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-rw-r--r--security/integrity/evm/evm.h8
-rw-r--r--security/integrity/evm/evm_crypto.c25
-rw-r--r--security/integrity/evm/evm_main.c92
3 files changed, 96 insertions, 29 deletions
diff --git a/security/integrity/evm/evm.h b/security/integrity/evm/evm.h
index eb1a2c343bd7..51aba5a54275 100644
--- a/security/integrity/evm/evm.h
+++ b/security/integrity/evm/evm.h
@@ -39,6 +39,7 @@ struct xattr_list {
struct evm_iint_cache {
unsigned long flags;
enum integrity_status evm_status:4;
+ struct integrity_inode_attributes metadata_inode;
};
extern struct lsm_blob_sizes evm_blob_sizes;
@@ -61,7 +62,7 @@ extern int evm_hmac_attrs;
extern struct list_head evm_config_xattrnames;
struct evm_digest {
- struct ima_digest_data hdr;
+ struct ima_digest_data_hdr hdr;
char digest[IMA_MAX_DIGEST_SIZE];
} __packed;
@@ -74,11 +75,12 @@ int evm_update_evmxattr(struct dentry *dentry,
size_t req_xattr_value_len);
int evm_calc_hmac(struct dentry *dentry, const char *req_xattr_name,
const char *req_xattr_value,
- size_t req_xattr_value_len, struct evm_digest *data);
+ size_t req_xattr_value_len, struct evm_digest *data,
+ struct evm_iint_cache *iint);
int evm_calc_hash(struct dentry *dentry, const char *req_xattr_name,
const char *req_xattr_value,
size_t req_xattr_value_len, char type,
- struct evm_digest *data);
+ struct evm_digest *data, struct evm_iint_cache *iint);
int evm_init_hmac(struct inode *inode, const struct xattr *xattrs,
char *hmac_val);
int evm_init_secfs(void);
diff --git a/security/integrity/evm/evm_crypto.c b/security/integrity/evm/evm_crypto.c
index 7552d49d0725..7c06ffd633d2 100644
--- a/security/integrity/evm/evm_crypto.c
+++ b/security/integrity/evm/evm_crypto.c
@@ -221,9 +221,10 @@ static int evm_calc_hmac_or_hash(struct dentry *dentry,
const char *req_xattr_name,
const char *req_xattr_value,
size_t req_xattr_value_len,
- uint8_t type, struct evm_digest *data)
+ uint8_t type, struct evm_digest *data,
+ struct evm_iint_cache *iint)
{
- struct inode *inode = d_backing_inode(dentry);
+ struct inode *inode = d_inode(d_real(dentry, D_REAL_METADATA));
struct xattr_list *xattr;
struct shash_desc *desc;
size_t xattr_size = 0;
@@ -231,6 +232,7 @@ static int evm_calc_hmac_or_hash(struct dentry *dentry,
int error;
int size, user_space_size;
bool ima_present = false;
+ u64 i_version = 0;
if (!(inode->i_opflags & IOP_XATTR) ||
inode->i_sb->s_user_ns != &init_user_ns)
@@ -294,6 +296,13 @@ static int evm_calc_hmac_or_hash(struct dentry *dentry,
}
hmac_add_misc(desc, inode, type, data->digest);
+ if (inode != d_backing_inode(dentry) && iint) {
+ if (IS_I_VERSION(inode))
+ i_version = inode_query_iversion(inode);
+ integrity_inode_attrs_store(&iint->metadata_inode, i_version,
+ inode);
+ }
+
/* Portable EVM signatures must include an IMA hash */
if (type == EVM_XATTR_PORTABLE_DIGSIG && !ima_present)
error = -EPERM;
@@ -305,18 +314,19 @@ out:
int evm_calc_hmac(struct dentry *dentry, const char *req_xattr_name,
const char *req_xattr_value, size_t req_xattr_value_len,
- struct evm_digest *data)
+ struct evm_digest *data, struct evm_iint_cache *iint)
{
return evm_calc_hmac_or_hash(dentry, req_xattr_name, req_xattr_value,
- req_xattr_value_len, EVM_XATTR_HMAC, data);
+ req_xattr_value_len, EVM_XATTR_HMAC, data,
+ iint);
}
int evm_calc_hash(struct dentry *dentry, const char *req_xattr_name,
const char *req_xattr_value, size_t req_xattr_value_len,
- char type, struct evm_digest *data)
+ char type, struct evm_digest *data, struct evm_iint_cache *iint)
{
return evm_calc_hmac_or_hash(dentry, req_xattr_name, req_xattr_value,
- req_xattr_value_len, type, data);
+ req_xattr_value_len, type, data, iint);
}
static int evm_is_immutable(struct dentry *dentry, struct inode *inode)
@@ -357,6 +367,7 @@ int evm_update_evmxattr(struct dentry *dentry, const char *xattr_name,
const char *xattr_value, size_t xattr_value_len)
{
struct inode *inode = d_backing_inode(dentry);
+ struct evm_iint_cache *iint = evm_iint_inode(inode);
struct evm_digest data;
int rc = 0;
@@ -372,7 +383,7 @@ int evm_update_evmxattr(struct dentry *dentry, const char *xattr_name,
data.hdr.algo = HASH_ALGO_SHA1;
rc = evm_calc_hmac(dentry, xattr_name, xattr_value,
- xattr_value_len, &data);
+ xattr_value_len, &data, iint);
if (rc == 0) {
data.hdr.xattr.sha1.type = EVM_XATTR_HMAC;
rc = __vfs_setxattr_noperm(&nop_mnt_idmap, dentry,
diff --git a/security/integrity/evm/evm_main.c b/security/integrity/evm/evm_main.c
index 81dbade5b9b3..6924ed508ebd 100644
--- a/security/integrity/evm/evm_main.c
+++ b/security/integrity/evm/evm_main.c
@@ -151,11 +151,11 @@ static int evm_find_protected_xattrs(struct dentry *dentry)
return count;
}
-static int is_unsupported_fs(struct dentry *dentry)
+static int is_unsupported_hmac_fs(struct dentry *dentry)
{
struct inode *inode = d_backing_inode(dentry);
- if (inode->i_sb->s_iflags & SB_I_EVM_UNSUPPORTED) {
+ if (inode->i_sb->s_iflags & SB_I_EVM_HMAC_UNSUPPORTED) {
pr_info_once("%s not supported\n", inode->i_sb->s_type->name);
return 1;
}
@@ -192,7 +192,12 @@ static enum integrity_status evm_verify_hmac(struct dentry *dentry,
iint->evm_status == INTEGRITY_PASS_IMMUTABLE))
return iint->evm_status;
- if (is_unsupported_fs(dentry))
+ /*
+ * On unsupported filesystems without EVM_INIT_X509 enabled, skip
+ * signature verification.
+ */
+ if (!(evm_initialized & EVM_INIT_X509) &&
+ is_unsupported_hmac_fs(dentry))
return INTEGRITY_UNKNOWN;
/* if status is not PASS, try to check again - against -ENOMEM */
@@ -226,7 +231,7 @@ static enum integrity_status evm_verify_hmac(struct dentry *dentry,
digest.hdr.algo = HASH_ALGO_SHA1;
rc = evm_calc_hmac(dentry, xattr_name, xattr_value,
- xattr_value_len, &digest);
+ xattr_value_len, &digest, iint);
if (rc)
break;
rc = crypto_memneq(xattr_data->data, digest.digest,
@@ -247,7 +252,8 @@ static enum integrity_status evm_verify_hmac(struct dentry *dentry,
hdr = (struct signature_v2_hdr *)xattr_data;
digest.hdr.algo = hdr->hash_algo;
rc = evm_calc_hash(dentry, xattr_name, xattr_value,
- xattr_value_len, xattr_data->type, &digest);
+ xattr_value_len, xattr_data->type, &digest,
+ iint);
if (rc)
break;
rc = integrity_digsig_verify(INTEGRITY_KEYRING_EVM,
@@ -260,7 +266,8 @@ static enum integrity_status evm_verify_hmac(struct dentry *dentry,
evm_status = INTEGRITY_PASS_IMMUTABLE;
} else if (!IS_RDONLY(inode) &&
!(inode->i_sb->s_readonly_remount) &&
- !IS_IMMUTABLE(inode)) {
+ !IS_IMMUTABLE(inode) &&
+ !is_unsupported_hmac_fs(dentry)) {
evm_update_evmxattr(dentry, xattr_name,
xattr_value,
xattr_value_len);
@@ -418,9 +425,6 @@ enum integrity_status evm_verifyxattr(struct dentry *dentry,
if (!evm_key_loaded() || !evm_protected_xattr(xattr_name))
return INTEGRITY_UNKNOWN;
- if (is_unsupported_fs(dentry))
- return INTEGRITY_UNKNOWN;
-
return evm_verify_hmac(dentry, xattr_name, xattr_value,
xattr_value_len);
}
@@ -499,12 +503,12 @@ static int evm_protect_xattr(struct mnt_idmap *idmap,
if (strcmp(xattr_name, XATTR_NAME_EVM) == 0) {
if (!capable(CAP_SYS_ADMIN))
return -EPERM;
- if (is_unsupported_fs(dentry))
+ if (is_unsupported_hmac_fs(dentry))
return -EPERM;
} else if (!evm_protected_xattr(xattr_name)) {
if (!posix_xattr_acl(xattr_name))
return 0;
- if (is_unsupported_fs(dentry))
+ if (is_unsupported_hmac_fs(dentry))
return 0;
evm_status = evm_verify_current_integrity(dentry);
@@ -512,7 +516,7 @@ static int evm_protect_xattr(struct mnt_idmap *idmap,
(evm_status == INTEGRITY_NOXATTRS))
return 0;
goto out;
- } else if (is_unsupported_fs(dentry))
+ } else if (is_unsupported_hmac_fs(dentry))
return 0;
evm_status = evm_verify_current_integrity(dentry);
@@ -734,6 +738,31 @@ static void evm_reset_status(struct inode *inode)
}
/**
+ * evm_metadata_changed: Detect changes to the metadata
+ * @inode: a file's inode
+ * @metadata_inode: metadata inode
+ *
+ * On a stacked filesystem detect whether the metadata has changed. If this is
+ * the case reset the evm_status associated with the inode that represents the
+ * file.
+ */
+bool evm_metadata_changed(struct inode *inode, struct inode *metadata_inode)
+{
+ struct evm_iint_cache *iint = evm_iint_inode(inode);
+ bool ret = false;
+
+ if (iint) {
+ ret = (!IS_I_VERSION(metadata_inode) ||
+ integrity_inode_attrs_changed(&iint->metadata_inode,
+ metadata_inode));
+ if (ret)
+ iint->evm_status = INTEGRITY_UNKNOWN;
+ }
+
+ return ret;
+}
+
+/**
* evm_revalidate_status - report whether EVM status re-validation is necessary
* @xattr_name: pointer to the affected extended attribute name
*
@@ -789,7 +818,7 @@ static void evm_inode_post_setxattr(struct dentry *dentry,
if (!(evm_initialized & EVM_INIT_HMAC))
return;
- if (is_unsupported_fs(dentry))
+ if (is_unsupported_hmac_fs(dentry))
return;
evm_update_evmxattr(dentry, xattr_name, xattr_value, xattr_value_len);
@@ -888,7 +917,7 @@ static int evm_inode_setattr(struct mnt_idmap *idmap, struct dentry *dentry,
if (evm_initialized & EVM_ALLOW_METADATA_WRITES)
return 0;
- if (is_unsupported_fs(dentry))
+ if (is_unsupported_hmac_fs(dentry))
return 0;
if (!(ia_valid & (ATTR_MODE | ATTR_UID | ATTR_GID)))
@@ -939,18 +968,43 @@ static void evm_inode_post_setattr(struct mnt_idmap *idmap,
if (!(evm_initialized & EVM_INIT_HMAC))
return;
- if (is_unsupported_fs(dentry))
+ if (is_unsupported_hmac_fs(dentry))
return;
if (ia_valid & (ATTR_MODE | ATTR_UID | ATTR_GID))
evm_update_evmxattr(dentry, NULL, NULL, 0);
}
-static int evm_inode_copy_up_xattr(const char *name)
+static int evm_inode_copy_up_xattr(struct dentry *src, const char *name)
{
- if (strcmp(name, XATTR_NAME_EVM) == 0)
- return 1; /* Discard */
- return -EOPNOTSUPP;
+ struct evm_ima_xattr_data *xattr_data = NULL;
+ int rc;
+
+ if (strcmp(name, XATTR_NAME_EVM) != 0)
+ return -EOPNOTSUPP;
+
+ /* first need to know the sig type */
+ rc = vfs_getxattr_alloc(&nop_mnt_idmap, src, XATTR_NAME_EVM,
+ (char **)&xattr_data, 0, GFP_NOFS);
+ if (rc <= 0)
+ return -EPERM;
+
+ if (rc < offsetof(struct evm_ima_xattr_data, type) +
+ sizeof(xattr_data->type))
+ return -EPERM;
+
+ switch (xattr_data->type) {
+ case EVM_XATTR_PORTABLE_DIGSIG:
+ rc = 0; /* allow copy-up */
+ break;
+ case EVM_XATTR_HMAC:
+ case EVM_IMA_XATTR_DIGSIG:
+ default:
+ rc = -ECANCELED; /* discard */
+ }
+
+ kfree(xattr_data);
+ return rc;
}
/*
generated by cgit v1.2.3 (git 2.25.1) at 2024-11-11 06:27:52 +0000