[PATCH net-next v3 2/8] gtp: switch from struct socket to struct sock for the GTP sockets

[David Miller]

From: Andreas Schultz <aschultz at tpip.net>
Date: Mon, 13 Feb 2017 16:36:18 +0100

> +	if (gtp->sk0) {
> +		udp_sk(gtp->sk0)->encap_type = 0;
> +		rcu_assign_sk_user_data(gtp->sk0, NULL);
> +		sock_put(gtp->sk0);
>  	}

This does "sock_put(NULL);" because you are assigning gtp->sk0 to
NULL before the sock_put() call.  So you are leaking the socket,
at best.

You need to load the socket pointer into a local variable in order
to do this correctly.