From patchwork Fri Jul 1 09:48:33 2016 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Christophe Leroy X-Patchwork-Id: 642980 X-Patchwork-Delegate: davem@davemloft.net Return-Path: X-Original-To: patchwork-incoming@ozlabs.org Delivered-To: patchwork-incoming@ozlabs.org Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by ozlabs.org (Postfix) with ESMTP id 3rgxr604xsz9s9W for ; Fri, 1 Jul 2016 23:21:10 +1000 (AEST) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1752675AbcGANVG (ORCPT ); Fri, 1 Jul 2016 09:21:06 -0400 Received: from pegase1.c-s.fr ([93.17.236.30]:5819 "EHLO pegase1.c-s.fr" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1752445AbcGANVE (ORCPT ); Fri, 1 Jul 2016 09:21:04 -0400 Received: from localhost (unknown [192.168.12.234]) by localhost (Postfix) with ESMTP id 3rgs6n5LdQz9ttRY; Fri, 1 Jul 2016 11:48:33 +0200 (CEST) X-Virus-Scanned: Debian amavisd-new at c-s.fr Received: from pegase1.c-s.fr ([192.168.12.234]) by localhost (pegase1.c-s.fr [192.168.12.234]) (amavisd-new, port 10024) with ESMTP id CmNXUkd0rdpF; Fri, 1 Jul 2016 11:48:33 +0200 (CEST) Received: from messagerie.si.c-s.fr (messagerie.si.c-s.fr [192.168.25.192]) by pegase1.c-s.fr (Postfix) with ESMTP id 3rgs6n480jz9ttRV; Fri, 1 Jul 2016 11:48:33 +0200 (CEST) Received: from localhost (localhost [127.0.0.1]) by messagerie.si.c-s.fr (Postfix) with ESMTP id 041AE8B898; Fri, 1 Jul 2016 11:48:34 +0200 (CEST) X-Virus-Scanned: amavisd-new at c-s.fr Received: from messagerie.si.c-s.fr ([127.0.0.1]) by localhost (messagerie.si.c-s.fr [127.0.0.1]) (amavisd-new, port 10023) with ESMTP id RMsNl5koh9xp; Fri, 1 Jul 2016 11:48:33 +0200 (CEST) Received: from PO10863.localdomain (po10863.idsi0.si.c-s.fr [172.25.231.6]) by messagerie.si.c-s.fr (Postfix) with ESMTP id D5B198B892; Fri, 1 Jul 2016 11:48:33 +0200 (CEST) Received: by localhost.localdomain (Postfix, from userid 0) id B281E1A23A2; Fri, 1 Jul 2016 11:48:33 +0200 (CEST) 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: netdev-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: netdev@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; }