ksmbd: fix memory leak in smb2_lock()

[ Upstream commit 8f1752723019db900fb60a5b9d0dfd3a2bdea36c ]

In smb2_lock(), if setup_async_work() executes successfully,
work->cancel_argv will bind the argv that generated by kmalloc(). And
release_async_work() is called in ksmbd_conn_try_dequeue_request() or
smb2_lock() to release argv.
However, when setup_async_work function fails, work->cancel_argv has not
been bound to the argv, resulting in the previously allocated argv not
being released. Call kfree() to fix it.

Fixes: e2f34481b2 ("cifsd: add server-side procedures for SMB3")
Signed-off-by: Zizhi Wo <wozizhi@huawei.com>
Acked-by: Namjae Jeon <linkinjeon@kernel.org>
Signed-off-by: Steve French <stfrench@microsoft.com>
Signed-off-by: Sasha Levin <sashal@kernel.org>

fs/smb/server/smb2pdu.c

@@ -7074,6 +7074,7 @@ skip:
 						      smb2_remove_blocked_lock,
 						      argv);
 				if (rc) {
+					kfree(argv);
 					err = -ENOMEM;
 					goto out;
 				}