From d4a71b155c12d0d429c6b69d94076d6d57e2a7a7 Mon Sep 17 00:00:00 2001 From: Pravin B Shelar Date: Wed, 25 Sep 2013 09:57:47 -0700 Subject: [PATCH] ip_tunnel: Do not use stale inner_iph pointer. While sending packet skb_cow_head() can change skb header which invalidates inner_iph pointer to skb header. Following patch avoid using it. Found by code inspection. This bug was introduced by commit 0e6fbc5b6c6218 (ip_tunnels: extend iptunnel_xmit()). Signed-off-by: Pravin B Shelar Acked-by: Eric Dumazet Signed-off-by: David S. Miller --- net/ipv4/ip_tunnel.c | 4 ++-- 1 file changed, 2 insertions(+), 2 deletions(-) diff --git a/net/ipv4/ip_tunnel.c b/net/ipv4/ip_tunnel.c index ac9fabe0300f..d3fbad422e0e 100644 --- a/net/ipv4/ip_tunnel.c +++ b/net/ipv4/ip_tunnel.c @@ -623,6 +623,7 @@ void ip_tunnel_xmit(struct sk_buff *skb, struct net_device *dev, tunnel->err_count = 0; } + tos = ip_tunnel_ecn_encap(tos, inner_iph, skb); ttl = tnl_params->ttl; if (ttl == 0) { if (skb->protocol == htons(ETH_P_IP)) @@ -651,8 +652,7 @@ void ip_tunnel_xmit(struct sk_buff *skb, struct net_device *dev, } err = iptunnel_xmit(rt, skb, fl4.saddr, fl4.daddr, protocol, - ip_tunnel_ecn_encap(tos, inner_iph, skb), ttl, df, - !net_eq(tunnel->net, dev_net(dev))); + tos, ttl, df, !net_eq(tunnel->net, dev_net(dev))); iptunnel_xmit_stats(err, &dev->stats, dev->tstats); return; -- 2.20.1