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_PASS,URIBL_BLOCKED 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 9524EC28CF6 for ; Thu, 26 Jul 2018 15:22:50 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id 44A1E20685 for ; Thu, 26 Jul 2018 15:22:50 +0000 (UTC) DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org 44A1E20685 Authentication-Results: mail.kernel.org; dmarc=none (p=none dis=none) header.from=goodmis.org Authentication-Results: mail.kernel.org; spf=none smtp.mailfrom=linux-kernel-owner@vger.kernel.org Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1731644AbeGZQkH (ORCPT ); Thu, 26 Jul 2018 12:40:07 -0400 Received: from mail.kernel.org ([198.145.29.99]:34974 "EHLO mail.kernel.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1729801AbeGZQkH (ORCPT ); Thu, 26 Jul 2018 12:40:07 -0400 Received: from gandalf.local.home (cpe-66-24-56-78.stny.res.rr.com [66.24.56.78]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by mail.kernel.org (Postfix) with ESMTPSA id B28A920685; Thu, 26 Jul 2018 15:22:46 +0000 (UTC) Date: Thu, 26 Jul 2018 11:22:45 -0400 From: Steven Rostedt To: Mark Salyzyn Cc: linux-kernel@vger.kernel.org, Nick Desaulniers , Ingo Molnar , kernel-team@android.com, stable@vger.kernel.org Subject: Re: [PATCH] tracing: do not leak kernel addresses Message-ID: <20180726112245.3c1bf91d@gandalf.local.home> In-Reply-To: <11437c3e-5131-7190-c496-7b51eb7fcc2a@android.com> References: <20180725202238.165314-1-salyzyn@android.com> <20180725210717.3b807191@vmware.local.home> <11437c3e-5131-7190-c496-7b51eb7fcc2a@android.com> X-Mailer: Claws Mail 3.16.0 (GTK+ 2.24.32; x86_64-pc-linux-gnu) MIME-Version: 1.0 Content-Type: text/plain; charset=US-ASCII Content-Transfer-Encoding: 7bit Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Thu, 26 Jul 2018 08:14:08 -0700 Mark Salyzyn wrote: > Thank you Steve, much appreciated feedback, I have asked the security > developers to keep this in mind and come up with a correct fix. > > The correct fix that meets your guidelines would _not_ be suitable for > stable due to the invasiveness it sounds, only for the latest will such > a rework make sense. As such, the fix proposed in this patch is the only > one that meets the bar for stable patch simplicity, and merely(!) needs > to state that if the fix is taken, perf and trace are broken. > > Posting this patch publicly on the lists, that may never be applied, may > be the limit of our responsibility for a fix to stable kernel releases, > to be optionally applied by vendors concerned with this CVE criteria? > The patch breaks the code it touches. It makes it useless. If you want something for stable, add a command line parameter that just disables the creation of that file. Otherwise you will break usespace and that will be a definitely NAK from Linus, and for stable itself. This is a very minor security issue, and does not justify breaking userspace applications. I would be very upset if a new stable release broke both perf and trace-cmd's ability to read certain trace events. -- Steve