Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1758166Ab1EaTIq (ORCPT ); Tue, 31 May 2011 15:08:46 -0400 Received: from terminus.zytor.com ([198.137.202.10]:56433 "EHLO mail.zytor.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1752448Ab1EaTIo (ORCPT ); Tue, 31 May 2011 15:08:44 -0400 Message-ID: <4DE53C80.3070406@zytor.com> Date: Tue, 31 May 2011 12:07:44 -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.fc14 Thunderbird/3.1.10 MIME-Version: 1.0 To: Dan Rosenberg CC: Matthew Garrett , Tony Luck , linux-kernel@vger.kernel.org, kees.cook@canonical.com, davej@redhat.com, torvalds@linux-foundation.org, adobriyan@gmail.com, eranian@google.com, penberg@kernel.org, davem@davemloft.net, Arjan van de Ven , Valdis.Kletnieks@vt.edu, Andrew Morton , pageexec@freemail.hu, Ingo Molnar , Vivek Goyal Subject: Re: [RFC][PATCH] Randomize kernel base address on boot References: <1306269105.21443.20.camel@dan> <1306442367.2279.25.camel@dan> <20110531165252.GB8971@srcf.ucam.org> <4DE5360D.5070809@zytor.com> <20110531185122.GA11998@srcf.ucam.org> <1306868609.6317.25.camel@dan> In-Reply-To: <1306868609.6317.25.camel@dan> 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 Content-Length: 1082 Lines: 23 On 05/31/2011 12:03 PM, Dan Rosenberg wrote: > > Just for the record, I've put this patch on hold until there's some more > consensus about whether boot-time randomization of the physical kernel > address is the best approach. There are some other potential issues > that haven't been brought up yet publicly, such as the possibility of > local attackers performing cache timing attacks to find the kernel image > location at runtime, which may make traditional ASLR somewhat pointless > regardless (except in the case of remote attackers, I suppose). Perhaps > HPA's suggestion of further modularizing the kernel would have some > advantages in this regard. > I'm probably going to implement the whole-image randomization as an option in the Syslinux bootloader; it is a *lot* easier to do this correctly in the bootloader. -hpa -- 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/