[PATCH v4 14/23] IMA: Change internal interfaces to use lsmblobs
Kees Cook
keescook at chromium.org
Wed Jun 26 23:09:40 UTC 2019
On Wed, Jun 26, 2019 at 12:22:25PM -0700, Casey Schaufler wrote:
> The IMA interfaces ima_get_action() and ima_match_policy()
> call LSM functions that use lsmblobs. Change the IMA functions
> to pass the lsmblob to be compatible with the LSM functions.
>
> Signed-off-by: Casey Schaufler <casey at schaufler-ca.com>
Reviewed-by: Kees Cook <keescook at chromium.org>
-Kees
> ---
> security/integrity/ima/ima.h | 10 ++++++----
> security/integrity/ima/ima_api.c | 9 +++++----
> security/integrity/ima/ima_appraise.c | 4 +---
> security/integrity/ima/ima_main.c | 27 +++++++++++----------------
> security/integrity/ima/ima_policy.c | 12 ++++++------
> 5 files changed, 29 insertions(+), 33 deletions(-)
>
> diff --git a/security/integrity/ima/ima.h b/security/integrity/ima/ima.h
> index 5a337239d9e4..73b3b15dec5c 100644
> --- a/security/integrity/ima/ima.h
> +++ b/security/integrity/ima/ima.h
> @@ -192,8 +192,9 @@ enum ima_hooks {
> };
>
> /* LIM API function definitions */
> -int ima_get_action(struct inode *inode, const struct cred *cred, u32 secid,
> - int mask, enum ima_hooks func, int *pcr);
> +int ima_get_action(struct inode *inode, const struct cred *cred,
> + struct lsmblob *blob, int mask, enum ima_hooks func,
> + int *pcr);
> int ima_must_measure(struct inode *inode, int mask, enum ima_hooks func);
> int ima_collect_measurement(struct integrity_iint_cache *iint,
> struct file *file, void *buf, loff_t size,
> @@ -213,8 +214,9 @@ void ima_free_template_entry(struct ima_template_entry *entry);
> const char *ima_d_path(const struct path *path, char **pathbuf, char *filename);
>
> /* IMA policy related functions */
> -int ima_match_policy(struct inode *inode, const struct cred *cred, u32 secid,
> - enum ima_hooks func, int mask, int flags, int *pcr);
> +int ima_match_policy(struct inode *inode, const struct cred *cred,
> + struct lsmblob *blob, enum ima_hooks func, int mask,
> + int flags, int *pcr);
> void ima_init_policy(void);
> void ima_update_policy(void);
> void ima_update_policy_flag(void);
> diff --git a/security/integrity/ima/ima_api.c b/security/integrity/ima/ima_api.c
> index c7505fb122d4..94b2a4840d81 100644
> --- a/security/integrity/ima/ima_api.c
> +++ b/security/integrity/ima/ima_api.c
> @@ -159,7 +159,7 @@ void ima_add_violation(struct file *file, const unsigned char *filename,
> * ima_get_action - appraise & measure decision based on policy.
> * @inode: pointer to inode to measure
> * @cred: pointer to credentials structure to validate
> - * @secid: secid of the task being validated
> + * @blob: LSM data of the task being validated
> * @mask: contains the permission mask (MAY_READ, MAY_WRITE, MAY_EXEC,
> * MAY_APPEND)
> * @func: caller identifier
> @@ -175,14 +175,15 @@ void ima_add_violation(struct file *file, const unsigned char *filename,
> * Returns IMA_MEASURE, IMA_APPRAISE mask.
> *
> */
> -int ima_get_action(struct inode *inode, const struct cred *cred, u32 secid,
> - int mask, enum ima_hooks func, int *pcr)
> +int ima_get_action(struct inode *inode, const struct cred *cred,
> + struct lsmblob *blob, int mask, enum ima_hooks func,
> + int *pcr)
> {
> int flags = IMA_MEASURE | IMA_AUDIT | IMA_APPRAISE | IMA_HASH;
>
> flags &= ima_policy_flag;
>
> - return ima_match_policy(inode, cred, secid, func, mask, flags, pcr);
> + return ima_match_policy(inode, cred, blob, func, mask, flags, pcr);
> }
>
> /*
> diff --git a/security/integrity/ima/ima_appraise.c b/security/integrity/ima/ima_appraise.c
> index 85c7692fc4a3..3ff7aae81829 100644
> --- a/security/integrity/ima/ima_appraise.c
> +++ b/security/integrity/ima/ima_appraise.c
> @@ -50,15 +50,13 @@ bool is_ima_appraise_enabled(void)
> */
> int ima_must_appraise(struct inode *inode, int mask, enum ima_hooks func)
> {
> - u32 secid;
> struct lsmblob blob;
>
> if (!ima_appraise)
> return 0;
>
> security_task_getsecid(current, &blob);
> - lsmblob_secid(&blob, &secid);
> - return ima_match_policy(inode, current_cred(), secid, func, mask,
> + return ima_match_policy(inode, current_cred(), &blob, func, mask,
> IMA_APPRAISE | IMA_HASH, NULL);
> }
>
> diff --git a/security/integrity/ima/ima_main.c b/security/integrity/ima/ima_main.c
> index 1afb75a893af..0588dd9a88db 100644
> --- a/security/integrity/ima/ima_main.c
> +++ b/security/integrity/ima/ima_main.c
> @@ -169,8 +169,8 @@ void ima_file_free(struct file *file)
> }
>
> 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 lsmblob *blob, char *buf, loff_t size,
> + int mask, enum ima_hooks func)
> {
> struct inode *inode = file_inode(file);
> struct integrity_iint_cache *iint = NULL;
> @@ -192,7 +192,7 @@ static int process_measurement(struct file *file, const struct cred *cred,
> * bitmask based on the appraise/audit/measurement policy.
> * Included is the appraise submask.
> */
> - action = ima_get_action(inode, cred, secid, mask, func, &pcr);
> + action = ima_get_action(inode, cred, blob, mask, func, &pcr);
> violation_check = ((func == FILE_CHECK || func == MMAP_CHECK) &&
> (ima_policy_flag & IMA_MEASURE));
> if (!action && !violation_check)
> @@ -339,8 +339,7 @@ int ima_file_mmap(struct file *file, unsigned long prot)
>
> if (file && (prot & PROT_EXEC)) {
> security_task_getsecid(current, &blob);
> - /* scaffolding - until process_measurement changes */
> - return process_measurement(file, current_cred(), blob.secid[0],
> + return process_measurement(file, current_cred(), &blob,
> NULL, 0, MAY_EXEC, MMAP_CHECK);
> }
>
> @@ -366,16 +365,14 @@ int ima_bprm_check(struct linux_binprm *bprm)
> struct lsmblob blob;
>
> security_task_getsecid(current, &blob);
> - /* scaffolding until process_measurement changes */
> - ret = process_measurement(bprm->file, current_cred(), blob.secid[0],
> - NULL, 0, MAY_EXEC, BPRM_CHECK);
> + ret = process_measurement(bprm->file, current_cred(), &blob, NULL, 0,
> + MAY_EXEC, BPRM_CHECK);
> if (ret)
> return ret;
>
> security_cred_getsecid(bprm->cred, &blob);
> - /* scaffolding until process_measurement changes */
> - return process_measurement(bprm->file, bprm->cred, blob.secid[0],
> - NULL, 0, MAY_EXEC, CREDS_CHECK);
> + return process_measurement(bprm->file, bprm->cred, &blob, NULL, 0,
> + MAY_EXEC, CREDS_CHECK);
> }
>
> /**
> @@ -393,8 +390,7 @@ int ima_file_check(struct file *file, int mask)
> struct lsmblob blob;
>
> security_task_getsecid(current, &blob);
> - /* scaffolding until process_measurement changes */
> - return process_measurement(file, current_cred(), blob.secid[0], NULL, 0,
> + return process_measurement(file, current_cred(), &blob, NULL, 0,
> mask & (MAY_READ | MAY_WRITE | MAY_EXEC |
> MAY_APPEND), FILE_CHECK);
> }
> @@ -526,9 +522,8 @@ int ima_post_read_file(struct file *file, void *buf, loff_t size,
>
> func = read_idmap[read_id] ?: FILE_CHECK;
> security_task_getsecid(current, &blob);
> - /* scaffolding until process_measurement changes */
> - return process_measurement(file, current_cred(), blob.secid[0], buf,
> - size, MAY_READ, func);
> + return process_measurement(file, current_cred(), &blob, buf, size,
> + MAY_READ, func);
> }
>
> /**
> diff --git a/security/integrity/ima/ima_policy.c b/security/integrity/ima/ima_policy.c
> index 92ee3d984c73..dbad256aa7b4 100644
> --- a/security/integrity/ima/ima_policy.c
> +++ b/security/integrity/ima/ima_policy.c
> @@ -286,7 +286,7 @@ static void ima_lsm_update_rules(void)
> * Returns true on rule match, false on failure.
> */
> static bool ima_match_rules(struct ima_rule_entry *rule, struct inode *inode,
> - const struct cred *cred, u32 secid,
> + const struct cred *cred, struct lsmblob *blob,
> enum ima_hooks func, int mask)
> {
> int i;
> @@ -345,7 +345,6 @@ static bool ima_match_rules(struct ima_rule_entry *rule, struct inode *inode,
> case LSM_SUBJ_USER:
> case LSM_SUBJ_ROLE:
> case LSM_SUBJ_TYPE:
> - lsmblob_init(&blob, secid);
> rc = security_filter_rule_match(&blob,
> rule->lsm[i].type,
> Audit_equal,
> @@ -394,7 +393,7 @@ static int get_subaction(struct ima_rule_entry *rule, enum ima_hooks func)
> * @inode: pointer to an inode for which the policy decision is being made
> * @cred: pointer to a credentials structure for which the policy decision is
> * being made
> - * @secid: LSM secid of the task to be validated
> + * @blob: LSM data of the task to be validated
> * @func: IMA hook identifier
> * @mask: requested action (MAY_READ | MAY_WRITE | MAY_APPEND | MAY_EXEC)
> * @pcr: set the pcr to extend
> @@ -406,8 +405,9 @@ static int get_subaction(struct ima_rule_entry *rule, enum ima_hooks func)
> * list when walking it. Reads are many orders of magnitude more numerous
> * than writes so ima_match_policy() is classical RCU candidate.
> */
> -int ima_match_policy(struct inode *inode, const struct cred *cred, u32 secid,
> - enum ima_hooks func, int mask, int flags, int *pcr)
> +int ima_match_policy(struct inode *inode, const struct cred *cred,
> + struct lsmblob *blob, enum ima_hooks func, int mask,
> + int flags, int *pcr)
> {
> struct ima_rule_entry *entry;
> int action = 0, actmask = flags | (flags << 1);
> @@ -418,7 +418,7 @@ int ima_match_policy(struct inode *inode, const struct cred *cred, u32 secid,
> if (!(entry->action & actmask))
> continue;
>
> - if (!ima_match_rules(entry, inode, cred, secid, func, mask))
> + if (!ima_match_rules(entry, inode, cred, blob, func, mask))
> continue;
>
> action |= entry->flags & IMA_ACTION_FLAGS;
> --
> 2.20.1
>
--
Kees Cook
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