ima: free duplicate measurement memory

Info about new measurements are cached in the iint for performance.  When
the inode is flushed from cache, the associated iint is flushed as well.
Subsequent access to the inode will cause the inode to be re-measured and
will attempt to add a duplicate entry to the measurement list.

This patch frees the duplicate measurement memory, fixing a memory leak.

Signed-off-by: Roberto Sassu <roberto.sassu@polito.it>
Signed-off-by: Mimi Zohar <zohar@us.ibm.com>
Cc: stable@vger.kernel.org
diff --git a/security/integrity/ima/ima_api.c b/security/integrity/ima/ima_api.c
index 0d50df0..88a2788 100644
--- a/security/integrity/ima/ima_api.c
+++ b/security/integrity/ima/ima_api.c
@@ -178,8 +178,8 @@
 	strncpy(entry->template.file_name, filename, IMA_EVENT_NAME_LEN_MAX);
 
 	result = ima_store_template(entry, violation, inode);
-	if (!result)
+	if (!result || result == -EEXIST)
 		iint->flags |= IMA_MEASURED;
-	else
+	if (result < 0)
 		kfree(entry);
 }
diff --git a/security/integrity/ima/ima_queue.c b/security/integrity/ima/ima_queue.c
index 8e28f04..e1a5062 100644
--- a/security/integrity/ima/ima_queue.c
+++ b/security/integrity/ima/ima_queue.c
@@ -114,6 +114,7 @@
 		memcpy(digest, entry->digest, sizeof digest);
 		if (ima_lookup_digest_entry(digest)) {
 			audit_cause = "hash_exists";
+			result = -EEXIST;
 			goto out;
 		}
 	}