ecryptfs: fix a memory leak bug in ecryptfs_init_messaging()

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

commit b4a81b87 upstream.

In ecryptfs_init_messaging(), if the allocation for 'ecryptfs_msg_ctx_arr'
fails, the previously allocated 'ecryptfs_daemon_hash' is not deallocated,
leading to a memory leak bug. To fix this issue, free
'ecryptfs_daemon_hash' before returning the error.

Cc: stable@vger.kernel.org
Fixes: 88b4a07e ("[PATCH] eCryptfs: Public key transport mechanism")
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/messaging.c

@@ -397,6 +397,7 @@ int __init ecryptfs_init_messaging(void)
 					* ecryptfs_message_buf_len),
 				       GFP_KERNEL);
 	if (!ecryptfs_msg_ctx_arr) {
+		kfree(ecryptfs_daemon_hash);
 		rc = -ENOMEM;
 		printk(KERN_ERR "%s: Failed to allocate memory\n", __func__);
 		goto out;