[PATCH v12 12/25] IMA: Change internal interfaces to use lsmblobs

Stephen Smalley sds at tycho.nsa.gov
Tue Dec 17 18:26:06 UTC 2019


On 12/16/19 5:36 PM, 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.
> 
> Reviewed-by: Kees Cook <keescook at chromium.org>
> Reviewed-by: John Johansen <john.johansen at canonical.com>
> Signed-off-by: Casey Schaufler <casey at schaufler-ca.com>
> cc: linux-integrity at vger.kernel.org

Needs an ack from linux-integrity, but for me:
Acked-by: Stephen Smalley <sds at tycho.nsa.gov>

> ---
>   security/integrity/ima/ima.h          | 11 ++++-----
>   security/integrity/ima/ima_api.c      | 10 ++++-----
>   security/integrity/ima/ima_appraise.c |  4 +---
>   security/integrity/ima/ima_main.c     | 32 +++++++++++----------------
>   security/integrity/ima/ima_policy.c   | 12 +++++-----
>   5 files changed, 31 insertions(+), 38 deletions(-)
> 
> diff --git a/security/integrity/ima/ima.h b/security/integrity/ima/ima.h
> index d95b0ece7434..96b6662ea39f 100644
> --- a/security/integrity/ima/ima.h
> +++ b/security/integrity/ima/ima.h
> @@ -205,9 +205,9 @@ extern const char *const func_tokens[];
>   struct modsig;
>   
>   /* 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,
> -		   struct ima_template_desc **template_desc);
> +int ima_get_action(struct inode *inode, const struct cred *cred,
> +		   struct lsmblob *blob, int mask, enum ima_hooks func,
> +		   int *pcr, struct ima_template_desc **template_desc);
>   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,
> @@ -232,8 +232,9 @@ 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,
>   		     struct ima_template_desc **template_desc);
>   void ima_init_policy(void);
>   void ima_update_policy(void);
> diff --git a/security/integrity/ima/ima_api.c b/security/integrity/ima/ima_api.c
> index 610759fe63b8..1ab769fa7df6 100644
> --- a/security/integrity/ima/ima_api.c
> +++ b/security/integrity/ima/ima_api.c
> @@ -163,7 +163,7 @@ 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
> @@ -181,15 +181,15 @@ 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,
> -		   struct ima_template_desc **template_desc)
> +int ima_get_action(struct inode *inode, const struct cred *cred,
> +		   struct lsmblob *blob, int mask, enum ima_hooks func,
> +		   int *pcr, struct ima_template_desc **template_desc)
>   {
>   	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,
>   				template_desc);
>   }
>   
> diff --git a/security/integrity/ima/ima_appraise.c b/security/integrity/ima/ima_appraise.c
> index 69e549164949..01c755a242ac 100644
> --- a/security/integrity/ima/ima_appraise.c
> +++ b/security/integrity/ima/ima_appraise.c
> @@ -48,15 +48,13 @@ 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, NULL);
>   }
>   
> diff --git a/security/integrity/ima/ima_main.c b/security/integrity/ima/ima_main.c
> index c8e3e234d446..86cc1419587e 100644
> --- a/security/integrity/ima/ima_main.c
> +++ b/security/integrity/ima/ima_main.c
> @@ -190,8 +190,8 @@ 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;
> @@ -214,7 +214,7 @@ 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,
>   				&template_desc);
>   	violation_check = ((func == FILE_CHECK || func == MMAP_CHECK) &&
>   			   (ima_policy_flag & IMA_MEASURE));
> @@ -388,8 +388,7 @@ 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);
>   	}
>   
> @@ -415,16 +414,14 @@ 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);
>   }
>   
>   /**
> @@ -442,8 +439,7 @@ 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);
>   }
> @@ -575,9 +571,8 @@ 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);
>   }
>   
>   /**
> @@ -669,9 +664,8 @@ void process_buffer_measurement(const void *buf, int size,
>   	 */
>   	if (func) {
>   		security_task_getsecid(current, &blob);
> -		/* scaffolding */
> -		action = ima_get_action(NULL, current_cred(), blob.secid[0],
> -					0, func, &pcr, &template);
> +		action = ima_get_action(NULL, current_cred(), &blob, 0, func,
> +					&pcr, &template);
>   		if (!(action & IMA_MEASURE))
>   			return;
>   	}
> diff --git a/security/integrity/ima/ima_policy.c b/security/integrity/ima/ima_policy.c
> index c7d2ea47a326..b089d4a8b27b 100644
> --- a/security/integrity/ima/ima_policy.c
> +++ b/security/integrity/ima/ima_policy.c
> @@ -368,7 +368,7 @@ int ima_lsm_policy_change(struct notifier_block *nb, unsigned long event,
>    * 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;
> @@ -431,7 +431,6 @@ 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,
> @@ -475,7 +474,7 @@ 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
> @@ -488,8 +487,9 @@ 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_template_desc **template_desc)
>   {
>   	struct ima_rule_entry *entry;
> @@ -504,7 +504,7 @@ 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;
> 



More information about the Linux-security-module-archive mailing list