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=-3.0 required=3.0 tests=HEADER_FROM_DIFFERENT_DOMAINS, MAILING_LIST_MULTI,SPF_PASS,URIBL_BLOCKED,USER_AGENT_NEOMUTT autolearn=ham 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 E0F3EC43387 for ; Thu, 17 Jan 2019 10:59:10 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id B8AFA20657 for ; Thu, 17 Jan 2019 10:59:10 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1728605AbfAQK7I (ORCPT ); Thu, 17 Jan 2019 05:59:08 -0500 Received: from bastet.se.axis.com ([195.60.68.11]:44592 "EHLO bastet.se.axis.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1728241AbfAQK7I (ORCPT ); Thu, 17 Jan 2019 05:59:08 -0500 Received: from localhost (localhost [127.0.0.1]) by bastet.se.axis.com (Postfix) with ESMTP id 0847B1858B; Thu, 17 Jan 2019 11:59:06 +0100 (CET) X-Axis-User: NO X-Axis-NonUser: YES X-Virus-Scanned: Debian amavisd-new at bastet.se.axis.com Received: from bastet.se.axis.com ([IPv6:::ffff:127.0.0.1]) by localhost (bastet.se.axis.com [::ffff:127.0.0.1]) (amavisd-new, port 10024) with LMTP id dl9O8wN-YWCV; Thu, 17 Jan 2019 11:59:04 +0100 (CET) Received: from boulder02.se.axis.com (boulder02.se.axis.com [10.0.8.16]) by bastet.se.axis.com (Postfix) with ESMTPS id 9A4CB180EA; Thu, 17 Jan 2019 11:59:04 +0100 (CET) Received: from boulder02.se.axis.com (unknown [127.0.0.1]) by IMSVA (Postfix) with ESMTP id 890151A06B; Thu, 17 Jan 2019 11:59:04 +0100 (CET) Received: from boulder02.se.axis.com (unknown [127.0.0.1]) by IMSVA (Postfix) with ESMTP id 7D5B31A067; Thu, 17 Jan 2019 11:59:04 +0100 (CET) Received: from thoth.se.axis.com (unknown [10.0.2.173]) by boulder02.se.axis.com (Postfix) with ESMTP; Thu, 17 Jan 2019 11:59:04 +0100 (CET) Received: from lnxartpec.se.axis.com (lnxartpec.se.axis.com [10.88.4.9]) by thoth.se.axis.com (Postfix) with ESMTP id 7155B1A05; Thu, 17 Jan 2019 11:59:04 +0100 (CET) Received: by lnxartpec.se.axis.com (Postfix, from userid 10564) id 6845180B46; Thu, 17 Jan 2019 11:59:04 +0100 (CET) Date: Thu, 17 Jan 2019 11:59:04 +0100 From: Vincent Whitchurch To: Kees Cook Cc: Andrew Morton , "Luis R. Rodriguez" , LKML Subject: Re: [PATCH] sysctl: Add panic-fatal-signals Message-ID: <20190117105903.dilzmdlqtyiogpo3@axis.com> References: <20190116125422.19643-1-vincent.whitchurch@axis.com> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: User-Agent: NeoMutt/20170113 (1.7.2) X-TM-AS-GCONF: 00 Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Wed, Jan 16, 2019 at 09:06:18AM -0800, Kees Cook wrote: > On Wed, Jan 16, 2019 at 4:54 AM Vincent Whitchurch > wrote: > > Add a sysctl which asks the kernel to panic when any userspace process > > receives a fatal signal which would trigger a core dump. This has > > proven to be quite useful when debugging problems seen during testing of > > embedded systems: When combined with kernel core dumps (saved due to > > the panic), it allows easier debugging of crashes which have their > > origin in system-wide problems such as buggy drivers or other kernel or > > hardware-related issues. > > > > The crashing process's core dump can be extracted from the kernel core > > dump using tools such as the crash utility's gcore extension. > > Whoa. That's intense. :) "Insane" is the word I used myself in an earlier draft of the commit message. :) > If you have a use-case for it, then I guess I > can't complain. Given that this is an instant DoS for a system that > isn't expecting it, I do wonder if it should live behind a CONFIG or > something to make it available only when really wanted? Sure, I can put it behind a "depends on EXPERT" config option. Distros and the like should have no reason to provide access to such a sysctl.