From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1754782AbaIDQsR (ORCPT ); Thu, 4 Sep 2014 12:48:17 -0400 Received: from 251.110.2.81.in-addr.arpa ([81.2.110.251]:55527 "EHLO lxorguk.ukuu.org.uk" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1754309AbaIDQsQ (ORCPT ); Thu, 4 Sep 2014 12:48:16 -0400 Date: Thu, 4 Sep 2014 17:47:09 +0100 From: One Thousand Gnomes To: Ingo Molnar Cc: "H. Peter Anvin" , Linux Kernel Mailing List , Peter Zijlstra , Thomas Gleixner , Matthew Garrett Subject: Re: RFC: Tainting the kernel on raw I/O access Message-ID: <20140904174709.5bcb9b28@alan.etchedpixels.co.uk> In-Reply-To: <20140904050739.GA27112@gmail.com> References: <5407863B.9030608@intel.com> <20140904050739.GA27112@gmail.com> Organization: Intel Corporation X-Mailer: Claws Mail 3.9.3 (GTK+ 2.24.23; x86_64-pc-linux-gnu) MIME-Version: 1.0 Content-Type: text/plain; charset=US-ASCII Content-Transfer-Encoding: 7bit Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Thu, 4 Sep 2014 07:07:39 +0200 Ingo Molnar wrote: > > * H. Peter Anvin wrote: > > > In a meeting earlier today, we discussed MSR access and that it could be > > used to do bad things. The same applies to other forms of raw I/O > > (/dev/mem, /dev/port, ioperm, iopl, etc.) > > > > This is basically the same problem with which the secure boot people > > have been struggling. > > > > Peter Z. suggested we should taint the kernel on raw I/O access, and I > > tend to concur. > > Lets start with the 'only for developers and the crazy' > interfaces, like /dev/msr access, and extend it step by step? /dev/msr is used by standard distribution tools like powertop, and by chromeos power management layers like dptf. msr writes might fit the crazy book but I think you'd need to take a close look at the standard tools first This is the need a whitelist problem. Alan