diff mbox

[3.16.y-ckt,034/180] ip_forward: Drop frames with attached skb->sk

Message ID 1430991989-23170-35-git-send-email-luis.henriques@canonical.com
State New
Headers show

Commit Message

Luis Henriques May 7, 2015, 9:44 a.m. UTC 
3.16.7-ckt11 -stable review patch.  If anyone has any objections, please let me know.

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

From: =?UTF-8?q?Sebastian=20P=C3=B6hn?= <sebastian.poehn@gmail.com>

commit 2ab957492d13bb819400ac29ae55911d50a82a13 upstream.

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: Luis Henriques <luis.henriques@canonical.com>
---
 net/ipv4/ip_forward.c | 3 +++
 1 file changed, 3 insertions(+)
diff mbox

Patch

diff --git a/net/ipv4/ip_forward.c b/net/ipv4/ip_forward.c
index 787b3c294ce6..d5410b57da19 100644
--- a/net/ipv4/ip_forward.c
+++ b/net/ipv4/ip_forward.c
@@ -81,6 +81,9 @@  int ip_forward(struct sk_buff *skb)
 	if (skb->pkt_type != PACKET_HOST)
 		goto drop;
 
+	if (unlikely(skb->sk))
+		goto drop;
+
 	if (skb_warn_if_lro(skb))
 		goto drop;