From mboxrd@z Thu Jan 1 00:00:00 1970 From: Pablo Neira Ayuso Subject: Re: [PATCH v2 nf] netfilter: don't track fragmented packets Date: Wed, 8 Mar 2017 18:30:46 +0100 Message-ID: <20170308173046.GA8605@salvia> References: <20170303204400.21565-1-fw@strlen.de> Mime-Version: 1.0 Content-Type: text/plain; charset=us-ascii Cc: netfilter-devel@vger.kernel.org To: Florian Westphal Return-path: Received: from mail.us.es ([193.147.175.20]:35480 "EHLO mail.us.es" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1753930AbdCHRjn (ORCPT ); Wed, 8 Mar 2017 12:39:43 -0500 Received: from antivirus1-rhel7.int (unknown [192.168.2.11]) by mail.us.es (Postfix) with ESMTP id 73BBB1B2B6E for ; Wed, 8 Mar 2017 18:30:50 +0100 (CET) Received: from antivirus1-rhel7.int (localhost [127.0.0.1]) by antivirus1-rhel7.int (Postfix) with ESMTP id 66BEFDA729 for ; Wed, 8 Mar 2017 18:30:50 +0100 (CET) Received: from antivirus1-rhel7.int (localhost [127.0.0.1]) by antivirus1-rhel7.int (Postfix) with ESMTP id 7689BDA80C for ; Wed, 8 Mar 2017 18:30:47 +0100 (CET) Content-Disposition: inline In-Reply-To: <20170303204400.21565-1-fw@strlen.de> Sender: netfilter-devel-owner@vger.kernel.org List-ID: On Fri, Mar 03, 2017 at 09:44:00PM +0100, Florian Westphal wrote: > Andrey reports syzkaller splat caused by > > NF_CT_ASSERT(!ip_is_fragment(ip_hdr(skb))); > > in ipv4 nat. But this assertion (and the comment) are wrong, this function > does see fragments when IP_NODEFRAG setsockopt is used. > > As conntrack doesn't track packets without complete l4 header, only the > first fragment is tracked. > > Because applying nat to first packet but not the rest makes no sense this > also turns off tracking of all fragments. Applied, thanks Florian.