From 2a5b82751f73a0bf6f604ce56d34adba6da1b246 Mon Sep 17 00:00:00 2001
From: "Denis V. Lunev" <den@openvz.org>
Date: Wed, 1 Oct 2008 02:13:16 -0700
Subject: [PATCH] ipv6: NULL pointer dereferrence in tcp_v6_send_ack
The following actions are possible:
tcp_v6_rcv
skb->dev = NULL;
tcp_v6_do_rcv
tcp_v6_hnd_req
tcp_check_req
req->rsk_ops->send_ack == tcp_v6_send_ack
So, skb->dev can be NULL in tcp_v6_send_ack. We must obtain namespace
from dst entry.
Thanks to Vitaliy Gusev <vgusev@openvz.org> for initial problem finding
in IPv4 code.
Signed-off-by: Denis V. Lunev <den@openvz.org>
Signed-off-by: David S. Miller <davem@davemloft.net>
---
net/ipv6/tcp_ipv6.c | 2 +-
1 file changed, 1 insertion(+), 1 deletion(-)
diff --git a/net/ipv6/tcp_ipv6.c b/net/ipv6/tcp_ipv6.c
index b585c850a89..10e22fd4822 100644
--- a/net/ipv6/tcp_ipv6.c
+++ b/net/ipv6/tcp_ipv6.c
@@ -1050,7 +1050,7 @@ static void tcp_v6_send_ack(struct sk_buff *skb, u32 seq, u32 ack, u32 win, u32
struct tcphdr *th = tcp_hdr(skb), *t1;
struct sk_buff *buff;
struct flowi fl;
- struct net *net = dev_net(skb->dev);
+ struct net *net = dev_net(skb->dst->dev);
struct sock *ctl_sk = net->ipv6.tcp_sk;
unsigned int tot_len = sizeof(struct tcphdr);
__be32 *topt;
--
2.41.3