lkml.org 
[lkml]   [2019]   [Aug]   [10]   [last100]   RSS Feed
Views: [wrap][no wrap]   [headers]  [forward] 
 
Messages in this thread
Patch in this message
/
From
Date
Subject[PATCH 3.16 111/157] l2tp: use rcu_dereference_sk_user_data() in l2tp_udp_encap_recv()
3.16.72-rc1 review patch.  If anyone has any objections, please let me know.

------------------

From: Eric Dumazet <edumazet@google.com>

commit c1c477217882c610a2ba0268f5faf36c9c092528 upstream.

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: Ben Hutchings <ben@decadent.org.uk>
---
net/l2tp/l2tp_core.c | 2 +-
1 file changed, 1 insertion(+), 1 deletion(-)

--- a/net/l2tp/l2tp_core.c
+++ b/net/l2tp/l2tp_core.c
@@ -997,7 +997,7 @@ int l2tp_udp_encap_recv(struct sock *sk,
{
struct l2tp_tunnel *tunnel;

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

\
 
 \ /
  Last update: 2019-08-10 22:51    [W:0.281 / U:1.972 seconds]
©2003-2018 Jasper Spaans|hosted at Digital Ocean and TransIP|Read the blog|Advertise on this site