Phonet: listening socket lock protects the connected socket list

The accept()'d socket need to be unhashed while the (listen()'ing)
socket lock is held. This fixes a race condition that could lead to an
OOPS.
Signed-off-by: NRémi Denis-Courmont <remi.denis-courmont@nokia.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

net/phonet/pep.c

@@ -1045,12 +1045,12 @@ static void pep_sock_unhash(struct sock *sk)
 	lock_sock(sk);
 	if ((1 << sk->sk_state) & ~(TCPF_CLOSE|TCPF_LISTEN)) {
 		skparent = pn->listener;
-		sk_del_node_init(sk);
 		release_sock(sk);
 
-		sk = skparent;
 		pn = pep_sk(skparent);
-		lock_sock(sk);
+		lock_sock(skparent);
+		sk_del_node_init(sk);
+		sk = skparent;
 	}
 	/* Unhash a listening sock only when it is closed
 	 * and all of its active connected pipes are closed. */