From 2a5b82751f73a0bf6f604ce56d34adba6da1b246 Mon Sep 17 00:00:00 2001 From: "Denis V. Lunev" 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 for initial problem finding in IPv4 code. Signed-off-by: Denis V. Lunev Signed-off-by: David S. Miller --- 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 b585c850a89a..10e22fd48222 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; -- 2.20.1