From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1755105AbdKKCrX (ORCPT ); Fri, 10 Nov 2017 21:47:23 -0500 Received: from www.llwyncelyn.cymru ([82.70.14.225]:58116 "EHLO fuzix.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1750857AbdKKCrV (ORCPT ); Fri, 10 Nov 2017 21:47:21 -0500 Date: Sat, 11 Nov 2017 02:47:10 +0000 From: Alan Cox To: Patrick McLean Cc: linux-kernel@vger.kernel.org, linux-nfs@vger.kernel.org, stable@vger.kernel.org, regressions@leemhuis.info, torvalds@linux-foundation.org Subject: Re: [nfsd4] potentially hardware breaking regression in 4.14-rc and 4.13.11 Message-ID: <20171111024710.172301eb@alans-desktop> In-Reply-To: References: Organization: Intel Corporation X-Mailer: Claws Mail 3.15.1-dirty (GTK+ 2.24.31; x86_64-redhat-linux-gnu) MIME-Version: 1.0 Content-Type: text/plain; charset=US-ASCII Content-Transfer-Encoding: 7bit Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Wed, 8 Nov 2017 16:43:17 -0800 Patrick McLean wrote: > As of 4.13.11 (and also with 4.14-rc) we have an issue where when > serving nfs4 sometimes we get the following BUG. When this bug happens, > it usually also causes the motherboard to no longer POST until we > externally re-flash the BIOS (using the BMC web interface). If a > motherboard does not have an external way to flash the BIOS, this would > brick the hardware. If that is a production x86 system then you need to raise a large red flag with the vendor because it should not even be possible to splat the BIOS firmware on a modern PC by running even malicious OS code. Not only that but if it has a flaw, and you bisect down to create a reproducer then it's not going to take the bad guys very long to turn it into an interesting toy to run if they ever exploit a box with that board. Alan