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 X-Spam-Level: X-Spam-Status: No, score=-2.2 required=3.0 tests=HEADER_FROM_DIFFERENT_DOMAINS, MAILING_LIST_MULTI,SPF_HELO_NONE,SPF_PASS,USER_AGENT_SANE_1 autolearn=no autolearn_force=no version=3.4.0 Received: from mail.kernel.org (mail.kernel.org [198.145.29.99]) by smtp.lore.kernel.org (Postfix) with ESMTP id BEB31C3A5A4 for ; Wed, 28 Aug 2019 10:17:31 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id A0A8C2189D for ; Wed, 28 Aug 2019 10:17:31 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1727233AbfH1KR1 (ORCPT ); Wed, 28 Aug 2019 06:17:27 -0400 Received: from Chamillionaire.breakpoint.cc ([193.142.43.52]:43672 "EHLO Chamillionaire.breakpoint.cc" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1727055AbfH1KRU (ORCPT ); Wed, 28 Aug 2019 06:17:20 -0400 Received: from fw by Chamillionaire.breakpoint.cc with local (Exim 4.92) (envelope-from ) id 1i2v0q-0001sT-6P; Wed, 28 Aug 2019 12:17:12 +0200 Date: Wed, 28 Aug 2019 12:17:12 +0200 From: Florian Westphal To: Pablo Neira Ayuso Cc: Florian Westphal , David Miller , netfilter-devel@vger.kernel.org Subject: Re: [PATCH v2 1/1] netfilter: nf_tables: fib: Drop IPV6 packages if IPv6 is disabled on boot Message-ID: <20190828101712.GF20113@breakpoint.cc> References: <20190827.141950.540994003351676048.davem@davemloft.net> <20190827215836.GA10942@strlen.de> <20190828081942.isdjcdvcqok2a6zz@salvia> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20190828081942.isdjcdvcqok2a6zz@salvia> User-Agent: Mutt/1.10.1 (2018-07-13) Sender: netfilter-devel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: netfilter-devel@vger.kernel.org Pablo Neira Ayuso wrote: > On Tue, Aug 27, 2019 at 11:58:36PM +0200, Florian Westphal wrote: > > David Miller wrote: > > > From: Leonardo Bras > > > Date: Tue, 27 Aug 2019 14:34:14 -0300 > > > > > > > I could reproduce this bug on a host ('ipv6.disable=1') starting a > > > > guest with a virtio-net interface with 'filterref' over a virtual > > > > bridge. It crashes the host during guest boot (just before login). > > > > > > > > By that I could understand that a guest IPv6 network traffic > > > > (viavirtio-net) may cause this kernel panic. > > > > > > Really this is bad and I suspected bridging to be involved somehow. > > > > Thats a good point -- Leonardo, is the > > "net.bridge.bridge-nf-call-ip6tables" sysctl on? > > > > As much as i'd like to send a patch to remove br_netfilter, I fear > > we can't even stop passing ipv6 packets up to netfilter if > > ipv6.disable=1 is set because users might be using ip6tables for > > bridged traffic. > > If the br_netfilter module is in placed, then it's probably better to > perform this check from there. ipt6tables won't work for filtering anymore, so I don't think this is something we can do. Anyway, lets wait for Leonardo to confirm, else this is pointless speculation :-)