ecryptfs: Fix memory leakage in keystore.c

In 'decrypt_pki_encrypted_session_key' function:

Initializes 'payload' pointer and releases it on exit.
Signed-off-by: Geyslan G. Bem <geyslan@gmail.com>
Signed-off-by: Tyler Hicks <tyhicks@canonical.com>
Cc: stable@vger.kernel.org # v2.6.28+

fs/ecryptfs/keystore.c

@@ -1149,7 +1149,7 @@ decrypt_pki_encrypted_session_key(struct ecryptfs_auth_tok *auth_tok,
 	struct ecryptfs_msg_ctx *msg_ctx;
 	struct ecryptfs_message *msg = NULL;
 	char *auth_tok_sig;
-	char *payload;
+	char *payload = NULL;
 	size_t payload_len = 0;
 	int rc;
 
@@ -1203,6 +1203,7 @@ decrypt_pki_encrypted_session_key(struct ecryptfs_auth_tok *auth_tok,
 	}
 out:
 	kfree(msg);
+	kfree(payload);
 	return rc;
 }