From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1757411Ab2JAVAo (ORCPT ); Mon, 1 Oct 2012 17:00:44 -0400 Received: from atrey.karlin.mff.cuni.cz ([195.113.26.193]:60604 "EHLO atrey.karlin.mff.cuni.cz" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1755491Ab2JAVAh (ORCPT ); Mon, 1 Oct 2012 17:00:37 -0400 Date: Mon, 1 Oct 2012 23:00:34 +0200 From: Pavel Machek To: Matthew Garrett Cc: linux-kernel@vger.kernel.org, linux-security-module@vger.kernel.org, linux-efi@vger.kernel.org Subject: Re: [PATCH 02/11] PCI: Lock down BAR access in secure boot environments Message-ID: <20121001210034.GA21712@elf.ucw.cz> References: <1346774117-2277-1-git-send-email-mjg@redhat.com> <1346774117-2277-3-git-send-email-mjg@redhat.com> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <1346774117-2277-3-git-send-email-mjg@redhat.com> X-Warning: Reading this can be dangerous to your mental health. 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 Tue 2012-09-04 11:55:08, Matthew Garrett wrote: > Any hardware that can potentially generate DMA has to be locked down from > userspace in order to avoid it being possible for an attacker to cause > arbitrary kernel behaviour. Default to paranoid - in future we can > potentially relax this for sufficiently IOMMU-isolated devices. Would it be possible to 1) Use some better name than CAP_SECURE_FIRMWARE 2) Explain somewhere what the real requirements for "secure" boot are? "Secure" kernel may not boot unsigned kernel... what does it mean exactly? Suppose I launch full-screen window with dosemu running original windows installation on HDD, accessing raw disks, at nearly native speed. That is not something kernel should prevent, but it still allows me to do to do the stuff "secure" boot was designed to prevent... right? What is the exact threat "secure" boot should protect us against? Pavel -- (english) http://www.livejournal.com/~pavelmachek (cesky, pictures) http://atrey.karlin.mff.cuni.cz/~pavel/picture/horses/blog.html