Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1758431Ab1EZURK (ORCPT ); Thu, 26 May 2011 16:17:10 -0400 Received: from lennier.cc.vt.edu ([198.82.162.213]:42747 "EHLO lennier.cc.vt.edu" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1758135Ab1EZURI (ORCPT ); Thu, 26 May 2011 16:17:08 -0400 X-Mailer: exmh version 2.7.2 01/07/2005 with nmh-1.3-dev To: Vivek Goyal Cc: Dan Rosenberg , Tony Luck , linux-kernel@vger.kernel.org, davej@redhat.com, kees.cook@canonical.com, davem@davemloft.net, eranian@google.com, torvalds@linux-foundation.org, adobriyan@gmail.com, penberg@kernel.org, hpa@zytor.com, Arjan van de Ven , Andrew Morton , Ingo Molnar , pageexec@freemail.hu Subject: Re: [RFC][PATCH] Randomize kernel base address on boot In-Reply-To: Your message of "Thu, 26 May 2011 16:01:21 EDT." <20110526200121.GG29496@redhat.com> From: Valdis.Kletnieks@vt.edu References: <1306269105.21443.20.camel@dan> <20110526200121.GG29496@redhat.com> Mime-Version: 1.0 Content-Type: multipart/signed; boundary="==_Exmh_1306440965_8338P"; micalg=pgp-sha1; protocol="application/pgp-signature" Content-Transfer-Encoding: 7bit Date: Thu, 26 May 2011 16:16:05 -0400 Message-ID: <26081.1306440965@turing-police.cc.vt.edu> X-Mirapoint-Received-SPF: 198.82.161.152 auth3.smtp.vt.edu Valdis.Kletnieks@vt.edu 2 pass X-Mirapoint-IP-Reputation: reputation=neutral-1, source=Fixed, refid=n/a, actions=MAILHURDLE SPF TAG X-Junkmail: UCE(50) X-Junkmail-Status: score=50/50, host=steiner.cc.vt.edu X-Junkmail-Signature-Raw: score=bulk(0), refid=str=0001.0A020205.4DDEB50A.0070,ss=3,fgs=0, ip=0.0.0.0, so=2010-07-22 22:03:31, dmn=2009-09-10 00:05:08, mode=single engine X-Junkmail-IWF: false Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 1398 Lines: 37 --==_Exmh_1306440965_8338P Content-Type: text/plain; charset=us-ascii On Thu, 26 May 2011 16:01:21 EDT, Vivek Goyal said: > Also randomization of kernel load address at run time will probably have > some issues with crashkernel=X@Y address syntax. So far user knew what > address first kernel is booting from and user could speicy where to > reserve memory. Now it might happen that user specified some memory > to reserve and kernel decided to occupy that space resulting in failed > memory reservation for crash kernel. That is however fixable - the randomizer just needs to make sure it doesn't overlay the crashkernel= space, and the crashkernel needs to be started with a 'norandomize' parameter. If your threat model includes attacks on the crashkernel that randomizing will help with, you got bigger problems. ;) --==_Exmh_1306440965_8338P Content-Type: application/pgp-signature -----BEGIN PGP SIGNATURE----- Version: GnuPG v1.4.11 (GNU/Linux) Comment: Exmh version 2.5 07/13/2001 iD8DBQFN3rUFcC3lWbTT17ARAueeAKDRpW+QeeHoNcrfRR8K1iqOG4nT3gCfRtmF HLRf0l1y9u3J0GvJ4hfpM+4= =DkgC -----END PGP SIGNATURE----- --==_Exmh_1306440965_8338P-- -- 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/