From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1751302Ab1E0RHe (ORCPT ); Fri, 27 May 2011 13:07:34 -0400 Received: from terminus.zytor.com ([198.137.202.10]:46587 "EHLO mail.zytor.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1750922Ab1E0RHd (ORCPT ); Fri, 27 May 2011 13:07:33 -0400 Message-ID: <4DDFDA22.205@zytor.com> Date: Fri, 27 May 2011 10:06:42 -0700 From: "H. Peter Anvin" User-Agent: Mozilla/5.0 (X11; U; Linux x86_64; en-US; rv:1.9.2.17) Gecko/20110428 Fedora/3.1.10-1.fc15 Thunderbird/3.1.10 MIME-Version: 1.0 To: Ingo Molnar CC: Linus Torvalds , "Rafael J. Wysocki" , Dan Rosenberg , Tony Luck , linux-kernel@vger.kernel.org, davej@redhat.com, kees.cook@canonical.com, davem@davemloft.net, eranian@google.com, adobriyan@gmail.com, penberg@kernel.org, Arjan van de Ven , Andrew Morton , Valdis.Kletnieks@vt.edu, pageexec@freemail.hu Subject: Re: [RFC][PATCH] Randomize kernel base address on boot References: <1306269105.21443.20.camel@dan> <201105270018.36835.rjw@sisk.pl> <20110527170045.GB4356@elte.hu> In-Reply-To: <20110527170045.GB4356@elte.hu> Content-Type: text/plain; charset=ISO-8859-1 Content-Transfer-Encoding: 7bit Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On 05/27/2011 10:00 AM, Ingo Molnar wrote: > > The problem with your relinking solution is that a local attacker can > easily figure out where the kernel is. So this does not protect > against the more common break-in scenario. > There is another issue with it: it doesn't actually solve the real problem other than suspend/resume, which is that the relocation agent needs to understand what the memory space looks like at the time of boot. I think something else we will need for this to be possible is initramfs decoding directly from highmem, since the hack we're currently using to deal with an initramfs/initrd located partly in highmem will break. -hpa