Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1751612Ab1E0Sos (ORCPT ); Fri, 27 May 2011 14:44:48 -0400 Received: from smtp.outflux.net ([198.145.64.163]:52823 "EHLO smtp.outflux.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1750935Ab1E0Sor (ORCPT ); Fri, 27 May 2011 14:44:47 -0400 Date: Fri, 27 May 2011 11:43:58 -0700 From: Kees Cook To: Ingo Molnar Cc: Linus Torvalds , Dan Rosenberg , "Rafael J. Wysocki" , Tony Luck , linux-kernel@vger.kernel.org, davej@redhat.com, davem@davemloft.net, eranian@google.com, adobriyan@gmail.com, penberg@kernel.org, hpa@zytor.com, Arjan van de Ven , Andrew Morton , Valdis.Kletnieks@vt.edu, pageexec@freemail.hu Subject: Re: [RFC][PATCH] Randomize kernel base address on boot Message-ID: <20110527184358.GA19633@outflux.net> References: <1306269105.21443.20.camel@dan> <201105270018.36835.rjw@sisk.pl> <20110527170045.GB4356@elte.hu> <1306516230.3339.17.camel@dan> <20110527171611.GE4356@elte.hu> <20110527174644.GG4356@elte.hu> <20110527181724.GA6485@elte.hu> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20110527181724.GA6485@elte.hu> Organization: Canonical X-HELO: www.outflux.net Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 1316 Lines: 32 On Fri, May 27, 2011 at 08:17:24PM +0200, Ingo Molnar wrote: > - Boot time dynamic randomization allows randomization of 'mass > install' systems, where the same image is used, to still be > randomized: for example a million phones all with the same Flash > ROM image and no 'install' performed at all on them. > > With static randomization these systems will all have the same > kernel addresses. > > - Boot time dynamic randomization allows read-only systems to still > be randomized: for example internet cafes that use some popular > pre-packaged kiosk-mode live-DVD. They probably wont bother > randomizing and relinking the ISOs per machine and burning per > machine DVDs ... These 2 points are pretty significant, IMO. And frankly, distros almost fall into these categories already. IIUC, a distro would need to ship all of the .o files from each config of the kernel they ship so each system could do the relinking. That's not a small foot print to suddenly add to base installs. -Kees -- Kees Cook Ubuntu Security Team -- 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/