From: Haishuang Yan <yanhaishuang@cmss.chinamobile.com>
Date: Sun, 4 Jun 2017 06:43:43 +0000 (+0800)
Subject: sit: reload iphdr in ipip6_rcv
X-Git-Url: http://git.cdn.openwrt.org/?a=commitdiff_plain;h=b699d0035836f6712917a41e7ae58d84359b8ff9;p=openwrt%2Fstaging%2Fblogic.git

sit: reload iphdr in ipip6_rcv

Since iptunnel_pull_header() can call pskb_may_pull(),
we must reload any pointer that was related to skb->head.

Fixes: a09a4c8dd1ec ("tunnels: Remove encapsulation offloads on decap")
Signed-off-by: Haishuang Yan <yanhaishuang@cmss.chinamobile.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
---

diff --git a/net/ipv6/sit.c b/net/ipv6/sit.c
index 61e5902f0687..af832e7ce80f 100644
--- a/net/ipv6/sit.c
+++ b/net/ipv6/sit.c
@@ -657,6 +657,7 @@ static int ipip6_rcv(struct sk_buff *skb)
 		if (iptunnel_pull_header(skb, 0, htons(ETH_P_IPV6),
 		    !net_eq(tunnel->net, dev_net(tunnel->dev))))
 			goto out;
+		iph = ip_hdr(skb);
 
 		err = IP_ECN_decapsulate(iph, skb);
 		if (unlikely(err)) {