diff options
author | Linus Torvalds <torvalds@linux-foundation.org> | 2024-05-15 08:43:02 -0700 |
---|---|---|
committer | Linus Torvalds <torvalds@linux-foundation.org> | 2024-05-15 08:43:02 -0700 |
commit | 353ad6c0839431146fdee3ff16f9dd17a2809ee4 (patch) | |
tree | 5509e6bab7847132990755796bafc7611a779593 | |
parent | ccae19c6239ae810242d2edc03b02bdcc12fc5ab (diff) | |
parent | 9fa8e76250082a45d0d3dad525419ab98bd01658 (diff) |
Merge tag 'integrity-v6.10' of ssh://ra.kernel.org/pub/scm/linux/kernel/git/zohar/linux-integrity
Pull integrity updates from Mimi Zohar:
"Two IMA changes, one EVM change, a use after free bug fix, and a code
cleanup to address "-Wflex-array-member-not-at-end" warnings:
- The existing IMA {ascii, binary}_runtime_measurements lists include
a hard coded SHA1 hash. To address this limitation, define per TPM
enabled hash algorithm {ascii, binary}_runtime_measurements lists
- Close an IMA integrity init_module syscall measurement gap by
defining a new critical-data record
- Enable (partial) EVM support on stacked filesystems (overlayfs).
Only EVM portable & immutable file signatures are copied up, since
they do not contain filesystem specific metadata"
* tag 'integrity-v6.10' of ssh://ra.kernel.org/pub/scm/linux/kernel/git/zohar/linux-integrity:
ima: add crypto agility support for template-hash algorithm
evm: Rename is_unsupported_fs to is_unsupported_hmac_fs
fs: Rename SB_I_EVM_UNSUPPORTED to SB_I_EVM_HMAC_UNSUPPORTED
evm: Enforce signatures on unsupported filesystem for EVM_INIT_X509
ima: re-evaluate file integrity on file metadata change
evm: Store and detect metadata inode attributes changes
ima: Move file-change detection variables into new structure
evm: Use the metadata inode to calculate metadata hash
evm: Implement per signature type decision in security_inode_copy_up_xattr
security: allow finer granularity in permitting copy-up of security xattrs
ima: Rename backing_inode to real_inode
integrity: Avoid -Wflex-array-member-not-at-end warnings
ima: define an init_module critical data record
ima: Fix use-after-free on a dentry's dname.name
-rw-r--r-- | fs/overlayfs/copy_up.c | 2 | ||||
-rw-r--r-- | fs/overlayfs/super.c | 2 | ||||
-rw-r--r-- | include/linux/evm.h | 8 | ||||
-rw-r--r-- | include/linux/fs.h | 2 | ||||
-rw-r--r-- | include/linux/integrity.h | 34 | ||||
-rw-r--r-- | include/linux/lsm_hook_defs.h | 3 | ||||
-rw-r--r-- | include/linux/security.h | 4 | ||||
-rw-r--r-- | security/integrity/evm/evm.h | 8 | ||||
-rw-r--r-- | security/integrity/evm/evm_crypto.c | 25 | ||||
-rw-r--r-- | security/integrity/evm/evm_main.c | 92 | ||||
-rw-r--r-- | security/integrity/ima/ima.h | 12 | ||||
-rw-r--r-- | security/integrity/ima/ima_api.c | 32 | ||||
-rw-r--r-- | security/integrity/ima/ima_appraise.c | 4 | ||||
-rw-r--r-- | security/integrity/ima/ima_crypto.c | 7 | ||||
-rw-r--r-- | security/integrity/ima/ima_fs.c | 134 | ||||
-rw-r--r-- | security/integrity/ima/ima_iint.c | 2 | ||||
-rw-r--r-- | security/integrity/ima/ima_init.c | 6 | ||||
-rw-r--r-- | security/integrity/ima/ima_kexec.c | 1 | ||||
-rw-r--r-- | security/integrity/ima/ima_main.c | 44 | ||||
-rw-r--r-- | security/integrity/ima/ima_template_lib.c | 27 | ||||
-rw-r--r-- | security/integrity/integrity.h | 12 | ||||
-rw-r--r-- | security/security.c | 5 | ||||
-rw-r--r-- | security/selinux/hooks.c | 2 | ||||
-rw-r--r-- | security/smack/smack_lsm.c | 2 |
24 files changed, 374 insertions, 96 deletions
diff --git a/fs/overlayfs/copy_up.c b/fs/overlayfs/copy_up.c index 0762575a1e70..a5ef2005a2cc 100644 --- a/fs/overlayfs/copy_up.c +++ b/fs/overlayfs/copy_up.c @@ -114,7 +114,7 @@ int ovl_copy_xattr(struct super_block *sb, const struct path *oldpath, struct de if (ovl_is_private_xattr(sb, name)) continue; - error = security_inode_copy_up_xattr(name); + error = security_inode_copy_up_xattr(old, name); if (error < 0 && error != -EOPNOTSUPP) break; if (error == 1) { diff --git a/fs/overlayfs/super.c b/fs/overlayfs/super.c index a40fc7e05525..06a231970cb5 100644 --- a/fs/overlayfs/super.c +++ b/fs/overlayfs/super.c @@ -1460,7 +1460,7 @@ int ovl_fill_super(struct super_block *sb, struct fs_context *fc) * lead to unexpected results. */ sb->s_iflags |= SB_I_NOUMASK; - sb->s_iflags |= SB_I_EVM_UNSUPPORTED; + sb->s_iflags |= SB_I_EVM_HMAC_UNSUPPORTED; err = -ENOMEM; root_dentry = ovl_get_root(sb, ctx->upper.dentry, oe); diff --git a/include/linux/evm.h b/include/linux/evm.h index d48d6da32315..ddece4a6b25d 100644 --- a/include/linux/evm.h +++ b/include/linux/evm.h @@ -26,6 +26,8 @@ extern int evm_protected_xattr_if_enabled(const char *req_xattr_name); extern int evm_read_protected_xattrs(struct dentry *dentry, u8 *buffer, int buffer_size, char type, bool canonical_fmt); +extern bool evm_metadata_changed(struct inode *inode, + struct inode *metadata_inode); #ifdef CONFIG_FS_POSIX_ACL extern int posix_xattr_acl(const char *xattrname); #else @@ -76,5 +78,11 @@ static inline int evm_read_protected_xattrs(struct dentry *dentry, u8 *buffer, return -EOPNOTSUPP; } +static inline bool evm_metadata_changed(struct inode *inode, + struct inode *metadata_inode) +{ + return false; +} + #endif /* CONFIG_EVM */ #endif /* LINUX_EVM_H */ diff --git a/include/linux/fs.h b/include/linux/fs.h index de946a1fd845..b7b9b3b79acc 100644 --- a/include/linux/fs.h +++ b/include/linux/fs.h @@ -1174,7 +1174,7 @@ extern int send_sigurg(struct fown_struct *fown); #define SB_I_USERNS_VISIBLE 0x00000010 /* fstype already mounted */ #define SB_I_IMA_UNVERIFIABLE_SIGNATURE 0x00000020 #define SB_I_UNTRUSTED_MOUNTER 0x00000040 -#define SB_I_EVM_UNSUPPORTED 0x00000080 +#define SB_I_EVM_HMAC_UNSUPPORTED 0x00000080 #define SB_I_SKIP_SYNC 0x00000100 /* Skip superblock at global sync */ #define SB_I_PERSB_BDI 0x00000200 /* has a per-sb bdi */ diff --git a/include/linux/integrity.h b/include/linux/integrity.h index 459b79683783..f5842372359b 100644 --- a/include/linux/integrity.h +++ b/include/linux/integrity.h @@ -8,6 +8,7 @@ #define _LINUX_INTEGRITY_H #include <linux/fs.h> +#include <linux/iversion.h> enum integrity_status { INTEGRITY_PASS = 0, @@ -28,4 +29,37 @@ static inline void integrity_load_keys(void) } #endif /* CONFIG_INTEGRITY */ +/* An inode's attributes for detection of changes */ +struct integrity_inode_attributes { + u64 version; /* track inode changes */ + unsigned long ino; + dev_t dev; +}; + +/* + * On stacked filesystems the i_version alone is not enough to detect file data + * or metadata change. Additional metadata is required. + */ +static inline void +integrity_inode_attrs_store(struct integrity_inode_attributes *attrs, + u64 i_version, const struct inode *inode) +{ + attrs->version = i_version; + attrs->dev = inode->i_sb->s_dev; + attrs->ino = inode->i_ino; +} + +/* + * On stacked filesystems detect whether the inode or its content has changed. + */ +static inline bool +integrity_inode_attrs_changed(const struct integrity_inode_attributes *attrs, + const struct inode *inode) +{ + return (inode->i_sb->s_dev != attrs->dev || + inode->i_ino != attrs->ino || + !inode_eq_iversion(inode, attrs->version)); +} + + #endif /* _LINUX_INTEGRITY_H */ diff --git a/include/linux/lsm_hook_defs.h b/include/linux/lsm_hook_defs.h index 334e00efbde4..f804b76cde44 100644 --- a/include/linux/lsm_hook_defs.h +++ b/include/linux/lsm_hook_defs.h @@ -176,7 +176,8 @@ LSM_HOOK(int, 0, inode_listsecurity, struct inode *inode, char *buffer, size_t buffer_size) LSM_HOOK(void, LSM_RET_VOID, inode_getsecid, struct inode *inode, u32 *secid) LSM_HOOK(int, 0, inode_copy_up, struct dentry *src, struct cred **new) -LSM_HOOK(int, -EOPNOTSUPP, inode_copy_up_xattr, const char *name) +LSM_HOOK(int, -EOPNOTSUPP, inode_copy_up_xattr, struct dentry *src, + const char *name) LSM_HOOK(int, 0, kernfs_init_security, struct kernfs_node *kn_dir, struct kernfs_node *kn) LSM_HOOK(int, 0, file_permission, struct file *file, int mask) diff --git a/include/linux/security.h b/include/linux/security.h index 41a8f667bdfa..21cf70346b33 100644 --- a/include/linux/security.h +++ b/include/linux/security.h @@ -398,7 +398,7 @@ int security_inode_setsecurity(struct inode *inode, const char *name, const void int security_inode_listsecurity(struct inode *inode, char *buffer, size_t buffer_size); void security_inode_getsecid(struct inode *inode, u32 *secid); int security_inode_copy_up(struct dentry *src, struct cred **new); -int security_inode_copy_up_xattr(const char *name); +int security_inode_copy_up_xattr(struct dentry *src, const char *name); int security_kernfs_init_security(struct kernfs_node *kn_dir, struct kernfs_node *kn); int security_file_permission(struct file *file, int mask); @@ -1016,7 +1016,7 @@ static inline int security_kernfs_init_security(struct kernfs_node *kn_dir, return 0; } -static inline int security_inode_copy_up_xattr(const char *name) +static inline int security_inode_copy_up_xattr(struct dentry *src, const char *name) { return -EOPNOTSUPP; } 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..62fe66dd53ce 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 = 1; /* discard */ + } + + kfree(xattr_data); + return rc; } /* diff --git a/security/integrity/ima/ima.h b/security/integrity/ima/ima.h index 11d7c0332207..3e568126cd48 100644 --- a/security/integrity/ima/ima.h +++ b/security/integrity/ima/ima.h @@ -49,11 +49,19 @@ extern int ima_policy_flag; /* bitset of digests algorithms allowed in the setxattr hook */ extern atomic_t ima_setxattr_allowed_hash_algorithms; +/* IMA hash algorithm description */ +struct ima_algo_desc { + struct crypto_shash *tfm; + enum hash_algo algo; +}; + /* set during initialization */ extern int ima_hash_algo __ro_after_init; extern int ima_sha1_idx __ro_after_init; extern int ima_hash_algo_idx __ro_after_init; extern int ima_extra_slots __ro_after_init; +extern struct ima_algo_desc *ima_algo_array __ro_after_init; + extern int ima_appraise; extern struct tpm_chip *ima_tpm_chip; extern const char boot_aggregate_name[]; @@ -175,12 +183,10 @@ struct ima_kexec_hdr { /* IMA integrity metadata associated with an inode */ struct ima_iint_cache { struct mutex mutex; /* protects: version, flags, digest */ - u64 version; /* track inode changes */ + struct integrity_inode_attributes real_inode; unsigned long flags; unsigned long measured_pcrs; unsigned long atomic_flags; - unsigned long real_ino; - dev_t real_dev; enum integrity_status ima_file_status:4; enum integrity_status ima_mmap_status:4; enum integrity_status ima_bprm_status:4; diff --git a/security/integrity/ima/ima_api.c b/security/integrity/ima/ima_api.c index b37d043d5748..984e861f6e33 100644 --- a/security/integrity/ima/ima_api.c +++ b/security/integrity/ima/ima_api.c @@ -245,8 +245,10 @@ int ima_collect_measurement(struct ima_iint_cache *iint, struct file *file, const char *audit_cause = "failed"; struct inode *inode = file_inode(file); struct inode *real_inode = d_real_inode(file_dentry(file)); - const char *filename = file->f_path.dentry->d_name.name; struct ima_max_digest_data hash; + struct ima_digest_data *hash_hdr = container_of(&hash.hdr, + struct ima_digest_data, hdr); + struct name_snapshot filename; struct kstat stat; int result = 0; int length; @@ -286,9 +288,9 @@ int ima_collect_measurement(struct ima_iint_cache *iint, struct file *file, result = -ENODATA; } } else if (buf) { - result = ima_calc_buffer_hash(buf, size, &hash.hdr); + result = ima_calc_buffer_hash(buf, size, hash_hdr); } else { - result = ima_calc_file_hash(file, &hash.hdr); + result = ima_calc_file_hash(file, hash_hdr); } if (result && result != -EBADF && result != -EINVAL) @@ -303,11 +305,11 @@ int ima_collect_measurement(struct ima_iint_cache *iint, struct file *file, iint->ima_hash = tmpbuf; memcpy(iint->ima_hash, &hash, length); - iint->version = i_version; - if (real_inode != inode) { - iint->real_ino = real_inode->i_ino; - iint->real_dev = real_inode->i_sb->s_dev; - } + if (real_inode == inode) + iint->real_inode.version = i_version; + else + integrity_inode_attrs_store(&iint->real_inode, i_version, + real_inode); /* Possibly temporary failure due to type of read (eg. O_DIRECT) */ if (!result) @@ -317,9 +319,13 @@ out: if (file->f_flags & O_DIRECT) audit_cause = "failed(directio)"; + take_dentry_name_snapshot(&filename, file->f_path.dentry); + integrity_audit_msg(AUDIT_INTEGRITY_DATA, inode, - filename, "collect_data", audit_cause, - result, 0); + filename.name.name, "collect_data", + audit_cause, result, 0); + + release_dentry_name_snapshot(&filename); } return result; } @@ -432,6 +438,7 @@ out: */ const char *ima_d_path(const struct path *path, char **pathbuf, char *namebuf) { + struct name_snapshot filename; char *pathname = NULL; *pathbuf = __getname(); @@ -445,7 +452,10 @@ const char *ima_d_path(const struct path *path, char **pathbuf, char *namebuf) } if (!pathname) { - strscpy(namebuf, path->dentry->d_name.name, NAME_MAX); + take_dentry_name_snapshot(&filename, path->dentry); + strscpy(namebuf, filename.name.name, NAME_MAX); + release_dentry_name_snapshot(&filename); + pathname = namebuf; } diff --git a/security/integrity/ima/ima_appraise.c b/security/integrity/ima/ima_appraise.c index 3497741caea9..656c709b974f 100644 --- a/security/integrity/ima/ima_appraise.c +++ b/security/integrity/ima/ima_appraise.c @@ -378,7 +378,9 @@ static int xattr_verify(enum ima_hooks func, struct ima_iint_cache *iint, } rc = calc_file_id_hash(IMA_VERITY_DIGSIG, iint->ima_hash->algo, - iint->ima_hash->digest, &hash.hdr); + iint->ima_hash->digest, + container_of(&hash.hdr, + struct ima_digest_data, hdr)); if (rc) { *cause = "sigv3-hashing-error"; *status = INTEGRITY_FAIL; diff --git a/security/integrity/ima/ima_crypto.c b/security/integrity/ima/ima_crypto.c index f3738b2c8bcd..6f5696d999d0 100644 --- a/security/integrity/ima/ima_crypto.c +++ b/security/integrity/ima/ima_crypto.c @@ -57,11 +57,6 @@ MODULE_PARM_DESC(ahash_bufsize, "Maximum ahash buffer size"); static struct crypto_shash *ima_shash_tfm; static struct crypto_ahash *ima_ahash_tfm; -struct ima_algo_desc { - struct crypto_shash *tfm; - enum hash_algo algo; -}; - int ima_sha1_idx __ro_after_init; int ima_hash_algo_idx __ro_after_init; /* @@ -70,7 +65,7 @@ int ima_hash_algo_idx __ro_after_init; */ int ima_extra_slots __ro_after_init; -static struct ima_algo_desc *ima_algo_array; +struct ima_algo_desc *ima_algo_array __ro_after_init; static int __init ima_init_ima_crypto(void) { diff --git a/security/integrity/ima/ima_fs.c b/security/integrity/ima/ima_fs.c index cd1683dad3bf..abdd22007ed8 100644 --- a/security/integrity/ima/ima_fs.c +++ b/security/integrity/ima/ima_fs.c @@ -116,9 +116,31 @@ void ima_putc(struct seq_file *m, void *data, int datalen) seq_putc(m, *(char *)data++); } +static struct dentry **ascii_securityfs_measurement_lists __ro_after_init; +static struct dentry **binary_securityfs_measurement_lists __ro_after_init; +static int securityfs_measurement_list_count __ro_after_init; + +static void lookup_template_data_hash_algo(int *algo_idx, enum hash_algo *algo, + struct seq_file *m, + struct dentry **lists) +{ + struct dentry *dentry; + int i; + + dentry = file_dentry(m->file); + + for (i = 0; i < securityfs_measurement_list_count; i++) { + if (dentry == lists[i]) { + *algo_idx = i; + *algo = ima_algo_array[i].algo; + break; + } + } +} + /* print format: * 32bit-le=pcr# - * char[20]=template digest + * char[n]=template digest * 32bit-le=template name size * char[n]=template name * [eventdata length] @@ -132,7 +154,15 @@ int ima_measurements_show(struct seq_file *m, void *v) char *template_name; u32 pcr, namelen, template_data_len; /* temporary fields */ bool is_ima_template = false; - int i; + enum hash_algo algo; + int i, algo_idx; + + algo_idx = ima_sha1_idx; + algo = HASH_ALGO_SHA1; + + if (m->file != NULL) + lookup_template_data_hash_algo(&algo_idx, &algo, m, + binary_securityfs_measurement_lists); /* get entry */ e = qe->entry; @@ -151,7 +181,7 @@ int ima_measurements_show(struct seq_file *m, void *v) ima_putc(m, &pcr, sizeof(e->pcr)); /* 2nd: template digest */ - ima_putc(m, e->digests[ima_sha1_idx].digest, TPM_DIGEST_SIZE); + ima_putc(m, e->digests[algo_idx].digest, hash_digest_size[algo]); /* 3rd: template name size */ namelen = !ima_canonical_fmt ? strlen(template_name) : @@ -220,7 +250,15 @@ static int ima_ascii_measurements_show(struct seq_file *m, void *v) struct ima_queue_entry *qe = v; struct ima_template_entry *e; char *template_name; - int i; + enum hash_algo algo; + int i, algo_idx; + + algo_idx = ima_sha1_idx; + algo = HASH_ALGO_SHA1; + + if (m->file != NULL) + lookup_template_data_hash_algo(&algo_idx, &algo, m, + ascii_securityfs_measurement_lists); /* get entry */ e = qe->entry; @@ -233,8 +271,8 @@ static int ima_ascii_measurements_show(struct seq_file *m, void *v) /* 1st: PCR used (config option) */ seq_printf(m, "%2d ", e->pcr); - /* 2nd: SHA1 template hash */ - ima_print_digest(m, e->digests[ima_sha1_idx].digest, TPM_DIGEST_SIZE); + /* 2nd: template hash */ + ima_print_digest(m, e->digests[algo_idx].digest, hash_digest_size[algo]); /* 3th: template name */ seq_printf(m, " %s", template_name); @@ -379,6 +417,71 @@ static const struct seq_operations ima_policy_seqops = { }; #endif +static void __init remove_securityfs_measurement_lists(struct dentry **lists) +{ + int i; + + if (lists) { + for (i = 0; i < securityfs_measurement_list_count; i++) + securityfs_remove(lists[i]); + + kfree(lists); + } + + securityfs_measurement_list_count = 0; +} + +static int __init create_securityfs_measurement_lists(void) +{ + char file_name[NAME_MAX + 1]; + struct dentry *dentry; + u16 algo; + int i; + + securityfs_measurement_list_count = NR_BANKS(ima_tpm_chip); + + if (ima_sha1_idx >= NR_BANKS(ima_tpm_chip)) + securityfs_measurement_list_count++; + + ascii_securityfs_measurement_lists = + kcalloc(securityfs_measurement_list_count, sizeof(struct dentry *), + GFP_KERNEL); + if (!ascii_securityfs_measurement_lists) + return -ENOMEM; + + binary_securityfs_measurement_lists = + kcalloc(securityfs_measurement_list_count, sizeof(struct dentry *), + GFP_KERNEL); + if (!binary_securityfs_measurement_lists) + return -ENOMEM; + + for (i = 0; i < securityfs_measurement_list_count; i++) { + algo = ima_algo_array[i].algo; + + sprintf(file_name, "ascii_runtime_measurements_%s", + hash_algo_name[algo]); + dentry = securityfs_create_file(file_name, S_IRUSR | S_IRGRP, + ima_dir, NULL, + &ima_ascii_measurements_ops); + if (IS_ERR(dentry)) + return PTR_ERR(dentry); + + ascii_securityfs_measurement_lists[i] = dentry; + + sprintf(file_name, "binary_runtime_measurements_%s", + hash_algo_name[algo]); + dentry = securityfs_create_file(file_name, S_IRUSR | S_IRGRP, + ima_dir, NULL, + &ima_measurements_ops); + if (IS_ERR(dentry)) + return PTR_ERR(dentry); + + binary_securityfs_measurement_lists[i] = dentry; + } + + return 0; +} + /* * ima_open_policy: sequentialize access to the policy file */ @@ -454,6 +557,9 @@ int __init ima_fs_init(void) { int ret; + ascii_securityfs_measurement_lists = NULL; + binary_securityfs_measurement_lists = NULL; + ima_dir = securityfs_create_dir("ima", integrity_dir); if (IS_ERR(ima_dir)) return PTR_ERR(ima_dir); @@ -465,19 +571,21 @@ int __init ima_fs_init(void) goto out; } + ret = create_securityfs_measurement_lists(); + if (ret != 0) + goto out; + binary_runtime_measurements = - securityfs_create_file("binary_runtime_measurements", - S_IRUSR | S_IRGRP, ima_dir, NULL, - &ima_measurements_ops); + securityfs_create_symlink("binary_runtime_measurements", ima_dir, + "binary_runtime_measurements_sha1", NULL); if (IS_ERR(binary_runtime_measurements)) { ret = PTR_ERR(binary_runtime_measurements); goto out; } ascii_runtime_measurements = - securityfs_create_file("ascii_runtime_measurements", - S_IRUSR | S_IRGRP, ima_dir, NULL, - &ima_ascii_measurements_ops); + securityfs_create_symlink("ascii_runtime_measurements", ima_dir, + "ascii_runtime_measurements_sha1", NULL); if (IS_ERR(ascii_runtime_measurements)) { ret = PTR_ERR(ascii_runtime_measurements); goto out; @@ -515,6 +623,8 @@ out: securityfs_remove(runtime_measurements_count); securityfs_remove(ascii_runtime_measurements); securityfs_remove(binary_runtime_measurements); + remove_securityfs_measurement_lists(ascii_securityfs_measurement_lists); + remove_securityfs_measurement_lists(binary_securityfs_measurement_lists); securityfs_remove(ima_symlink); securityfs_remove(ima_dir); diff --git a/security/integrity/ima/ima_iint.c b/security/integrity/ima/ima_iint.c index e7c9c216c1c6..e23412a2c56b 100644 --- a/security/integrity/ima/ima_iint.c +++ b/security/integrity/ima/ima_iint.c @@ -59,7 +59,7 @@ static void ima_iint_init_always(struct ima_iint_cache *iint, struct inode *inode) { iint->ima_hash = NULL; - iint->version = 0; + iint->real_inode.version = 0; iint->flags = 0UL; iint->atomic_flags = 0UL; iint->ima_file_status = INTEGRITY_UNKNOWN; diff --git a/security/integrity/ima/ima_init.c b/security/integrity/ima/ima_init.c index 393f5c7912d5..4e208239a40e 100644 --- a/security/integrity/ima/ima_init.c +++ b/security/integrity/ima/ima_init.c @@ -48,12 +48,14 @@ static int __init ima_add_boot_aggregate(void) struct ima_event_data event_data = { .iint = iint, .filename = boot_aggregate_name }; struct ima_max_digest_data hash; + struct ima_digest_data *hash_hdr = container_of(&hash.hdr, + struct ima_digest_data, hdr); int result = -ENOMEM; int violation = 0; memset(iint, 0, sizeof(*iint)); memset(&hash, 0, sizeof(hash)); - iint->ima_hash = &hash.hdr; + iint->ima_hash = hash_hdr; iint->ima_hash->algo = ima_hash_algo; iint->ima_hash->length = hash_digest_size[ima_hash_algo]; @@ -70,7 +72,7 @@ static int __init ima_add_boot_aggregate(void) * is not found. */ if (ima_tpm_chip) { - result = ima_calc_boot_aggregate(&hash.hdr); + result = ima_calc_boot_aggregate(hash_hdr); if (result < 0) { audit_cause = "hashing_error"; goto err_out; diff --git a/security/integrity/ima/ima_kexec.c b/security/integrity/ima/ima_kexec.c index dadc1d138118..52e00332defe 100644 --- a/security/integrity/ima/ima_kexec.c +++ b/security/integrity/ima/ima_kexec.c @@ -30,6 +30,7 @@ static int ima_dump_measurement_list(unsigned long *buffer_size, void **buffer, goto out; } + file.file = NULL; file.size = segment_size; file.read_pos = 0; file.count = sizeof(khdr); /* reserved space */ diff --git a/security/integrity/ima/ima_main.c b/security/integrity/ima/ima_main.c index c84e8c55333d..f04f43af651c 100644 --- a/security/integrity/ima/ima_main.c +++ b/security/integrity/ima/ima_main.c @@ -26,6 +26,7 @@ #include <linux/ima.h> #include <linux/fs.h> #include <linux/iversion.h> +#include <linux/evm.h> #include "ima.h" @@ -173,7 +174,7 @@ static void ima_check_last_writer(struct ima_iint_cache *iint, STATX_CHANGE_COOKIE, AT_STATX_SYNC_AS_STAT) || !(stat.result_mask & STATX_CHANGE_COOKIE) || - stat.change_cookie != iint->version) { + stat.change_cookie != iint->real_inode.version) { iint->flags &= ~(IMA_DONE_MASK | IMA_NEW_FILE); iint->measured_pcrs = 0; if (update) @@ -208,9 +209,10 @@ static int process_measurement(struct file *file, const struct cred *cred, u32 secid, char *buf, loff_t size, int mask, enum ima_hooks func) { - struct inode *backing_inode, *inode = file_inode(file); + struct inode *real_inode, *inode = file_inode(file); struct ima_iint_cache *iint = NULL; struct ima_template_desc *template_desc = NULL; + struct inode *metadata_inode; char *pathbuf = NULL; char filename[NAME_MAX]; const char *pathname = NULL; @@ -285,17 +287,28 @@ static int process_measurement(struct file *file, const struct cred *cred, iint->measured_pcrs = 0; } - /* Detect and re-evaluate changes made to the backing file. */ - backing_inode = d_real_inode(file_dentry(file)); - if (backing_inode != inode && + /* + * On stacked filesystems, detect and re-evaluate file data and + * metadata changes. + */ + real_inode = d_real_inode(file_dentry(file)); + if (real_inode != inode && (action & IMA_DO_MASK) && (iint->flags & IMA_DONE_MASK)) { - if (!IS_I_VERSION(backing_inode) || - backing_inode->i_sb->s_dev != iint->real_dev || - backing_inode->i_ino != iint->real_ino || - !inode_eq_iversion(backing_inode, iint->version)) { + if (!IS_I_VERSION(real_inode) || + integrity_inode_attrs_changed(&iint->real_inode, + real_inode)) { iint->flags &= ~IMA_DONE_MASK; iint->measured_pcrs = 0; } + + /* + * Reset the EVM status when metadata changed. + */ + metadata_inode = d_inode(d_real(file_dentry(file), + D_REAL_METADATA)); + if (evm_metadata_changed(inode, metadata_inode)) + iint->flags &= ~(IMA_APPRAISED | + IMA_APPRAISED_SUBMASK); } /* Determine if already appraised/measured based on bitmask @@ -902,6 +915,13 @@ static int ima_post_load_data(char *buf, loff_t size, return 0; } + /* + * Measure the init_module syscall buffer containing the ELF image. + */ + if (load_id == LOADING_MODULE) + ima_measure_critical_data("modules", "init_module", + buf, size, true, NULL, 0); + return 0; } @@ -941,6 +961,8 @@ int process_buffer_measurement(struct mnt_idmap *idmap, .buf_len = size}; struct ima_template_desc *template; struct ima_max_digest_data hash; + struct ima_digest_data *hash_hdr = container_of(&hash.hdr, + struct ima_digest_data, hdr); char digest_hash[IMA_MAX_DIGEST_SIZE]; int digest_hash_len = hash_digest_size[ima_hash_algo]; int violation = 0; @@ -979,7 +1001,7 @@ int process_buffer_measurement(struct mnt_idmap *idmap, if (!pcr) pcr = CONFIG_IMA_MEASURE_PCR_IDX; - iint.ima_hash = &hash.hdr; + iint.ima_hash = hash_hdr; iint.ima_hash->algo = ima_hash_algo; iint.ima_hash->length = hash_digest_size[ima_hash_algo]; @@ -990,7 +1012,7 @@ int process_buffer_measurement(struct mnt_idmap *idmap, } if (buf_hash) { - memcpy(digest_hash, hash.hdr.digest, digest_hash_len); + memcpy(digest_hash, hash_hdr->digest, digest_hash_len); ret = ima_calc_buffer_hash(digest_hash, digest_hash_len, iint.ima_hash); diff --git a/security/integrity/ima/ima_template_lib.c b/security/integrity/ima/ima_template_lib.c index 6cd0add524cd..4183956c53af 100644 --- a/security/integrity/ima/ima_template_lib.c +++ b/security/integrity/ima/ima_template_lib.c @@ -339,6 +339,8 @@ int ima_eventdigest_init(struct ima_event_data *event_data, struct ima_field_data *field_data) { struct ima_max_digest_data hash; + struct ima_digest_data *hash_hdr = container_of(&hash.hdr, + struct ima_digest_data, hdr); u8 *cur_digest = NULL; u32 cur_digestsize = 0; struct inode *inode; @@ -358,7 +360,7 @@ int ima_eventdigest_init(struct ima_event_data *event_data, if ((const char *)event_data->filename == boot_aggregate_name) { if (ima_tpm_chip) { hash.hdr.algo = HASH_ALGO_SHA1; - result = ima_calc_boot_aggregate(&hash.hdr); + result = ima_calc_boot_aggregate(hash_hdr); /* algo can change depending on available PCR banks */ if (!result && hash.hdr.algo != HASH_ALGO_SHA1) @@ -368,7 +370,7 @@ int ima_eventdigest_init(struct ima_event_data *event_data, memset(&hash, 0, sizeof(hash)); } - cur_digest = hash.hdr.digest; + cur_digest = hash_hdr->digest; cur_digestsize = hash_digest_size[HASH_ALGO_SHA1]; goto out; } @@ -379,14 +381,14 @@ int ima_eventdigest_init(struct ima_event_data *event_data, inode = file_inode(event_data->file); hash.hdr.algo = ima_template_hash_algo_allowed(ima_hash_algo) ? ima_hash_algo : HASH_ALGO_SHA1; - result = ima_calc_file_hash(event_data->file, &hash.hdr); + result = ima_calc_file_hash(event_data->file, hash_hdr); if (result) { integrity_audit_msg(AUDIT_INTEGRITY_DATA, inode, event_data->filename, "collect_data", "failed", result, 0); return result; } - cur_digest = hash.hdr.digest; + cur_digest = hash_hdr->digest; cur_digestsize = hash.hdr.length; out: return ima_eventdigest_init_common(cur_digest, cur_digestsize, @@ -483,7 +485,10 @@ static int ima_eventname_init_common(struct ima_event_data *event_data, bool size_limit) { const char *cur_filename = NULL; + struct name_snapshot filename; u32 cur_filename_len = 0; + bool snapshot = false; + int ret; BUG_ON(event_data->filename == NULL && event_data->file == NULL); @@ -496,7 +501,10 @@ static int ima_eventname_init_common(struct ima_event_data *event_data, } if (event_data->file) { - cur_filename = event_data->file->f_path.dentry->d_name.name; + take_dentry_name_snapshot(&filename, + event_data->file->f_path.dentry); + snapshot = true; + cur_filename = filename.name.name; cur_filename_len = strlen(cur_filename); } else /* @@ -505,8 +513,13 @@ static int ima_eventname_init_common(struct ima_event_data *event_data, */ cur_filename_len = IMA_EVENT_NAME_LEN_MAX; out: - return ima_write_template_field_data(cur_filename, cur_filename_len, - DATA_FMT_STRING, field_data); + ret = ima_write_template_field_data(cur_filename, cur_filename_len, + DATA_FMT_STRING, field_data); + + if (snapshot) + release_dentry_name_snapshot(&filename); + + return ret; } /* diff --git a/security/integrity/integrity.h b/security/integrity/integrity.h index 50d6f798e613..660f76cb69d3 100644 --- a/security/integrity/integrity.h +++ b/security/integrity/integrity.h @@ -31,19 +31,24 @@ enum evm_ima_xattr_type { }; struct evm_ima_xattr_data { - u8 type; + /* New members must be added within the __struct_group() macro below. */ + __struct_group(evm_ima_xattr_data_hdr, hdr, __packed, + u8 type; + ); u8 data[]; } __packed; /* Only used in the EVM HMAC code. */ struct evm_xattr { - struct evm_ima_xattr_data data; + struct evm_ima_xattr_data_hdr data; u8 digest[SHA1_DIGEST_SIZE]; } __packed; #define IMA_MAX_DIGEST_SIZE HASH_MAX_DIGESTSIZE struct ima_digest_data { + /* New members must be added within the __struct_group() macro below. */ + __struct_group(ima_digest_data_hdr, hdr, __packed, u8 algo; u8 length; union { @@ -57,6 +62,7 @@ struct ima_digest_data { } ng; u8 data[2]; } xattr; + ); u8 digest[]; } __packed; @@ -65,7 +71,7 @@ struct ima_digest_data { * with the maximum hash size, define ima_max_digest_data struct. */ struct ima_max_digest_data { - struct ima_digest_data hdr; + struct ima_digest_data_hdr hdr; u8 digest[HASH_MAX_DIGESTSIZE]; } __packed; diff --git a/security/security.c b/security/security.c index 0a9a0ac3f266..e5da848c50b9 100644 --- a/security/security.c +++ b/security/security.c @@ -2628,6 +2628,7 @@ EXPORT_SYMBOL(security_inode_copy_up); /** * security_inode_copy_up_xattr() - Filter xattrs in an overlayfs copy-up op + * @src: union dentry of copy-up file * @name: xattr name * * Filter the xattrs being copied up when a unioned file is copied up from a @@ -2638,7 +2639,7 @@ EXPORT_SYMBOL(security_inode_copy_up); * if the security module does not know about attribute, or a negative * error code to abort the copy up. */ -int security_inode_copy_up_xattr(const char *name) +int security_inode_copy_up_xattr(struct dentry *src, const char *name) { int rc; @@ -2647,7 +2648,7 @@ int security_inode_copy_up_xattr(const char *name) * xattr), -EOPNOTSUPP if it does not know anything about the xattr or * any other error code in case of an error. */ - rc = call_int_hook(inode_copy_up_xattr, name); + rc = call_int_hook(inode_copy_up_xattr, src, name); if (rc != LSM_RET_DEFAULT(inode_copy_up_xattr)) return rc; diff --git a/security/selinux/hooks.c b/security/selinux/hooks.c index e92061019bea..7eed331e90f0 100644 --- a/security/selinux/hooks.c +++ b/security/selinux/hooks.c @@ -3526,7 +3526,7 @@ static int selinux_inode_copy_up(struct dentry *src, struct cred **new) return 0; } -static int selinux_inode_copy_up_xattr(const char *name) +static int selinux_inode_copy_up_xattr(struct dentry *dentry, const char *name) { /* The copy_up hook above sets the initial context on an inode, but we * don't then want to overwrite it by blindly copying all the lower diff --git a/security/smack/smack_lsm.c b/security/smack/smack_lsm.c index efeac8365ad0..70ba2841e181 100644 --- a/security/smack/smack_lsm.c +++ b/security/smack/smack_lsm.c @@ -4886,7 +4886,7 @@ static int smack_inode_copy_up(struct dentry *dentry, struct cred **new) return 0; } -static int smack_inode_copy_up_xattr(const char *name) +static int smack_inode_copy_up_xattr(struct dentry *src, const char *name) { /* * Return 1 if this is the smack access Smack attribute. |