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| author | Eric Dumazet <edumazet@google.com> | 2019-04-23 09:43:26 -0700 |
|---|---|---|
| committer | Greg Kroah-Hartman <gregkh@linuxfoundation.org> | 2019-05-05 14:42:37 +0200 |
| commit | 485f382f2c6da326e5ceea085f45257c71f6f907 (patch) | |
| tree | a38ba17b27eca3195e0b853929b9f67259a1357e | |
| parent | e571a33963f4d58f2780253635b1361ab7692d7b (diff) | |
| download | linux-stable-485f382f2c6da326e5ceea085f45257c71f6f907.tar.gz linux-stable-485f382f2c6da326e5ceea085f45257c71f6f907.tar.bz2 linux-stable-485f382f2c6da326e5ceea085f45257c71f6f907.zip | |
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.c | 2 |
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; |