From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1756369Ab1AKXcb (ORCPT ); Tue, 11 Jan 2011 18:32:31 -0500 Received: from smtp.outflux.net ([198.145.64.163]:59426 "EHLO smtp.outflux.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1754199Ab1AKXc3 (ORCPT ); Tue, 11 Jan 2011 18:32:29 -0500 Date: Tue, 11 Jan 2011 15:31:35 -0800 From: Kees Cook To: mingo@redhat.com, hpa@zytor.com, sliakh.lkml@gmail.com, jmorris@namei.org, linux-kernel@vger.kernel.org, rusty@rustcorp.com.au, torvalds@linux-foundation.org, ak@muc.de, davej@redhat.com, jiang@cs.ncsu.edu, arjan@infradead.org, castet.matthieu@free.fr, tglx@linutronix.de, sfr@canb.auug.org.au, mingo@elte.hu, Stefan Bader Subject: Re: [tip:x86/security] x86: Add NX protection for kernel data Message-ID: <20110111233135.GL4979@outflux.net> References: <4CE2F82E.60601@free.fr> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: Organization: Canonical X-HELO: www.outflux.net Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Thu, Nov 18, 2010 at 02:08:22PM +0000, tip-bot for Matthieu Castet wrote: > Commit-ID: 5bd5a452662bc37c54fb6828db1a3faf87e6511c > Gitweb: http://git.kernel.org/tip/5bd5a452662bc37c54fb6828db1a3faf87e6511c > Author: Matthieu Castet > AuthorDate: Tue, 16 Nov 2010 22:31:26 +0100 > Committer: Ingo Molnar > CommitDate: Thu, 18 Nov 2010 12:52:04 +0100 > > x86: Add NX protection for kernel data [I'd sent this in reply to the wrong patch before, resending now...] Hi, I was just shown this[1] on Xen from an Ubuntu bug report[2]. [ 1.230382] NX-protecting the kernel data: 3884k [ 1.231002] BUG: unable to handle kernel paging request at c1782ae0 ... [ 1.231145] Call Trace: [ 1.231152] [] ? __change_page_attr+0x2c1/0x370 [ 1.231161] [] ? __purge_vmap_area_lazy+0xc1/0x180 [ 1.231169] [] ? __change_page_attr_set_clr+0x4c/0xb0 [ 1.231176] [] ? change_page_attr_set_clr+0x128/0x300 [ 1.231183] [] ? __raw_callee_save_xen_restore_fl+0x6/0x8 [ 1.231192] [] ? vprintk+0x171/0x3f0 [ 1.231198] [] ? set_memory_nx+0x5f/0x70 Does Xen have different size page table allocations or something weird? -Kees [1] http://launchpadlibrarian.net/61853131/natty-failed-boot-ec2.txt [2] https://bugs.launchpad.net/ubuntu/+source/linux/+bug/699828 -- Kees Cook Ubuntu Security Team