From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1947305Ab3BHXHF (ORCPT ); Fri, 8 Feb 2013 18:07:05 -0500 Received: from mail.skyhub.de ([78.46.96.112]:35374 "EHLO mail.skyhub.de" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1947176Ab3BHXHD (ORCPT ); Fri, 8 Feb 2013 18:07:03 -0500 Date: Sat, 9 Feb 2013 00:06:55 +0100 From: Borislav Petkov To: "H. Peter Anvin" Cc: Kees Cook , Matthew Garrett , LKML , Thomas Gleixner , Ingo Molnar , "x86@kernel.org" , "linux-efi@vger.kernel.org" , linux-security-module Subject: Re: [PATCH] x86: Lock down MSR writing in secure boot Message-ID: <20130208230655.GB28990@pd.tnic> Mail-Followup-To: Borislav Petkov , "H. Peter Anvin" , Kees Cook , Matthew Garrett , LKML , Thomas Gleixner , Ingo Molnar , "x86@kernel.org" , "linux-efi@vger.kernel.org" , linux-security-module References: <20130208191213.GA25081@www.outflux.net> <00780235-deac-4f80-b936-867834e05661@email.android.com> <5115553A.5000708@zytor.com> <1360355671.18083.18.camel@x230.lan> <51157C9C.6030501@zytor.com> MIME-Version: 1.0 Content-Type: text/plain; charset=utf-8 Content-Disposition: inline In-Reply-To: <51157C9C.6030501@zytor.com> User-Agent: Mutt/1.5.21 (2010-09-15) Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Fri, Feb 08, 2013 at 02:30:52PM -0800, H. Peter Anvin wrote: > Also, keep in mind that there is a very simple way to deny MSR access > completely, which is to not include the driver in your kernel (and not > allow module loading, but if you can load modules you can just load a > module to muck with whatever MSR you want.) I was contemplating that too. What is the use case of having msr.ko in a secure boot environment? Isn't that an all-no-tools, you-can't-do-sh*t-except-what-you're-explicitly-allowed-to environment which simply doesn't need to write MSRs in the first place? -- Regards/Gruss, Boris. Sent from a fat crate under my desk. Formatting is fine. --