net/handshake: restore destructor on submit failure

handshake_req_submit() replaces sk->sk_destruct but never restores it when
submission fails before the request is hashed. handshake_sk_destruct() then
returns early and the original destructor never runs, leaking the socket.
Restore sk_destruct on the error path.

Fixes: 3b3009e ("net/handshake: Create a NETLINK service for handling handshake requests")
Reviewed-by: Chuck Lever <chuck.lever@oracle.com>
Cc: stable@vger.kernel.org
Signed-off-by: caoping <caoping@cmss.chinamobile.com>
Link: https://patch.msgid.link/20251204091058.1545151-1-caoping@cmss.chinamobile.com
Signed-off-by: Jakub Kicinski <kuba@kernel.org>

Author: caoping

net/handshake/request.c

@@ -276,6 +276,8 @@ int handshake_req_submit(struct socket *sock, struct handshake_req *req,
 out_unlock:
 	spin_unlock(&hn->hn_lock);
 out_err:
+	/* Restore original destructor so socket teardown still runs on failure */
+	req->hr_sk->sk_destruct = req->hr_odestruct;
 	trace_handshake_submit_err(net, req, req->hr_sk, ret);
 	handshake_req_destroy(req);
 	return ret;