Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1753949AbaLAOzY (ORCPT ); Mon, 1 Dec 2014 09:55:24 -0500 Received: from mail-la0-f53.google.com ([209.85.215.53]:59338 "EHLO mail-la0-f53.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1753618AbaLAOzX (ORCPT ); Mon, 1 Dec 2014 09:55:23 -0500 MIME-Version: 1.0 In-Reply-To: <5461EA6B.9020305@nod.at> References: <43c88012a4959cd427ab634906e697fbc524e847.1414604015.git.luto@amacapital.net> <20141110.211319.1983610686941713044.davem@davemloft.net> <5461EA6B.9020305@nod.at> From: Andy Lutomirski Date: Mon, 1 Dec 2014 06:55:01 -0800 Message-ID: Subject: Re: [PATCH v2] all arches, signal: Move restart_block to struct task_struct To: Richard Weinberger Cc: David Miller , Thomas Gleixner , "linux-kernel@vger.kernel.org" , Andrew Morton , linux-arch , Al Viro , richard -rw- weinberger , "H. Peter Anvin" , Ingo Molnar , Kees Cook Content-Type: text/plain; charset=UTF-8 Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Tue, Nov 11, 2014 at 2:52 AM, Richard Weinberger wrote: > Am 11.11.2014 um 03:13 schrieb David Miller: >> From: Andy Lutomirski >> Date: Mon, 10 Nov 2014 14:03:23 -0800 >> >>> On Wed, Oct 29, 2014 at 11:12 AM, Thomas Gleixner wrote: >>>> On Wed, 29 Oct 2014, Andy Lutomirski wrote: >>>> >>>>> If an attacker can cause a controlled kernel stack overflow, >>>>> overwriting the restart block is a very juicy exploit target. >>>>> Moving the restart block to struct task_struct prevents this >>>>> exploit. >>>>> >>>>> Note that there are other fields in thread_info that are also easy >>>>> targets, at least on some architectures. >>>>> >>>>> It's also a decent simplification, since the restart code is more or >>>>> less identical on all architectures. >>>> >>>> I think that's the most important change. Moving common stuff into >>>> common code. The side effect of slightly reducing the attack surface >>>> is nice, but as Al pointed out not really the big win here. >>> >>> Having gotten exactly zero feedback from any arch maintainer outside >>> of x86, am I supposed to pester people further? >> >> No objections wrt. sparc and if things break I'll help fix it. > > Same for UML. > Acked-by: Richard Weinberger akpm, do you consider this appropriate for either 3.19 or 3.20? If so, can you add it to the appropriate part of -mm? Thanks, Andy -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/