From patchwork Thu Sep 8 09:57:54 2022 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Florian Westphal X-Patchwork-Id: 12969879 X-Patchwork-Delegate: kuba@kernel.org Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by smtp.lore.kernel.org (Postfix) with ESMTP id B9C5EC6FA82 for ; Thu, 8 Sep 2022 09:58:36 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S229656AbiIHJ6e (ORCPT ); Thu, 8 Sep 2022 05:58:34 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:60894 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S229517AbiIHJ6d (ORCPT ); Thu, 8 Sep 2022 05:58:33 -0400 Received: from Chamillionaire.breakpoint.cc (Chamillionaire.breakpoint.cc [IPv6:2a0a:51c0:0:12e:520::1]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 2C72DAA4EB; Thu, 8 Sep 2022 02:58:32 -0700 (PDT) Received: from fw by Chamillionaire.breakpoint.cc with local (Exim 4.92) (envelope-from ) id 1oWEIl-0002vq-18; Thu, 08 Sep 2022 11:58:27 +0200 From: Florian Westphal To: Cc: Jakub Kicinski , "David S. Miller" , Eric Dumazet , Paolo Abeni , , Igor Ryzhov , Florian Westphal Subject: [PATCH net 1/4] netfilter: nf_conntrack_sip: fix ct_sip_walk_headers Date: Thu, 8 Sep 2022 11:57:54 +0200 Message-Id: <20220908095757.1755-2-fw@strlen.de> X-Mailer: git-send-email 2.35.1 In-Reply-To: <20220908095757.1755-1-fw@strlen.de> References: <20220908095757.1755-1-fw@strlen.de> MIME-Version: 1.0 Precedence: bulk List-ID: X-Mailing-List: netdev@vger.kernel.org X-Patchwork-Delegate: kuba@kernel.org From: Igor Ryzhov ct_sip_next_header and ct_sip_get_header return an absolute value of matchoff, not a shift from current dataoff. So dataoff should be assigned matchoff, not incremented by it. This issue can be seen in the scenario when there are multiple Contact headers and the first one is using a hostname and other headers use IP addresses. In this case, ct_sip_walk_headers will work as follows: The first ct_sip_get_header call to will find the first Contact header but will return -1 as the header uses a hostname. But matchoff will be changed to the offset of this header. After that, dataoff should be set to matchoff, so that the next ct_sip_get_header call find the next Contact header. But instead of assigning dataoff to matchoff, it is incremented by it, which is not correct, as matchoff is an absolute value of the offset. So on the next call to the ct_sip_get_header, dataoff will be incorrect, and the next Contact header may not be found at all. Fixes: 05e3ced297fe ("[NETFILTER]: nf_conntrack_sip: introduce SIP-URI parsing helper") Signed-off-by: Igor Ryzhov Signed-off-by: Florian Westphal --- net/netfilter/nf_conntrack_sip.c | 4 ++-- 1 file changed, 2 insertions(+), 2 deletions(-) diff --git a/net/netfilter/nf_conntrack_sip.c b/net/netfilter/nf_conntrack_sip.c index daf06f71d31c..77f5e82d8e3f 100644 --- a/net/netfilter/nf_conntrack_sip.c +++ b/net/netfilter/nf_conntrack_sip.c @@ -477,7 +477,7 @@ static int ct_sip_walk_headers(const struct nf_conn *ct, const char *dptr, return ret; if (ret == 0) break; - dataoff += *matchoff; + dataoff = *matchoff; } *in_header = 0; } @@ -489,7 +489,7 @@ static int ct_sip_walk_headers(const struct nf_conn *ct, const char *dptr, break; if (ret == 0) return ret; - dataoff += *matchoff; + dataoff = *matchoff; } if (in_header)