From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S934376Ab3CTBAj (ORCPT ); Tue, 19 Mar 2013 21:00:39 -0400 Received: from terminus.zytor.com ([198.137.202.10]:42238 "EHLO mail.zytor.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1755874Ab3CTBAh (ORCPT ); Tue, 19 Mar 2013 21:00:37 -0400 Message-ID: <51490A22.1080908@zytor.com> Date: Tue, 19 Mar 2013 18:00:18 -0700 From: "H. Peter Anvin" User-Agent: Mozilla/5.0 (X11; Linux x86_64; rv:17.0) Gecko/20130311 Thunderbird/17.0.4 MIME-Version: 1.0 To: Matthew Garrett CC: linux-kernel@vger.kernel.org, linux-security-module@vger.kernel.org, linux-efi@vger.kernel.org, kexec@lists.infradead.org, linux-pci@vger.kernel.org Subject: Re: [PATCH 06/12] x86: Require CAP_COMPROMISE_KERNEL for IO port access References: <1363642353-30749-1-git-send-email-matthew.garrett@nebula.com> <1363642353-30749-6-git-send-email-matthew.garrett@nebula.com> In-Reply-To: <1363642353-30749-6-git-send-email-matthew.garrett@nebula.com> X-Enigmail-Version: 1.5.1 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 7bit Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On 03/18/2013 02:32 PM, 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. > Again, if you are going to do this, just kill bloody RAWIO. Quite frankly saying brainfucked SCSI drivers have abused it doesn't hold water, because as far as you know those same commands can trigger arbitrary DMA activity. -hpa From mboxrd@z Thu Jan 1 00:00:00 1970 Return-path: Received: from terminus.zytor.com ([2001:1868:205::10] helo=mail.zytor.com) by merlin.infradead.org with esmtps (Exim 4.80.1 #2 (Red Hat Linux)) id 1UI7OL-00039J-Jh for kexec@lists.infradead.org; Wed, 20 Mar 2013 01:00:34 +0000 Message-ID: <51490A22.1080908@zytor.com> Date: Tue, 19 Mar 2013 18:00:18 -0700 From: "H. Peter Anvin" MIME-Version: 1.0 Subject: Re: [PATCH 06/12] x86: Require CAP_COMPROMISE_KERNEL for IO port access References: <1363642353-30749-1-git-send-email-matthew.garrett@nebula.com> <1363642353-30749-6-git-send-email-matthew.garrett@nebula.com> In-Reply-To: <1363642353-30749-6-git-send-email-matthew.garrett@nebula.com> List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: 7bit Sender: "kexec" Errors-To: kexec-bounces+dwmw2=infradead.org@lists.infradead.org To: Matthew Garrett Cc: linux-pci@vger.kernel.org, linux-security-module@vger.kernel.org, linux-efi@vger.kernel.org, kexec@lists.infradead.org, linux-kernel@vger.kernel.org On 03/18/2013 02:32 PM, 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. > Again, if you are going to do this, just kill bloody RAWIO. Quite frankly saying brainfucked SCSI drivers have abused it doesn't hold water, because as far as you know those same commands can trigger arbitrary DMA activity. -hpa _______________________________________________ kexec mailing list kexec@lists.infradead.org http://lists.infradead.org/mailman/listinfo/kexec