From: Changli Gao <xiaosuo@gmail.com>
Date: Thu, 29 Jul 2010 13:41:46 +0000 (+0000)
Subject: act_nat: fix wild pointer
X-Git-Tag: v2.6.35.4~42
X-Git-Url: http://git.ipfire.org/cgi-bin/gitweb.cgi?a=commitdiff_plain;h=1cd65f87cbf31684d778155b31ea32384f8df5d1;p=thirdparty%2Fkernel%2Fstable.git

act_nat: fix wild pointer

[ Upstream commit 072d79a31a3b870b49886f4347e23f81b7eca3ac ]

pskb_may_pull() may change skb pointers, so adjust icmph after pskb_may_pull().

Signed-off-by: Changli Gao <xiaosuo@gmail.com>
Acked-by: Herbert Xu <herbert@gondor.apana.org.au>
Signed-off-by: David S. Miller <davem@davemloft.net>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
---

diff --git a/net/sched/act_nat.c b/net/sched/act_nat.c
index 4e7c24ae2ac55..abbf4fa66a0b9 100644
--- a/net/sched/act_nat.c
+++ b/net/sched/act_nat.c
@@ -218,6 +218,7 @@ static int tcf_nat(struct sk_buff *skb, struct tc_action *a,
 		if (!pskb_may_pull(skb, ihl + sizeof(*icmph) + sizeof(*iph)))
 			goto drop;
 
+		icmph = (void *)(skb_network_header(skb) + ihl);
 		iph = (void *)(icmph + 1);
 		if (egress)
 			addr = iph->daddr;