IMA: support for per policy rule template formats

Admins may wish to log different measurements using different IMA
templates. Add support for overriding the default template on a per-rule
basis.

Inspired-by: Roberto Sassu <roberto.sassu@huawei.com>
Signed-off-by: Matthew Garrett <mjg59@google.com>
Signed-off-by: Mimi Zohar <zohar@linux.ibm.com>

1 files changed, 17 insertions, 7 deletions

diff --git a/security/integrity/ima/ima_api.c b/security/integrity/ima/ima_api.c
index 4aec6b035fe9..c0cf4bcfc82f 100644
--- a/security/integrity/ima/ima_api.c
+++ b/security/integrity/ima/ima_api.c
@@ -38,11 +38,17 @@ void ima_free_template_entry(struct ima_template_entry *entry)
  * ima_alloc_init_template - create and initialize a new template entry
  */
 int ima_alloc_init_template(struct ima_event_data *event_data,
-			    struct ima_template_entry **entry)
+			    struct ima_template_entry **entry,
+			    struct ima_template_desc *desc)
 {
-	struct ima_template_desc *template_desc = ima_template_desc_current();
+	struct ima_template_desc *template_desc;
 	int i, result = 0;
 
+	if (desc)
+		template_desc = desc;
+	else
+		template_desc = ima_template_desc_current();
+
 	*entry = kzalloc(sizeof(**entry) + template_desc->num_fields *
 			 sizeof(struct ima_field_data), GFP_NOFS);
 	if (!*entry)
@@ -143,7 +149,7 @@ void ima_add_violation(struct file *file, const unsigned char *filename,
 	/* can overflow, only indicator */
 	atomic_long_inc(&ima_htable.violations);
 
-	result = ima_alloc_init_template(&event_data, &entry);
+	result = ima_alloc_init_template(&event_data, &entry, NULL);
 	if (result < 0) {
 		result = -ENOMEM;
 		goto err_out;
@@ -166,6 +172,7 @@ err_out:
  *        MAY_APPEND)
  * @func: caller identifier
  * @pcr: pointer filled in if matched measure policy sets pcr=
+ * @template_desc: pointer filled in if matched measure policy sets template=
  *
  * The policy is defined in terms of keypairs:
  *		subj=, obj=, type=, func=, mask=, fsmagic=
@@ -178,13 +185,15 @@ err_out:
  *
  */
 int ima_get_action(struct inode *inode, const struct cred *cred, u32 secid,
-		   int mask, enum ima_hooks func, int *pcr)
+		   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, secid, func, mask, flags, pcr,
+				template_desc);
 }
 
 /*
@@ -279,7 +288,8 @@ out:
 void ima_store_measurement(struct integrity_iint_cache *iint,
 			   struct file *file, const unsigned char *filename,
 			   struct evm_ima_xattr_data *xattr_value,
-			   int xattr_len, int pcr)
+			   int xattr_len, int pcr,
+			   struct ima_template_desc *template_desc)
 {
 	static const char op[] = "add_template_measure";
 	static const char audit_cause[] = "ENOMEM";
@@ -296,7 +306,7 @@ void ima_store_measurement(struct integrity_iint_cache *iint,
 	if (iint->measured_pcrs & (0x1 << pcr))
 		return;
 
-	result = ima_alloc_init_template(&event_data, &entry);
+	result = ima_alloc_init_template(&event_data, &entry, template_desc);
 	if (result < 0) {
 		integrity_audit_msg(AUDIT_INTEGRITY_PCR, inode, filename,
 				    op, audit_cause, result, 0);