ecryptfs: fix a memory leak bug in parse_tag_1_packet()

BugLink: https://bugs.launchpad.net/bugs/1868627

commit fe2e082f upstream.

In parse_tag_1_packet(), if tag 1 packet contains a key larger than
ECRYPTFS_MAX_ENCRYPTED_KEY_BYTES, no cleanup is executed, leading to a
memory leak on the allocated 'auth_tok_list_item'. To fix this issue, go to
the label 'out_free' to perform the cleanup work.

Cc: stable@vger.kernel.org
Fixes: dddfa461 ("[PATCH] eCryptfs: Public key; packet management")
Signed-off-by: Wenwen Wang <wenwen@cs.uga.edu>
Signed-off-by: Tyler Hicks <tyhicks@canonical.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Signed-off-by: Khalid Elmously <khalid.elmously@canonical.com>
Signed-off-by: Kelsey Skunberg <kelsey.skunberg@canonical.com>

fs/ecryptfs/keystore.c

@@ -1280,7 +1280,7 @@ parse_tag_1_packet(struct ecryptfs_crypt_stat *crypt_stat,
 		printk(KERN_ERR "Enter w/ first byte != 0x%.2x\n",
 		       ECRYPTFS_TAG_1_PACKET_TYPE);
 		rc = -EINVAL;
-		goto out;
+		goto out_free;
 	}
 	/* Released: wipe_auth_tok_list called in ecryptfs_parse_packet_set or
 	 * at end of function upon failure */