From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S932094AbcGAJte (ORCPT ); Fri, 1 Jul 2016 05:49:34 -0400 Received: from pegase1.c-s.fr ([93.17.236.30]:64076 "EHLO pegase1.c-s.fr" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1752252AbcGAJtI (ORCPT ); Fri, 1 Jul 2016 05:49:08 -0400 From: Christophe Leroy Subject: [PATCH] netfilter: nf_conntrack_sip: CSeq 0 is a valid CSeq To: Pablo Neira Ayuso , Patrick McHardy , Jozsef Kadlecsik , "David S. Miller" Cc: netfilter-devel@vger.kernel.org, coreteam@netfilter.org, netdev@vger.kernel.org, linux-kernel@vger.kernel.org Message-Id: <20160701094833.B281E1A23A2@localhost.localdomain> Date: Fri, 1 Jul 2016 11:48:33 +0200 (CEST) Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Do not drop packet when CSeq is 0 as 0 is also a valid value for CSeq. In order to do so, we replace obsolete simple_strtoul() which returns 0 on error by kstrtouint(). As kstrtouint() requires a NULL terminated string, we need to use a temporary buffer Signed-off-by: Christophe Leroy --- net/netfilter/nf_conntrack_sip.c | 20 ++++++++++++++++---- 1 file changed, 16 insertions(+), 4 deletions(-) diff --git a/net/netfilter/nf_conntrack_sip.c b/net/netfilter/nf_conntrack_sip.c index f72ba55..e770477 100644 --- a/net/netfilter/nf_conntrack_sip.c +++ b/net/netfilter/nf_conntrack_sip.c @@ -1368,6 +1368,7 @@ static int process_sip_response(struct sk_buff *skb, unsigned int protoff, struct nf_conn *ct = nf_ct_get(skb, &ctinfo); unsigned int matchoff, matchlen, matchend; unsigned int code, cseq, i; + char buf[21]; if (*datalen < strlen("SIP/2.0 200")) return NF_ACCEPT; @@ -1382,8 +1383,13 @@ static int process_sip_response(struct sk_buff *skb, unsigned int protoff, nf_ct_helper_log(skb, ct, "cannot parse cseq"); return NF_DROP; } - cseq = simple_strtoul(*dptr + matchoff, NULL, 10); - if (!cseq) { + if (matchlen > sizeof(buf) - 1) { + nf_ct_helper_log(skb, ct, "cannot parse cseq (too big)"); + return NF_DROP; + } + memcpy(buf, *dptr + matchoff, matchlen); + buf[matchlen] = 0; + if (kstrtouint(buf, 10, &cseq)) { nf_ct_helper_log(skb, ct, "cannot get cseq"); return NF_DROP; } @@ -1432,6 +1438,7 @@ static int process_sip_request(struct sk_buff *skb, unsigned int protoff, for (i = 0; i < ARRAY_SIZE(sip_handlers); i++) { const struct sip_handler *handler; + char buf[21]; handler = &sip_handlers[i]; if (handler->request == NULL) @@ -1445,8 +1452,13 @@ static int process_sip_request(struct sk_buff *skb, unsigned int protoff, nf_ct_helper_log(skb, ct, "cannot parse cseq"); return NF_DROP; } - cseq = simple_strtoul(*dptr + matchoff, NULL, 10); - if (!cseq) { + if (matchlen > sizeof(buf) - 1) { + nf_ct_helper_log(skb, ct, "cannot parse cseq(too big)"); + return NF_DROP; + } + memcpy(buf, *dptr + matchoff, matchlen); + buf[matchlen] = 0; + if (kstrtouint(buf, 10, &cseq)) { nf_ct_helper_log(skb, ct, "cannot get cseq"); return NF_DROP; } -- 2.1.0