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authorEric Dumazet <edumazet@google.com>2019-04-23 09:43:26 -0700
committerGreg Kroah-Hartman <gregkh@linuxfoundation.org>2019-05-05 14:42:37 +0200
commit485f382f2c6da326e5ceea085f45257c71f6f907 (patch)
treea38ba17b27eca3195e0b853929b9f67259a1357e
parente571a33963f4d58f2780253635b1361ab7692d7b (diff)
l2tp: use rcu_dereference_sk_user_data() in l2tp_udp_encap_recv()
[ Upstream commit c1c477217882c610a2ba0268f5faf36c9c092528 ] 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: d00fa9adc528 ("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> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
-rw-r--r--net/l2tp/l2tp_core.c2
1 files changed, 1 insertions, 1 deletions
diff --git a/net/l2tp/l2tp_core.c b/net/l2tp/l2tp_core.c
index fa789c082c3e..52b5a2797c0c 100644
--- a/net/l2tp/l2tp_core.c
+++ b/net/l2tp/l2tp_core.c
@@ -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;