config_xattrnames, list) {
142 error = __vfs_getxattr(dentry, inode, xattr->name, NULL, 0);
144 if (error == -ENODATA)
154 static int is_unsupported_fs(struct dentry *dentry)
156 struct inode *inode = d_backing_inode(dentry);
158 if (inode->i_sb->s_iflags & SB_I_EVM_UNSUPPORTED) {
159 pr_info_once("%s not supported\n", inode->i_sb->s_type->name);
166 * evm_verify_hmac - calculate and compare the HMAC with the EVM xattr
168 * Compute the HMAC on the dentry's protected set of extended attributes
169 * and compare it against the stored security.evm xattr.
172 * - use the previoulsy retrieved xattr value and length to calculate the
174 * - cache the verification result in the iint, when available.
176 * Returns integrity status
178 static enum integrity_status evm_verify_hmac(struct dentry *dentry,
179 const char *xattr_name,
181 size_t xattr_value_len,
182 struct integrity_iint_cache *iint)
184 struct evm_ima_xattr_data *xattr_data = NULL;
185 struct signature_v2_hdr *hdr;
186 enum integrity_status evm_status = INTEGRITY_PASS;
187 struct evm_digest digest;
189 int rc, xattr_len, evm_immutable = 0;
191 if (iint && (iint->evm_status == INTEGRITY_PASS ||
192 iint->evm_status == INTEGRITY_PASS_IMMUTABLE))
193 return iint->evm_status;
195 if (is_unsupported_fs(dentry))
196 return INTEGRITY_UNKNOWN;
198 /* if status is not PASS, try to check again - against -ENOMEM */
200 /* first need to know the sig type */
201 rc = vfs_getxattr_alloc(&nop_mnt_idmap, dentry, XATTR_NAME_EVM,
202 (char **)&xattr_data, 0, GFP_NOFS);
204 evm_status = INTEGRITY_FAIL;
205 if (rc == -ENODATA) {
206 rc = evm_find_protected_xattrs(dentry);
208 evm_status = INTEGRITY_NOLABEL;
210 evm_status = INTEGRITY_NOXATTRS; /* new file */
211 } else if (rc == -EOPNOTSUPP) {
212 evm_status = INTEGRITY_UNKNOWN;
219 /* check value type */
220 switch (xattr_data->type) {
222 if (xattr_len != sizeof(struct evm_xattr)) {
223 evm_status = INTEGRITY_FAIL;
227 digest.hdr.algo = HASH_ALGO_SHA1;
228 rc = evm_calc_hmac(dentry, xattr_name, xattr_value,
229 xattr_value_len, &digest);
232 rc = crypto_memneq(xattr_data->data, digest.digest,
237 case EVM_XATTR_PORTABLE_DIGSIG:
240 case EVM_IMA_XATTR_DIGSIG:
241 /* accept xattr with non-empty signature field */
242 if (xattr_len <= sizeof(struct signature_v2_hdr)) {
243 evm_status = INTEGRITY_FAIL;
247 hdr = (struct signature_v2_hdr *)xattr_data;
248 digest.hdr.algo = hdr->hash_algo;
249 rc = evm_calc_hash(dentry, xattr_name, xattr_value,
250 xattr_value_len, xattr_data->type, &digest);
253 rc = integrity_digsig_verify(INTEGRITY_KEYRING_EVM,
254 (const char *)xattr_data, xattr_len,
255 digest.digest, digest.hdr.length);
257 inode = d_backing_inode(dentry);
259 if (xattr_data->type == EVM_XATTR_PORTABLE_DIGSIG) {
261 iint->flags |= EVM_IMMUTABLE_DIGSIG;
262 evm_status = INTEGRITY_PASS_IMMUTABLE;
263 } else if (!IS_RDONLY(inode) &&
264 !(inode->i_sb->s_readonly_remount) &&
265 !IS_IMMUTABLE(inode)) {
266 evm_update_evmxattr(dentry, xattr_name,
279 evm_status = INTEGRITY_NOXATTRS;
280 else if (evm_immutable)
281 evm_status = INTEGRITY_FAIL_IMMUTABLE;
283 evm_status = INTEGRITY_FAIL;
285 pr_debug("digest: (%d) [%*phN]\n", digest.hdr.length, digest.hdr.length,
289 iint->evm_status = evm_status;
294 static int evm_protected_xattr_common(const char *req_xattr_name,
299 struct xattr_list *xattr;
301 namelen = strlen(req_xattr_name);
302 list_for_each_entry_lockless(xattr, &evm_config_xattrnames, list) {
303 if (!all_xattrs && !xattr->enabled)
306 if ((strlen(xattr->name) == namelen)
307 && (strncmp(req_xattr_name, xattr->name, namelen) == 0)) {
311 if (strncmp(req_xattr_name,
312 xattr->name + XATTR_SECURITY_PREFIX_LEN,
313 strlen(req_xattr_name)) == 0) {
322 int evm_protected_xattr(const char *req_xattr_name)
324 return evm_protected_xattr_common(req_xattr_name, false);
327 int evm_protected_xattr_if_enabled(const char *req_xattr_name)
329 return evm_protected_xattr_common(req_xattr_name, true);
333 * evm_read_protected_xattrs - read EVM protected xattr names, lengths, values
334 * @dentry: dentry of the read xattrs
335 * @buffer: buffer xattr names, lengths or values are copied to
336 * @buffer_size: size of buffer
337 * @type: n: names, l: lengths, v: values
338 * @canonical_fmt: data format (true: little endian, false: native format)
340 * Read protected xattr names (separated by |), lengths (u32) or values for a
341 * given dentry and return the total size of copied data. If buffer is NULL,
342 * just return the total size.
344 * Returns the total size on success, a negative value on error.
346 int evm_read_protected_xattrs(struct dentry *dentry, u8 *buffer,
347 int buffer_size, char type, bool canonical_fmt)
349 struct xattr_list *xattr;
350 int rc, size, total_size = 0;
352 list_for_each_entry_lockless(xattr, &evm_config_xattrnames, list) {
353 rc = __vfs_getxattr(dentry, d_backing_inode(dentry),
354 xattr->name, NULL, 0);
355 if (rc < 0 && rc == -ENODATA)
362 size = strlen(xattr->name) + 1;
365 *(buffer + total_size - 1) = '|';
367 memcpy(buffer + total_size, xattr->name, size);
374 rc = (__force int)cpu_to_le32(rc);
376 *(u32 *)(buffer + total_size) = rc;
382 rc = __vfs_getxattr(dentry,
383 d_backing_inode(dentry), xattr->name,
385 buffer_size - total_size);
401 * evm_verifyxattr - verify the integrity of the requested xattr
402 * @dentry: object of the verify xattr
403 * @xattr_name: requested xattr
404 * @xattr_value: requested xattr value
405 * @xattr_value_len: requested xattr value length
406 * @iint: inode integrity metadata
408 * Calculate the HMAC for the given dentry and verify it against the stored
409 * security.evm xattr. For performance, use the xattr value and length
410 * previously retrieved to calculate the HMAC.
412 * Returns the xattr integrity status.
414 * This function requires the caller to lock the inode's i_mutex before it
417 enum integrity_status evm_verifyxattr(struct dentry *dentry,
418 const char *xattr_name,
419 void *xattr_value, size_t xattr_value_len,
420 struct integrity_iint_cache *iint)
422 if (!evm_key_loaded() || !evm_protected_xattr(xattr_name))
423 return INTEGRITY_UNKNOWN;
425 if (is_unsupported_fs(dentry))
426 return INTEGRITY_UNKNOWN;
429 iint = integrity_iint_find(d_backing_inode(dentry));
431 return INTEGRITY_UNKNOWN;
433 return evm_verify_hmac(dentry, xattr_name, xattr_value,
434 xattr_value_len, iint);
436 EXPORT_SYMBOL_GPL(evm_verifyxattr);
439 * evm_verify_current_integrity - verify the dentry's metadata integrity
440 * @dentry: pointer to the affected dentry
442 * Verify and return the dentry's metadata integrity. The exceptions are
443 * before EVM is initialized or in 'fix' mode.
445 static enum integrity_status evm_verify_current_integrity(struct dentry *dentry)
447 struct inode *inode = d_backing_inode(dentry);
449 if (!evm_key_loaded() || !S_ISREG(inode->i_mode) || evm_fixmode)
450 return INTEGRITY_PASS;
451 return evm_verify_hmac(dentry, NULL, NULL, 0, NULL);
455 * evm_xattr_change - check if passed xattr value differs from current value
456 * @idmap: idmap of the mount
457 * @dentry: pointer to the affected dentry
458 * @xattr_name: requested xattr
459 * @xattr_value: requested xattr value
460 * @xattr_value_len: requested xattr value length
462 * Check if passed xattr value differs from current value.
464 * Returns 1 if passed xattr value differs from current value, 0 otherwise.
466 static int evm_xattr_change(struct mnt_idmap *idmap,
467 struct dentry *dentry, const char *xattr_name,
468 const void *xattr_value, size_t xattr_value_len)
470 char *xattr_data = NULL;
473 rc = vfs_getxattr_alloc(&nop_mnt_idmap, dentry, xattr_name, &xattr_data,
480 if (rc == xattr_value_len)
481 rc = !!memcmp(xattr_value, xattr_data, rc);
491 * evm_protect_xattr - protect the EVM extended attribute
493 * Prevent security.evm from being modified or removed without the
494 * necessary permissions or when the existing value is invalid.
496 * The posix xattr acls are 'system' prefixed, which normally would not
497 * affect security.evm. An interesting side affect of writing posix xattr
498 * acls is their modifying of the i_mode, which is included in security.evm.
499 * For posix xattr acls only, permit security.evm, even if it currently
500 * doesn't exist, to be updated unless the EVM signature is immutable.
502 static int evm_protect_xattr(struct mnt_idmap *idmap,
503 struct dentry *dentry, const char *xattr_name,
504 const void *xattr_value, size_t xattr_value_len)
506 enum integrity_status evm_status;
508 if (strcmp(xattr_name, XATTR_NAME_EVM) == 0) {
509 if (!capable(CAP_SYS_ADMIN))
511 if (is_unsupported_fs(dentry))
513 } else if (!evm_protected_xattr(xattr_name)) {
514 if (!posix_xattr_acl(xattr_name))
516 if (is_unsupported_fs(dentry))
519 evm_status = evm_verify_current_integrity(dentry);
520 if ((evm_status == INTEGRITY_PASS) ||
521 (evm_status == INTEGRITY_NOXATTRS))
524 } else if (is_unsupported_fs(dentry))
527 evm_status = evm_verify_current_integrity(dentry);
528 if (evm_status == INTEGRITY_NOXATTRS) {
529 struct integrity_iint_cache *iint;
531 /* Exception if the HMAC is not going to be calculated. */
532 if (evm_hmac_disabled())
535 iint = integrity_iint_find(d_backing_inode(dentry));
536 if (iint && (iint->flags & IMA_NEW_FILE))
539 /* exception for pseudo filesystems */
540 if (dentry->d_sb->s_magic == TMPFS_MAGIC
541 || dentry->d_sb->s_magic == SYSFS_MAGIC)
544 integrity_audit_msg(AUDIT_INTEGRITY_METADATA,
545 dentry->d_inode, dentry->d_name.name,
547 integrity_status_msg[evm_status],
551 /* Exception if the HMAC is not going to be calculated. */
552 if (evm_hmac_disabled() && (evm_status == INTEGRITY_NOLABEL ||
553 evm_status == INTEGRITY_UNKNOWN))
557 * Writing other xattrs is safe for portable signatures, as portable
558 * signatures are immutable and can never be updated.
560 if (evm_status == INTEGRITY_FAIL_IMMUTABLE)
563 if (evm_status == INTEGRITY_PASS_IMMUTABLE &&
564 !evm_xattr_change(idmap, dentry, xattr_name, xattr_value,
568 if (evm_status != INTEGRITY_PASS &&
569 evm_status != INTEGRITY_PASS_IMMUTABLE)
570 integrity_audit_msg(AUDIT_INTEGRITY_METADATA, d_backing_inode(dentry),
571 dentry->d_name.name, "appraise_metadata",
572 integrity_status_msg[evm_status],
574 return evm_status == INTEGRITY_PASS ? 0 : -EPERM;
578 * evm_inode_setxattr - protect the EVM extended attribute
579 * @idmap: idmap of the mount
580 * @dentry: pointer to the affected dentry
581 * @xattr_name: pointer to the affected extended attribute name
582 * @xattr_value: pointer to the new extended attribute value
583 * @xattr_value_len: pointer to the new extended attribute value length
585 * Before allowing the 'security.evm' protected xattr to be updated,
586 * verify the existing value is valid. As only the kernel should have
587 * access to the EVM encrypted key needed to calculate the HMAC, prevent
588 * userspace from writing HMAC value. Writing 'security.evm' requires
589 * requires CAP_SYS_ADMIN privileges.
591 int evm_inode_setxattr(struct mnt_idmap *idmap, struct dentry *dentry,
592 const char *xattr_name, const void *xattr_value,
593 size_t xattr_value_len)
595 const struct evm_ima_xattr_data *xattr_data = xattr_value;
597 /* Policy permits modification of the protected xattrs even though
598 * there's no HMAC key loaded
600 if (evm_initialized & EVM_ALLOW_METADATA_WRITES)
603 if (strcmp(xattr_name, XATTR_NAME_EVM) == 0) {
604 if (!xattr_value_len)
606 if (xattr_data->type != EVM_IMA_XATTR_DIGSIG &&
607 xattr_data->type != EVM_XATTR_PORTABLE_DIGSIG)
610 return evm_protect_xattr(idmap, dentry, xattr_name, xattr_value,
615 * evm_inode_removexattr - protect the EVM extended attribute
616 * @idmap: idmap of the mount
617 * @dentry: pointer to the affected dentry
618 * @xattr_name: pointer to the affected extended attribute name
620 * Removing 'security.evm' requires CAP_SYS_ADMIN privileges and that
621 * the current value is valid.
623 int evm_inode_removexattr(struct mnt_idmap *idmap,
624 struct dentry *dentry, const char *xattr_name)
626 /* Policy permits modification of the protected xattrs even though
627 * there's no HMAC key loaded
629 if (evm_initialized & EVM_ALLOW_METADATA_WRITES)
632 return evm_protect_xattr(idmap, dentry, xattr_name, NULL, 0);
635 #ifdef CONFIG_FS_POSIX_ACL
636 static int evm_inode_set_acl_change(struct mnt_idmap *idmap,
637 struct dentry *dentry, const char *name,
638 struct posix_acl *kacl)
643 struct inode *inode = d_backing_inode(dentry);
648 rc = posix_acl_update_mode(idmap, inode, &mode, &kacl);
649 if (rc || (inode->i_mode != mode))
655 static inline int evm_inode_set_acl_change(struct mnt_idmap *idmap,
656 struct dentry *dentry,
658 struct posix_acl *kacl)
665 * evm_inode_set_acl - protect the EVM extended attribute from posix acls
666 * @idmap: idmap of the idmapped mount
667 * @dentry: pointer to the affected dentry
668 * @acl_name: name of the posix acl
669 * @kacl: pointer to the posix acls
671 * Prevent modifying posix acls causing the EVM HMAC to be re-calculated
672 * and 'security.evm' xattr updated, unless the existing 'security.evm' is
675 int evm_inode_set_acl(struct mnt_idmap *idmap, struct dentry *dentry,
676 const char *acl_name, struct posix_acl *kacl)
678 enum integrity_status evm_status;
680 /* Policy permits modification of the protected xattrs even though
681 * there's no HMAC key loaded
683 if (evm_initialized & EVM_ALLOW_METADATA_WRITES)
686 evm_status = evm_verify_current_integrity(dentry);
687 if ((evm_status == INTEGRITY_PASS) ||
688 (evm_status == INTEGRITY_NOXATTRS))
691 /* Exception if the HMAC is not going to be calculated. */
692 if (evm_hmac_disabled() && (evm_status == INTEGRITY_NOLABEL ||
693 evm_status == INTEGRITY_UNKNOWN))
697 * Writing other xattrs is safe for portable signatures, as portable
698 * signatures are immutable and can never be updated.
700 if (evm_status == INTEGRITY_FAIL_IMMUTABLE)
703 if (evm_status == INTEGRITY_PASS_IMMUTABLE &&
704 !evm_inode_set_acl_change(idmap, dentry, acl_name, kacl))
707 if (evm_status != INTEGRITY_PASS_IMMUTABLE)
708 integrity_audit_msg(AUDIT_INTEGRITY_METADATA, d_backing_inode(dentry),
709 dentry->d_name.name, "appraise_metadata",
710 integrity_status_msg[evm_status],
715 static void evm_reset_status(struct inode *inode)
717 struct integrity_iint_cache *iint;
719 iint = integrity_iint_find(inode);
721 iint->evm_status = INTEGRITY_UNKNOWN;
725 * evm_revalidate_status - report whether EVM status re-validation is necessary
726 * @xattr_name: pointer to the affected extended attribute name
728 * Report whether callers of evm_verifyxattr() should re-validate the
731 * Return true if re-validation is necessary, false otherwise.
733 bool evm_revalidate_status(const char *xattr_name)
735 if (!evm_key_loaded())
738 /* evm_inode_post_setattr() passes NULL */
742 if (!evm_protected_xattr(xattr_name) && !posix_xattr_acl(xattr_name) &&
743 strcmp(xattr_name, XATTR_NAME_EVM))
750 * evm_inode_post_setxattr - update 'security.evm' to reflect the changes
751 * @dentry: pointer to the affected dentry
752 * @xattr_name: pointer to the affected extended attribute name
753 * @xattr_value: pointer to the new extended attribute value
754 * @xattr_value_len: pointer to the new extended attribute value length
756 * Update the HMAC stored in 'security.evm' to reflect the change.
758 * No need to take the i_mutex lock here, as this function is called from
759 * __vfs_setxattr_noperm(). The caller of which has taken the inode's
762 void evm_inode_post_setxattr(struct dentry *dentry, const char *xattr_name,
763 const void *xattr_value, size_t xattr_value_len)
765 if (!evm_revalidate_status(xattr_name))
768 evm_reset_status(dentry->d_inode);
770 if (!strcmp(xattr_name, XATTR_NAME_EVM))
773 if (!(evm_initialized & EVM_INIT_HMAC))
776 if (is_unsupported_fs(dentry))
779 evm_update_evmxattr(dentry, xattr_name, xattr_value, xattr_value_len);
783 * evm_inode_post_removexattr - update 'security.evm' after removing the xattr
784 * @dentry: pointer to the affected dentry
785 * @xattr_name: pointer to the affected extended attribute name
787 * Update the HMAC stored in 'security.evm' to reflect removal of the xattr.
789 * No need to take the i_mutex lock here, as this function is called from
790 * vfs_removexattr() which takes the i_mutex.
792 void evm_inode_post_removexattr(struct dentry *dentry, const char *xattr_name)
794 if (!evm_revalidate_status(xattr_name))
797 evm_reset_status(dentry->d_inode);
799 if (!strcmp(xattr_name, XATTR_NAME_EVM))
802 if (!(evm_initialized & EVM_INIT_HMAC))
805 evm_update_evmxattr(dentry, xattr_name, NULL, 0);
808 static int evm_attr_change(struct mnt_idmap *idmap,
809 struct dentry *dentry, struct iattr *attr)
811 struct inode *inode = d_backing_inode(dentry);
812 unsigned int ia_valid = attr->ia_valid;
814 if (!i_uid_needs_update(idmap, attr, inode) &&
815 !i_gid_needs_update(idmap, attr, inode) &&
816 (!(ia_valid & ATTR_MODE) || attr->ia_mode == inode->i_mode))
823 * evm_inode_setattr - prevent updating an invalid EVM extended attribute
824 * @idmap: idmap of the mount
825 * @dentry: pointer to the affected dentry
826 * @attr: iattr structure containing the new file attributes
828 * Permit update of file attributes when files have a valid EVM signature,
829 * except in the case of them having an immutable portable signature.
831 int evm_inode_setattr(struct mnt_idmap *idmap, struct dentry *dentry,
834 unsigned int ia_valid = attr->ia_valid;
835 enum integrity_status evm_status;
837 /* Policy permits modification of the protected attrs even though
838 * there's no HMAC key loaded
840 if (evm_initialized & EVM_ALLOW_METADATA_WRITES)
843 if (is_unsupported_fs(dentry))
846 if (!(ia_valid & (ATTR_MODE | ATTR_UID | ATTR_GID)))
849 evm_status = evm_verify_current_integrity(dentry);
851 * Writing attrs is safe for portable signatures, as portable signatures
852 * are immutable and can never be updated.
854 if ((evm_status == INTEGRITY_PASS) ||
855 (evm_status == INTEGRITY_NOXATTRS) ||
856 (evm_status == INTEGRITY_FAIL_IMMUTABLE) ||
857 (evm_hmac_disabled() && (evm_status == INTEGRITY_NOLABEL ||
858 evm_status == INTEGRITY_UNKNOWN)))
861 if (evm_status == INTEGRITY_PASS_IMMUTABLE &&
862 !evm_attr_change(idmap, dentry, attr))
865 integrity_audit_msg(AUDIT_INTEGRITY_METADATA, d_backing_inode(dentry),
866 dentry->d_name.name, "appraise_metadata",
867 integrity_status_msg[evm_status], -EPERM, 0);
872 * evm_inode_post_setattr - update 'security.evm' after modifying metadata
873 * @dentry: pointer to the affected dentry
874 * @ia_valid: for the UID and GID status
876 * For now, update the HMAC stored in 'security.evm' to reflect UID/GID
879 * This function is called from notify_change(), which expects the caller
880 * to lock the inode's i_mutex.
882 void evm_inode_post_setattr(struct dentry *dentry, int ia_valid)
884 if (!evm_revalidate_status(NULL))
887 evm_reset_status(dentry->d_inode);
889 if (!(evm_initialized & EVM_INIT_HMAC))
892 if (is_unsupported_fs(dentry))
895 if (ia_valid & (ATTR_MODE | ATTR_UID | ATTR_GID))
896 evm_update_evmxattr(dentry, NULL, NULL, 0);
899 int evm_inode_copy_up_xattr(const char *name)
901 if (strcmp(name, XATTR_NAME_EVM) == 0)
902 return 1; /* Discard */
907 * evm_inode_init_security - initializes security.evm HMAC value
909 int evm_inode_init_security(struct inode *inode, struct inode *dir,
910 const struct qstr *qstr, struct xattr *xattrs,
913 struct evm_xattr *xattr_data;
914 struct xattr *xattr, *evm_xattr;
915 bool evm_protected_xattrs = false;
918 if (!(evm_initialized & EVM_INIT_HMAC) || !xattrs)
922 * security_inode_init_security() makes sure that the xattrs array is
923 * contiguous, there is enough space for security.evm, and that there is
924 * a terminator at the end of the array.
926 for (xattr = xattrs; xattr->name; xattr++) {
927 if (evm_protected_xattr(xattr->name))
928 evm_protected_xattrs = true;
931 /* EVM xattr not needed. */
932 if (!evm_protected_xattrs)
935 evm_xattr = lsm_get_xattr_slot(xattrs, xattr_count);
937 * Array terminator (xattr name = NULL) must be the first non-filled
940 WARN_ONCE(evm_xattr != xattr,
941 "%s: xattrs terminator is not the first non-filled slot\n",
944 xattr_data = kzalloc(sizeof(*xattr_data), GFP_NOFS);
948 xattr_data->data.type = EVM_XATTR_HMAC;
949 rc = evm_init_hmac(inode, xattrs, xattr_data->digest);
953 evm_xattr->value = xattr_data;
954 evm_xattr->value_len = sizeof(*xattr_data);
955 evm_xattr->name = XATTR_EVM_SUFFIX;
961 EXPORT_SYMBOL_GPL(evm_inode_init_security);
963 #ifdef CONFIG_EVM_LOAD_X509
964 void __init evm_load_x509(void)
968 rc = integrity_load_x509(INTEGRITY_KEYRING_EVM, CONFIG_EVM_X509_PATH);
970 evm_initialized |= EVM_INIT_X509;
974 static int __init init_evm(void)
977 struct list_head *pos, *q;
981 error = integrity_init_keyring(INTEGRITY_KEYRING_EVM);
985 error = evm_init_secfs();
987 pr_info("Error registering secfs\n");
993 if (!list_empty(&evm_config_xattrnames)) {
994 list_for_each_safe(pos, q, &evm_config_xattrnames)
1002 late_initcall(init_evm);