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 +#include 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/security/integrity/ima/ima.h b/security/integrity/ima/ima.h index 11d7c0332207..9151b5369cdc 100644 --- a/security/integrity/ima/ima.h +++ b/security/integrity/ima/ima.h @@ -175,12 +175,10 @@ 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 3d286de231e1..984e861f6e33 100644 --- a/security/integrity/ima/ima_api.c +++ b/security/integrity/ima/ima_api.c @@ -305,11 +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) 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_main.c b/security/integrity/ima/ima_main.c index eebf629f192e..4b215d85c14b 100644 --- a/security/integrity/ima/ima_main.c +++ b/security/integrity/ima/ima_main.c @@ -173,7 +173,7 @@ 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) @@ -292,9 +292,8 @@ static int process_measurement(struct file *file, const struct cred *cred, if (real_inode != inode && (action & IMA_DO_MASK) && (iint->flags & IMA_DONE_MASK)) { if (!IS_I_VERSION(real_inode) || - real_inode->i_sb->s_dev != iint->real_dev || - real_inode->i_ino != iint->real_ino || - !inode_eq_iversion(real_inode, iint->version)) { + integrity_inode_attrs_changed(&iint->real_inode, + real_inode)) { iint->flags &= ~IMA_DONE_MASK; iint->measured_pcrs = 0; }