From: Mehmet Kayaalp <mkayaalp@xxxxxxxxxxxxxxxxxx> The iint cache stores whether the file is measured, appraised, audited etc. This patch moves the IMA_AUDITED flag into the per-namespace ns_status, enabling IMA audit mechanism to audit the same file each time it is accessed in a new namespace. The ns_status is not looked up if the CONFIG_IMA_NS is disabled or if any of the IMA_NS_STATUS_ACTIONS (currently only IMA_AUDIT) is not enabled. Read and write operations on the iint flags is replaced with function calls. For reading, iint_flags() returns the bitwise AND of iint->flags and ns_status->flags. The ns_status flags are masked with IMA_NS_STATUS_FLAGS (currently only IMA_AUDITED). Similarly set_iint_flags() only writes the masked portion to the ns_status flags, while the iint flags is set as before. The ns_status parameter added to ima_audit_measurement() is used with the above functions to query and set the ns_status flags. Signed-off-by: Mehmet Kayaalp <mkayaalp@xxxxxxxxxxxxxxxxxx> Changelog: v2: * fixed flag calculation in iint_flags() --- init/Kconfig | 3 +++ security/integrity/ima/ima.h | 23 ++++++++++++++++++++++- security/integrity/ima/ima_api.c | 8 +++++--- security/integrity/ima/ima_main.c | 24 +++++++++++++++++------- security/integrity/ima/ima_ns.c | 20 ++++++++++++++++++++ 5 files changed, 67 insertions(+), 11 deletions(-) diff --git a/init/Kconfig b/init/Kconfig index 598baf451a54..d8edd1c03de8 100644 --- a/init/Kconfig +++ b/init/Kconfig @@ -1250,6 +1250,9 @@ config IMA_NS Allow the creation of IMA namespaces for each user namespace. Namespaced IMA enables having IMA features work separately in each IMA namespace. + Currently, only the audit status flags are stored in the namespace, + which allows the same file to be audited each time it is accessed + in a new namespace. endif # NAMESPACES diff --git a/security/integrity/ima/ima.h b/security/integrity/ima/ima.h index 28896d256e36..dd06e16c4e1c 100644 --- a/security/integrity/ima/ima.h +++ b/security/integrity/ima/ima.h @@ -282,7 +282,8 @@ int process_buffer_measurement(struct user_namespace *mnt_userns, int pcr, const char *func_data, bool buf_hash, u8 *digest, size_t digest_len); void ima_audit_measurement(struct integrity_iint_cache *iint, - const unsigned char *filename); + const unsigned char *filename, + struct ns_status *status); int ima_alloc_init_template(struct ima_event_data *event_data, struct ima_template_entry **entry, struct ima_template_desc *template_desc); @@ -426,6 +427,9 @@ static inline void ima_free_modsig(struct modsig *modsig) } #endif /* CONFIG_IMA_APPRAISE_MODSIG */ +#define IMA_NS_STATUS_ACTIONS IMA_AUDIT +#define IMA_NS_STATUS_FLAGS IMA_AUDITED + int ima_ns_init(void); struct ima_namespace; int ima_init_namespace(struct ima_namespace *ns); @@ -436,6 +440,10 @@ struct ns_status *ima_get_ns_status(struct ima_namespace *ns, void free_ns_status_cache(struct ima_namespace *ns); +unsigned long iint_flags(struct integrity_iint_cache *iint, + struct ns_status *status); +unsigned long set_iint_flags(struct integrity_iint_cache *iint, + struct ns_status *status, unsigned long flags); #else static inline struct ns_status *ima_get_ns_status(struct ima_namespace *ns, @@ -444,6 +452,19 @@ static inline struct ns_status *ima_get_ns_status(struct ima_namespace *ns, return NULL; } +static inline unsigned long iint_flags(struct integrity_iint_cache *iint, + struct ns_status *status) +{ + return iint->flags; +} + +static inline unsigned long set_iint_flags(struct integrity_iint_cache *iint, + struct ns_status *status, + unsigned long flags) +{ + iint->flags = flags; + return flags; +} #endif /* CONFIG_IMA_NS */ /* LSM based policy rules require audit */ diff --git a/security/integrity/ima/ima_api.c b/security/integrity/ima/ima_api.c index a64fb0130b01..8f7bab17b784 100644 --- a/security/integrity/ima/ima_api.c +++ b/security/integrity/ima/ima_api.c @@ -342,14 +342,16 @@ void ima_store_measurement(struct integrity_iint_cache *iint, } void ima_audit_measurement(struct integrity_iint_cache *iint, - const unsigned char *filename) + const unsigned char *filename, + struct ns_status *status) { struct audit_buffer *ab; char *hash; const char *algo_name = hash_algo_name[iint->ima_hash->algo]; int i; + unsigned long flags = iint_flags(iint, status); - if (iint->flags & IMA_AUDITED) + if (flags & IMA_AUDITED) return; hash = kzalloc((iint->ima_hash->length * 2) + 1, GFP_KERNEL); @@ -372,7 +374,7 @@ void ima_audit_measurement(struct integrity_iint_cache *iint, audit_log_task_info(ab); audit_log_end(ab); - iint->flags |= IMA_AUDITED; + set_iint_flags(iint, status, flags | IMA_AUDITED); out: kfree(hash); return; diff --git a/security/integrity/ima/ima_main.c b/security/integrity/ima/ima_main.c index 465865412100..4df60dbb56f7 100644 --- a/security/integrity/ima/ima_main.c +++ b/security/integrity/ima/ima_main.c @@ -204,6 +204,7 @@ static int process_measurement(struct file *file, const struct cred *cred, { struct inode *inode = file_inode(file); struct integrity_iint_cache *iint = NULL; + struct ns_status *status = NULL; struct ima_template_desc *template_desc = NULL; char *pathbuf = NULL; char filename[NAME_MAX]; @@ -216,6 +217,7 @@ static int process_measurement(struct file *file, const struct cred *cred, bool violation_check; enum hash_algo hash_algo; unsigned int allowed_algos = 0; + unsigned long flags; if (!ima_policy_flag || !S_ISREG(inode->i_mode)) return 0; @@ -244,6 +246,12 @@ static int process_measurement(struct file *file, const struct cred *cred, iint = integrity_inode_get(inode); if (!iint) rc = -ENOMEM; + + if (!rc && (action & IMA_NS_STATUS_ACTIONS)) { + status = ima_get_ns_status(get_current_ns(), inode); + if (IS_ERR(status)) + rc = PTR_ERR(status); + } } if (!rc && violation_check) @@ -259,11 +267,13 @@ static int process_measurement(struct file *file, const struct cred *cred, mutex_lock(&iint->mutex); + flags = iint_flags(iint, status); + if (test_and_clear_bit(IMA_CHANGE_ATTR, &iint->atomic_flags)) /* reset appraisal flags if ima_inode_post_setattr was called */ - iint->flags &= ~(IMA_APPRAISE | IMA_APPRAISED | - IMA_APPRAISE_SUBMASK | IMA_APPRAISED_SUBMASK | - IMA_ACTION_FLAGS); + flags &= ~(IMA_APPRAISE | IMA_APPRAISED | + IMA_APPRAISE_SUBMASK | IMA_APPRAISED_SUBMASK | + IMA_ACTION_FLAGS); /* * Re-evaulate the file if either the xattr has changed or the @@ -274,7 +284,7 @@ static int process_measurement(struct file *file, const struct cred *cred, ((inode->i_sb->s_iflags & SB_I_IMA_UNVERIFIABLE_SIGNATURE) && !(inode->i_sb->s_iflags & SB_I_UNTRUSTED_MOUNTER) && !(action & IMA_FAIL_UNVERIFIABLE_SIGS))) { - iint->flags &= ~IMA_DONE_MASK; + flags &= ~IMA_DONE_MASK; iint->measured_pcrs = 0; } @@ -282,9 +292,9 @@ static int process_measurement(struct file *file, const struct cred *cred, * (IMA_MEASURE, IMA_MEASURED, IMA_XXXX_APPRAISE, IMA_XXXX_APPRAISED, * IMA_AUDIT, IMA_AUDITED) */ - iint->flags |= action; + flags = set_iint_flags(iint, status, flags | action); action &= IMA_DO_MASK; - action &= ~((iint->flags & (IMA_DONE_MASK ^ IMA_MEASURED)) >> 1); + action &= ~((flags & (IMA_DONE_MASK ^ IMA_MEASURED)) >> 1); /* If target pcr is already measured, unset IMA_MEASURE action */ if ((action & IMA_MEASURE) && (iint->measured_pcrs & (0x1 << pcr))) @@ -359,7 +369,7 @@ static int process_measurement(struct file *file, const struct cred *cred, &pathname, filename); } if (action & IMA_AUDIT) - ima_audit_measurement(iint, pathname); + ima_audit_measurement(iint, pathname, status); if ((file->f_flags & O_DIRECT) && (iint->flags & IMA_PERMIT_DIRECTIO)) rc = 0; diff --git a/security/integrity/ima/ima_ns.c b/security/integrity/ima/ima_ns.c index b10d92959033..1c23dc1b8100 100644 --- a/security/integrity/ima/ima_ns.c +++ b/security/integrity/ima/ima_ns.c @@ -75,6 +75,26 @@ void free_ima_ns(struct kref *kref) destroy_ima_ns(ns); } +unsigned long iint_flags(struct integrity_iint_cache *iint, + struct ns_status *status) +{ + if (!status) + return iint->flags; + + return (iint->flags & ~IMA_NS_STATUS_FLAGS) | + (status->flags & IMA_NS_STATUS_FLAGS); +} + +unsigned long set_iint_flags(struct integrity_iint_cache *iint, + struct ns_status *status, unsigned long flags) +{ + iint->flags = flags; + if (status) + status->flags = flags & IMA_NS_STATUS_FLAGS; + + return flags; +} + int __init imans_cache_init(void) { imans_cachep = KMEM_CACHE(ima_namespace, SLAB_PANIC); -- 2.31.1