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=-0.8 required=3.0 tests=HEADER_FROM_DIFFERENT_DOMAINS, MAILING_LIST_MULTI,SPF_HELO_NONE,SPF_PASS 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 AD448C3A5A6 for ; Tue, 27 Aug 2019 21:19:57 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id 82910214DA for ; Tue, 27 Aug 2019 21:19:57 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1730685AbfH0VTx (ORCPT ); Tue, 27 Aug 2019 17:19:53 -0400 Received: from shards.monkeyblade.net ([23.128.96.9]:50866 "EHLO shards.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1726871AbfH0VTx (ORCPT ); Tue, 27 Aug 2019 17:19:53 -0400 Received: from localhost (unknown [IPv6:2601:601:9f80:35cd::d71]) (using TLSv1 with cipher AES256-SHA (256/256 bits)) (Client did not present a certificate) (Authenticated sender: davem-davemloft) by shards.monkeyblade.net (Postfix) with ESMTPSA id A682A1534D21E; Tue, 27 Aug 2019 14:19:52 -0700 (PDT) Date: Tue, 27 Aug 2019 14:19:50 -0700 (PDT) Message-Id: <20190827.141950.540994003351676048.davem@davemloft.net> To: leonardo@linux.ibm.com Cc: pablo@netfilter.org, netfilter-devel@vger.kernel.org, coreteam@netfilter.org, netdev@vger.kernel.org, linux-kernel@vger.kernel.org, kadlec@netfilter.org, fw@strlen.de, kuznet@ms2.inr.ac.ru, yoshfuji@linux-ipv6.org Subject: Re: [PATCH v2 1/1] netfilter: nf_tables: fib: Drop IPV6 packages if IPv6 is disabled on boot From: David Miller In-Reply-To: <77c43754ff72e9a2e8048ccd032351cf0186080a.camel@linux.ibm.com> References: <20190821141505.2394-1-leonardo@linux.ibm.com> <20190827103541.vzwqwg4jlbuzajxu@salvia> <77c43754ff72e9a2e8048ccd032351cf0186080a.camel@linux.ibm.com> X-Mailer: Mew version 6.8 on Emacs 26.1 Mime-Version: 1.0 Content-Type: Text/Plain; charset=us-ascii Content-Transfer-Encoding: 7bit X-Greylist: Sender succeeded SMTP AUTH, not delayed by milter-greylist-4.5.12 (shards.monkeyblade.net [149.20.54.216]); Tue, 27 Aug 2019 14:19:53 -0700 (PDT) Sender: netdev-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: netdev@vger.kernel.org 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. If ipv6 is disabled ipv6 traffic should not pass through the machine by any means whatsoever. Otherwise there is no point to the knob and we will keep having to add hack checks all over the tree instead of fixing the fundamental issue.