From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1754065AbcEBPiP (ORCPT ); Mon, 2 May 2016 11:38:15 -0400 Received: from mail-io0-f169.google.com ([209.85.223.169]:35781 "EHLO mail-io0-f169.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751623AbcEBPiB (ORCPT ); Mon, 2 May 2016 11:38:01 -0400 Subject: Re: [PATCH 0/6] Intel Secure Guard Extensions To: Jarkko Sakkinen , Pavel Machek References: <1461605698-12385-1-git-send-email-jarkko.sakkinen@linux.intel.com> <20160426190009.GC8162@amd> <20160429201744.GD27821@intel.com> Cc: gregkh@linuxfoundation.org, Andy Lutomirski , Borislav Petkov , Boris Ostrovsky , "open list:STAGING SUBSYSTEM" , Ingo Molnar , Kristen Carlson Accardi , "open list:DOCUMENTATION" , open list , Mathias Krause , Thomas Gleixner , Wan Zongshun From: "Austin S. Hemmelgarn" Message-ID: <142feb98-3a97-0b00-0b17-b029fa2c637f@gmail.com> Date: Mon, 2 May 2016 11:37:52 -0400 User-Agent: Mozilla/5.0 (Windows NT 10.0; WOW64; rv:45.0) Gecko/20100101 Thunderbird/45.0 MIME-Version: 1.0 In-Reply-To: <20160429201744.GD27821@intel.com> Content-Type: text/plain; charset=windows-1252; format=flowed Content-Transfer-Encoding: 7bit Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On 2016-04-29 16:17, Jarkko Sakkinen wrote: > On Tue, Apr 26, 2016 at 09:00:10PM +0200, Pavel Machek wrote: >> On Mon 2016-04-25 20:34:07, Jarkko Sakkinen wrote: >>> Intel(R) SGX is a set of CPU instructions that can be used by >>> applications to set aside private regions of code and data. The code >>> outside the enclave is disallowed to access the memory inside the >>> enclave by the CPU access control. >>> >>> The firmware uses PRMRR registers to reserve an area of physical memory >>> called Enclave Page Cache (EPC). There is a hardware unit in the >>> processor called Memory Encryption Engine. The MEE encrypts and decrypts >>> the EPC pages as they enter and leave the processor package. >> >> What are non-evil use cases for this? > > I'm not sure what you mean by non-evil. > I would think that this should be pretty straightforward. Pretty much every security technology integrated in every computer in existence has the potential to be used by malware for various purposes. Based on a cursory look at SGX, it is pretty easy to figure out how to use this to hide arbitrary code from virus scanners and the OS itself unless you have some way to force everything to be a debug enclave, which entirely defeats the stated purpose of the extensions. I can see this being useful for tight embedded systems. On a desktop which I have full control of physical access to though, it's something I'd immediately turn off, because the risk of misuse is so significant (I've done so on my new Thinkpad L560 too, although that's mostly because Linux doesn't support it yet).