From mboxrd@z Thu Jan 1 00:00:00 1970 From: Pablo Neira Ayuso Subject: [PATCH 1/4] netfilter: nf_ct_sip: don't drop packets with offsets pointing outside the packet Date: Fri, 12 Apr 2013 12:13:16 +0200 Message-ID: <1365761599-6990-2-git-send-email-pablo@netfilter.org> References: <1365761599-6990-1-git-send-email-pablo@netfilter.org> Cc: davem@davemloft.net, netdev@vger.kernel.org To: netfilter-devel@vger.kernel.org Return-path: Received: from mail.us.es ([193.147.175.20]:45005 "EHLO mail.us.es" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1752557Ab3DLKN2 (ORCPT ); Fri, 12 Apr 2013 06:13:28 -0400 In-Reply-To: <1365761599-6990-1-git-send-email-pablo@netfilter.org> Sender: netfilter-devel-owner@vger.kernel.org List-ID: From: Patrick McHardy 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 Signed-off-by: Pablo Neira Ayuso --- net/netfilter/nf_conntrack_sip.c | 6 ++---- 1 file changed, 2 insertions(+), 4 deletions(-) diff --git a/net/netfilter/nf_conntrack_sip.c b/net/netfilter/nf_conntrack_sip.c index 0e7d423..e0c4373 100644 --- a/net/netfilter/nf_conntrack_sip.c +++ b/net/netfilter/nf_conntrack_sip.c @@ -1593,10 +1593,8 @@ static int sip_help_tcp(struct sk_buff *skb, unsigned int protoff, end += strlen("\r\n\r\n") + clen; msglen = origlen = end - dptr; - if (msglen > datalen) { - nf_ct_helper_log(skb, ct, "incomplete/bad SIP message"); - return NF_DROP; - } + if (msglen > datalen) + return NF_ACCEPT; ret = process_sip_msg(skb, ct, protoff, dataoff, &dptr, &msglen); -- 1.7.10.4