From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org X-Spam-Level: X-Spam-Status: No, score=-4.0 required=3.0 tests=HEADER_FROM_DIFFERENT_DOMAINS, MAILING_LIST_MULTI,SIGNED_OFF_BY,SPF_PASS,URIBL_BLOCKED autolearn=unavailable autolearn_force=no version=3.4.0 Received: from mail.kernel.org (mail.kernel.org [198.145.29.99]) by smtp.lore.kernel.org (Postfix) with ESMTP id 8AE46C10F05 for ; Thu, 4 Apr 2019 07:49:08 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id 5BC9C20882 for ; Thu, 4 Apr 2019 07:49:08 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1727263AbfDDHtH (ORCPT ); Thu, 4 Apr 2019 03:49:07 -0400 Received: from Galois.linutronix.de ([146.0.238.70]:43766 "EHLO Galois.linutronix.de" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1725904AbfDDHtG (ORCPT ); Thu, 4 Apr 2019 03:49:06 -0400 Received: from p5492e2fc.dip0.t-ipconnect.de ([84.146.226.252] helo=nanos) by Galois.linutronix.de with esmtpsa (TLS1.2:DHE_RSA_AES_256_CBC_SHA256:256) (Exim 4.80) (envelope-from ) id 1hBx7P-0000P7-3J; Thu, 04 Apr 2019 09:49:03 +0200 Date: Thu, 4 Apr 2019 09:49:02 +0200 (CEST) From: Thomas Gleixner To: Matthew Garrett cc: jmorris@namei.org, linux-security-module@vger.kernel.org, linux-kernel@vger.kernel.org, dhowells@redhat.com, linux-api@vger.kernel.org, luto@kernel.org, Matthew Garrett , Matthew Garrett , x86@kernel.org Subject: Re: [PATCH V32 11/27] x86: Lock down IO port access when the kernel is locked down In-Reply-To: <20190404003249.14356-12-matthewgarrett@google.com> Message-ID: References: <20190404003249.14356-1-matthewgarrett@google.com> <20190404003249.14356-12-matthewgarrett@google.com> User-Agent: Alpine 2.21 (DEB 202 2017-01-01) MIME-Version: 1.0 Content-Type: text/plain; charset=US-ASCII X-Linutronix-Spam-Score: -1.0 X-Linutronix-Spam-Level: - X-Linutronix-Spam-Status: No , -1.0 points, 5.0 required, ALL_TRUSTED=-1,SHORTCIRCUIT=-0.0001 Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Wed, 3 Apr 2019, Matthew Garrett wrote: > From: Matthew Garrett > > 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. > > This also implicitly locks down the KDADDIO, KDDELIO, KDENABIO and > KDDISABIO console ioctls. > > Signed-off-by: Matthew Garrett > Signed-off-by: David Howells Reviewed-by: Thomas Gleixner