From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1752306AbdJEU67 (ORCPT ); Thu, 5 Oct 2017 16:58:59 -0400 Received: from bombadil.infradead.org ([65.50.211.133]:55178 "EHLO bombadil.infradead.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1752268AbdJEU6z (ORCPT ); Thu, 5 Oct 2017 16:58:55 -0400 Date: Thu, 5 Oct 2017 13:58:52 -0700 From: Darren Hart To: Greg KH Cc: Mario.Limonciello@dell.com, pali.rohar@gmail.com, andy.shevchenko@gmail.com, linux-kernel@vger.kernel.org, platform-driver-x86@vger.kernel.org, luto@kernel.org, quasisec@google.com, rjw@rjwysocki.net, mjg59@google.com, hch@lst.de Subject: Re: [PATCH v4 12/14] platform/x86: wmi: create character devices when requested by drivers Message-ID: <20171005205852.GB12321@fury> References: <528c9a1ca4fa2f29aedbb37d3ed13c480ef093fc.1507156392.git.mario.limonciello@dell.com> <20171005071619.GA25960@kroah.com> <20171005154214.GB29347@kroah.com> <20171005155156.GZ10938@pali> <20171005162628.GA4993@kroah.com> <20171005173925.GD31452@fury> <20171005184728.GB9713@kroah.com> <750018cd00674782a55f2b50e8aef689@ausx13mpc120.AMER.DELL.COM> <20171005190948.GA21238@kroah.com> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20171005190948.GA21238@kroah.com> User-Agent: Mutt/1.8.0 (2017-02-23) Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Thu, Oct 05, 2017 at 09:09:48PM +0200, Greg KH wrote: > On Thu, Oct 05, 2017 at 07:03:24PM +0000, Mario.Limonciello@dell.com wrote: ... > > It's up to firmware to block the crazy stuff that you can put in a buffer. > > So userspace can pass any blob it wants to the firmware through this > interface and the kernel does not parse anything? How is that > "protected"? > > > > Again, I like my TPM to work, and I don't want a random rootkit exploit > > > to be able to destroy it :) > > > > I'd like to however point out you can't kill your TPM from this interface. > > On _your_ platform, can you guarantee it on any other platform? :) The dell-smbios-wmi driver won't load on any other platform. No character device is created for any other platform. When drivers are written for those other platforms for different WMI GUIDs, we need to review them. This driver not having MOF data should be the exception. We'll have more ability to inspect others. If drivers are submitted that don't look at the MOF data even through it is present, we should reject them. -- Darren Hart VMware Open Source Technology Center