From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S935754Ab3DIS5F (ORCPT ); Tue, 9 Apr 2013 14:57:05 -0400 Received: from terminus.zytor.com ([198.137.202.10]:51053 "EHLO mail.zytor.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S935256Ab3DIS5D (ORCPT ); Tue, 9 Apr 2013 14:57:03 -0400 Message-ID: <51646302.2030608@zytor.com> Date: Tue, 09 Apr 2013 11:50:42 -0700 From: "H. Peter Anvin" User-Agent: Mozilla/5.0 (X11; Linux x86_64; rv:17.0) Gecko/20130311 Thunderbird/17.0.4 MIME-Version: 1.0 To: Kees Cook CC: "kernel-hardening@lists.openwall.com" , Ingo Molnar , LKML , "x86@kernel.org" , Konrad Rzeszutek Wilk , Jeremy Fitzhardinge , Marcelo Tosatti , Alex Shi , Borislav Petkov , Alexander Duyck , Frederic Weisbecker , Steven Rostedt , "Paul E. McKenney" , "xen-devel@lists.xensource.com" , "virtualization@lists.linux-foundation.org" , Dan Rosenberg , Julien Tinnes , Will Drewry , Eric Northup Subject: Re: [kernel-hardening] Re: [PATCH] x86: make IDT read-only References: <20130408224328.GA17641@www.outflux.net> <51634935.9010905@zytor.com> <51645D6F.7070705@zytor.com> <51646054.3090509@zytor.com> In-Reply-To: X-Enigmail-Version: 1.5.1 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 7bit Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On 04/09/2013 11:46 AM, Kees Cook wrote: > > Ah-ha! Yes, I see now when comparing the debug/kernel_page_tables > reports. It's just the High Kernel Mapping that we care about. > Addresses outside that range are less of a leak. Excellent, then GDT > may not be a problem. Whew. > It does beg the question if we need to randomize kmalloc... which could have issues by itself. -hpa -- H. Peter Anvin, Intel Open Source Technology Center I work for Intel. I don't speak on their behalf.