From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1757311Ab2IDQLT (ORCPT ); Tue, 4 Sep 2012 12:11:19 -0400 Received: from lxorguk.ukuu.org.uk ([81.2.110.251]:43340 "EHLO lxorguk.ukuu.org.uk" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1750777Ab2IDQLR (ORCPT ); Tue, 4 Sep 2012 12:11:17 -0400 Date: Tue, 4 Sep 2012 17:16:03 +0100 From: Alan Cox To: Matthew Garrett Cc: linux-kernel@vger.kernel.org, linux-security-module@vger.kernel.org, linux-efi@vger.kernel.org Subject: Re: [PATCH 03/11] x86: Lock down IO port access in secure boot environments Message-ID: <20120904171603.3ccb5891@pyramind.ukuu.org.uk> In-Reply-To: <1346774117-2277-4-git-send-email-mjg@redhat.com> References: <1346774117-2277-1-git-send-email-mjg@redhat.com> <1346774117-2277-4-git-send-email-mjg@redhat.com> X-Mailer: Claws Mail 3.8.0 (GTK+ 2.24.8; x86_64-redhat-linux-gnu) Face: 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 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 Tue, 4 Sep 2012 11:55:09 -0400 Matthew Garrett wrote: > IO port access would permit users to gain access to PCI configuration > registers, which in turn (on a lot of hardware) give access to MMIO register > space. This would potentially permit root to trigger arbitrary DMA, so lock > it down by default. You've missed a load of others, all over the kernel, let alone getting into devices with other paths to firmware reprogramming of which there are many. You need to enforce signing on request_firmware for example, and sign every firmware.