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 25726C38145 for ; Thu, 8 Sep 2022 21:49:05 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S229585AbiIHVtD (ORCPT ); Thu, 8 Sep 2022 17:49:03 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:59944 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S229476AbiIHVtC (ORCPT ); Thu, 8 Sep 2022 17:49:02 -0400 Received: from Chamillionaire.breakpoint.cc (Chamillionaire.breakpoint.cc [IPv6:2a0a:51c0:0:12e:520::1]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 8C331F3BE2 for ; Thu, 8 Sep 2022 14:49:01 -0700 (PDT) Received: from fw by Chamillionaire.breakpoint.cc with local (Exim 4.92) (envelope-from ) id 1oWPON-0008Oi-BY; Thu, 08 Sep 2022 23:48:59 +0200 Date: Thu, 8 Sep 2022 23:48:59 +0200 From: Florian Westphal To: Chris Clayton Cc: Florian Westphal , "netdev@vger.kernel.org" , Pablo Neira Ayuso Subject: Re: b118509076b3 (probably) breaks my firewall Message-ID: <20220908214859.GD16543@breakpoint.cc> References: <20220908191925.GB16543@breakpoint.cc> <78611fbd-434e-c948-5677-a0bdb66f31a5@googlemail.com> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <78611fbd-434e-c948-5677-a0bdb66f31a5@googlemail.com> User-Agent: Mutt/1.10.1 (2018-07-13) Precedence: bulk List-ID: X-Mailing-List: netdev@vger.kernel.org Chris Clayton wrote: [ CC Pablo ] > On 08/09/2022 20:19, Florian Westphal wrote: > > Chris Clayton wrote: > >> Just a heads up and a question... > >> > >> I've pulled the latest and greatest from Linus' tree and built and installed the kernel. git describe gives > >> v6.0-rc4-126-g26b1224903b3. > >> > >> I find that my firewall is broken because /proc/sys/net/netfilter/nf_conntrack_helper no longer exists. It existed on an > >> -rc4 kernel. Are changes like this supposed to be introduced at this stage of the -rc cycle? > > > > The problem is that the default-autoassign (nf_conntrack_helper=1) has > > side effects that most people are not aware of. > > > > The bug that propmpted this toggle from getting axed was that the irc (dcc) helper allowed > > a remote client to create a port forwarding to the local client. > > > Ok, but I still think it's not the sort of change that should be introduced at this stage of the -rc cycle. > The other problem is that the documentation (Documentation/networking/nf_conntrack-sysctl.rst) hasn't been updated. So I > know my firewall is broken but there's nothing I can find that tells me how to fix it. Pablo, I don't think revert+move the 'next' will avoid this kinds of problems, but at least the nf_conntrack-sysctl.rst should be amended to reflect that this was removed. I'd keep it though because people that see an error wrt. this might be looking at nf_conntrack-sysctl.rst. Maybe just a link to https://home.regit.org/netfilter-en/secure-use-of-helpers/? What do you think?