ip_forward: Drop frames with attached skb->sk
[ Upstream commit 2ab957492d13bb819400ac29ae55911d50a82a13 ]
Initial discussion was:
[FYI] xfrm: Don't lookup sk_policy for timewait sockets
Forwarded frames should not have a socket attached. Especially
tw sockets will lead to panics later-on in the stack.
This was observed with TPROXY assigning a tw socket and broken
policy routing (misconfigured). As a result frame enters
forwarding path instead of input. We cannot solve this in
TPROXY as it cannot know that policy routing is broken.
v2:
Remove useless comment
Signed-off-by: Sebastian Poehn <sebastian.poehn@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Signed-off-by: Ben Hutchings <ben@decadent.org.uk>
(cherry picked from commit fccb908d23fbae3e941e9294590dd94de6b1d822)
Signed-off-by: Willy Tarreau <w@1wt.eu>
Signed-off-by: Stefan Bader <stefan.bader@canonical.com>
diff --git a/net/ipv4/ip_forward.c b/net/ipv4/ip_forward.c
index a2991bc..6be4340 100644
--- a/net/ipv4/ip_forward.c
+++ b/net/ipv4/ip_forward.c
@@ -56,6 +56,9 @@
struct rtable *rt; /* Route we use */
struct ip_options * opt = &(IPCB(skb)->opt);
+ if (unlikely(skb->sk))
+ goto drop;
+
if (skb_warn_if_lro(skb))
goto drop;
