From 880e4c22700dc2e3ee0f3764b4dafae49579a7b7 Mon Sep 17 00:00:00 2001 From: =?UTF-8?q?Sebastian=20P=C3=B6hn?= Date: Mon, 20 Apr 2015 09:19:20 +0200 Subject: [PATCH] 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 Signed-off-by: David S. Miller Signed-off-by: Greg Kroah-Hartman --- net/ipv4/ip_forward.c | 3 +++ 1 file changed, 3 insertions(+) diff --git a/net/ipv4/ip_forward.c b/net/ipv4/ip_forward.c index ecb34b5ea42f..57075c4508f7 100644 --- a/net/ipv4/ip_forward.c +++ b/net/ipv4/ip_forward.c @@ -127,6 +127,9 @@ int ip_forward(struct sk_buff *skb) 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;