From mboxrd@z Thu Jan 1 00:00:00 1970 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 05507ECAAA1 for ; Fri, 2 Sep 2022 05:39:57 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S231732AbiIBFjy (ORCPT ); Fri, 2 Sep 2022 01:39:54 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:53886 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S229482AbiIBFjx (ORCPT ); Fri, 2 Sep 2022 01:39:53 -0400 Received: from Chamillionaire.breakpoint.cc (Chamillionaire.breakpoint.cc [IPv6:2a0a:51c0:0:12e:520::1]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id D5C09D6B; Thu, 1 Sep 2022 22:39:51 -0700 (PDT) Received: from fw by Chamillionaire.breakpoint.cc with local (Exim 4.92) (envelope-from ) id 1oTzOq-0007c5-Vx; Fri, 02 Sep 2022 07:39:29 +0200 Date: Fri, 2 Sep 2022 07:39:28 +0200 From: Florian Westphal To: Jakub Kicinski Cc: Florian Westphal , netdev@vger.kernel.org, davem@davemloft.net, netfilter-devel@vger.kernel.org, pabeni@redhat.com, edumazet@google.com, Pablo Neira Ayuso , Aaron Conole Subject: Re: [PATCH net 1/4] netfilter: remove nf_conntrack_helper sysctl and modparam toggles Message-ID: <20220902053928.GA5881@breakpoint.cc> References: <20220901071238.3044-1-fw@strlen.de> <20220901071238.3044-2-fw@strlen.de> <20220901210715.00c7b4e1@kernel.org> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20220901210715.00c7b4e1@kernel.org> User-Agent: Mutt/1.10.1 (2018-07-13) Precedence: bulk List-ID: X-Mailing-List: netfilter-devel@vger.kernel.org Jakub Kicinski wrote: > On Thu, 1 Sep 2022 09:12:35 +0200 Florian Westphal wrote: > > From: Pablo Neira Ayuso > > > > __nf_ct_try_assign_helper() remains in place but it now requires a > > template to configure the helper. > > > > A toggle to disable automatic helper assignment was added by: > > > > a9006892643a ("netfilter: nf_ct_helper: allow to disable automatic helper assignment") > > > > in 2012 to address the issues described in "Secure use of iptables and > > connection tracking helpers". Automatic conntrack helper assignment was > > disabled by: > > > > 3bb398d925ec ("netfilter: nf_ct_helper: disable automatic helper assignment") > > > > back in 2016. > > > > This patch removes the sysctl and modparam toggles, users now have to > > rely on explicit conntrack helper configuration via ruleset. > > > > Update tools/testing/selftests/netfilter/nft_conntrack_helper.sh to > > check that auto-assignment does not happen anymore. > > From the description itself it's unclear why this is a part of a net PR. > Could you elucidate? Yes, there is improper checking in the irc dcc helper, its possible to trigger the 'please do dynamic port forward' from outside by embedding a 'DCC' in a PING request; if the client echos that back a expectation/ port forward gets added. A fix for this will come in the next net PR, however, one part of the issue is that point-blank-autassign is problematic and that helpers should only be enabled for addresses that need it. If you like I can resend the PR with an updated cover letter, or resend with the dcc helper fix included as well.