[3.8.y.z,extended,stable] Patch "netfilter: xt_TCPOPTSTRIP: don't use tcp_hdr()" has been added to staging queue

Message ID 1373387378-23448-1-git-send-email-luis.henriques@canonical.com
State New
Headers show

Commit Message

Luis Henriques July 9, 2013, 4:29 p.m.
This is a note to let you know that I have just added a patch titled

    netfilter: xt_TCPOPTSTRIP: don't use tcp_hdr()

to the linux-3.8.y-queue branch of the 3.8.y.z extended stable tree 
which can be found at:


If you, or anyone else, feels it should not be added to this tree, please 
reply to this email.

For more information about the 3.8.y.z tree, see



From 3dfb1854014f332f9043c8b0c7d8e1dc4cf84d74 Mon Sep 17 00:00:00 2001
From: Pablo Neira Ayuso <pablo@netfilter.org>
Date: Tue, 11 Jun 2013 01:51:31 +0200
Subject: [PATCH] netfilter: xt_TCPOPTSTRIP: don't use tcp_hdr()

commit ed82c437320c48a4032492f4a55a7e2c934158b6 upstream.

In (bc6bcb5 netfilter: xt_TCPOPTSTRIP: fix possible mangling beyond
packet boundary), the use of tcp_hdr was introduced. However, we
cannot assume that skb->transport_header is set for non-local packets.

Cc: Florian Westphal <fw@strlen.de>
Reported-by: Phil Oester <kernel@linuxace.com>
Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
Signed-off-by: Luis Henriques <luis.henriques@canonical.com>
 net/netfilter/xt_TCPOPTSTRIP.c | 6 ++++--
 1 file changed, 4 insertions(+), 2 deletions(-)



diff --git a/net/netfilter/xt_TCPOPTSTRIP.c b/net/netfilter/xt_TCPOPTSTRIP.c
index 1eb1a44..b68fa19 100644
--- a/net/netfilter/xt_TCPOPTSTRIP.c
+++ b/net/netfilter/xt_TCPOPTSTRIP.c
@@ -48,11 +48,13 @@  tcpoptstrip_mangle_packet(struct sk_buff *skb,
 		return NF_DROP;

 	len = skb->len - tcphoff;
-	if (len < (int)sizeof(struct tcphdr) ||
-	    tcp_hdr(skb)->doff * 4 > len)
+	if (len < (int)sizeof(struct tcphdr))
 		return NF_DROP;

 	tcph = (struct tcphdr *)(skb_network_header(skb) + tcphoff);
+	if (tcph->doff * 4 > len)
+		return NF_DROP;
 	opt  = (u_int8_t *)tcph;