Re: [PATCH net] l2tp: only return sessions of the given tunnel in l2tp_session_get()

[Guillaume Nault <gnault@redhat.com>]

On Sun, Oct 25, 2026 at 10:58:31AM -0400, Hengyu Liang wrote:
> @@ -315,10 +315,19 @@ EXPORT_SYMBOL_GPL(l2tp_v2_session_get);
>  struct l2tp_session *l2tp_session_get(const struct net *net, struct sock *sk, int pver,
>  				      u32 tunnel_id, u32 session_id)
>  {
> +	struct l2tp_session *session;
> +
>  	if (pver == L2TP_HDR_VER_2)
>  		return l2tp_v2_session_get(net, tunnel_id, session_id);
> -	else
> -		return l2tp_v3_session_get(net, sk, session_id);
> +
> +	/* An L2TPv3 session ID that has not collided may be in any tunnel */
> +	session = l2tp_v3_session_get(net, sk, session_id);
> +	if (session && session->tunnel->tunnel_id != tunnel_id) {
> +		l2tp_session_put(session);
> +		return NULL;
> +	}
> +
> +	return session;
>  }

The original code looks correct to me. L2TPv3 sessions, unlike L2TPv2
ones, are global to all tunnels sharing the same socket.