From bc73e38cee0626945a70cb0c2d873aaae3795130 Mon Sep 17 00:00:00 2001
From: Patrick McHardy <kaber@trash.net>
Date: Fri, 5 Apr 2013 08:13:30 +0000
Subject: netfilter: nf_ct_sip: don't drop packets with offsets pointing
 outside the packet

commit 3a7b21eaf4fb3c971bdb47a98f570550ddfe4471 upstream.

Some Cisco phones create huge messages that are spread over multiple packets.
After calculating the offset of the SIP body, it is validated to be within
the packet and the packet is dropped otherwise. This breaks operation of
these phones. Since connection tracking is supposed to be passive, just let
those packets pass unmodified and untracked.

Signed-off-by: Patrick McHardy <kaber@trash.net>
Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

diff --git a/net/netfilter/nf_conntrack_sip.c b/net/netfilter/nf_conntrack_sip.c
index df8f4f2..b4e0d1c 100644
--- a/net/netfilter/nf_conntrack_sip.c
+++ b/net/netfilter/nf_conntrack_sip.c
@@ -1547,7 +1547,7 @@ static int sip_help_tcp(struct sk_buff *skb, unsigned int protoff,
 
 		msglen = origlen = end - dptr;
 		if (msglen > datalen)
-			return NF_DROP;
+			return NF_ACCEPT;
 
 		ret = process_sip_msg(skb, ct, protoff, dataoff,
 				      &dptr, &msglen);
-- 
cgit v0.10.2