Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1752380AbaKKCNZ (ORCPT ); Mon, 10 Nov 2014 21:13:25 -0500 Received: from shards.monkeyblade.net ([149.20.54.216]:51219 "EHLO shards.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751837AbaKKCNX (ORCPT ); Mon, 10 Nov 2014 21:13:23 -0500 Date: Mon, 10 Nov 2014 21:13:19 -0500 (EST) Message-Id: <20141110.211319.1983610686941713044.davem@davemloft.net> To: luto@amacapital.net Cc: tglx@linutronix.de, linux-kernel@vger.kernel.org, akpm@linux-foundation.org, linux-arch@vger.kernel.org, viro@zeniv.linux.org.uk, richard.weinberger@gmail.com, hpa@zytor.com, mingo@kernel.org, keescook@chromium.org Subject: Re: [PATCH v2] all arches, signal: Move restart_block to struct task_struct From: David Miller In-Reply-To: References: <43c88012a4959cd427ab634906e697fbc524e847.1414604015.git.luto@amacapital.net> X-Mailer: Mew version 6.6 on Emacs 24.3 / Mule 6.0 (HANACHIRUSATO) 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-4.5.7 (shards.monkeyblade.net [149.20.54.216]); Mon, 10 Nov 2014 18:13:22 -0800 (PST) Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org 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. -- 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/