Commit c1c47721 authored Apr 23, 2019 by Eric Dumazet Committed by David S. Miller Apr 26, 2019

l2tp: use rcu_dereference_sk_user_data() in l2tp_udp_encap_recv()



Canonical way to fetch sk_user_data from an encap_rcv() handler called
from UDP stack in rcu protected section is to use rcu_dereference_sk_user_data(),
otherwise compiler might read it multiple times.

Fixes: d00fa9ad ("il2tp: fix races with tunnel socket close")
Signed-off-by: Eric Dumazet <edumazet@google.com>
Cc: James Chapman <jchapman@katalix.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

parent ad759c90

net/l2tp/l2tp_core.c

+1 −1

Original line number	Diff line number	Diff line
		@@ -909,7 +909,7 @@ int l2tp_udp_encap_recv(struct sock sk, struct sk_buff skb)
		{
		struct l2tp_tunnel *tunnel;

		tunnel = l2tp_tunnel(sk);
		tunnel = rcu_dereference_sk_user_data(sk);
		if (tunnel == NULL)
		goto pass_up;