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=-2.5 required=3.0 tests=HEADER_FROM_DIFFERENT_DOMAINS, MAILING_LIST_MULTI,SPF_PASS,USER_AGENT_MUTT 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 5A98CC32789 for ; Tue, 20 Nov 2018 23:13:26 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id BD11B21479 for ; Tue, 20 Nov 2018 23:13:26 +0000 (UTC) DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org BD11B21479 Authentication-Results: mail.kernel.org; dmarc=fail (p=none dis=none) header.from=linux.intel.com Authentication-Results: mail.kernel.org; spf=none smtp.mailfrom=linux-security-module-owner@vger.kernel.org Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1725938AbeKUJpE (ORCPT ); Wed, 21 Nov 2018 04:45:04 -0500 Received: from mga02.intel.com ([134.134.136.20]:13077 "EHLO mga02.intel.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1725900AbeKUJpE (ORCPT ); Wed, 21 Nov 2018 04:45:04 -0500 X-Amp-Result: UNSCANNABLE X-Amp-File-Uploaded: False Received: from fmsmga002.fm.intel.com ([10.253.24.26]) by orsmga101.jf.intel.com with ESMTP/TLS/DHE-RSA-AES256-GCM-SHA384; 20 Nov 2018 15:13:25 -0800 X-ExtLoop1: 1 X-IronPort-AV: E=Sophos;i="5.56,258,1539673200"; d="scan'208";a="106326782" Received: from drhumphr-mobl.ger.corp.intel.com (HELO localhost) ([10.249.254.165]) by fmsmga002.fm.intel.com with ESMTP; 20 Nov 2018 15:13:21 -0800 Date: Wed, 21 Nov 2018 01:13:20 +0200 From: Jarkko Sakkinen To: James Bottomley Cc: linux-integrity@vger.kernel.org, linux-security-module@vger.kernel.org, monty.wiseman@ge.com, Monty Wiseman , Matthew Garrett Subject: Re: Documenting the proposal for TPM 2.0 security in the face of bus interposer attacks Message-ID: <20181120231320.GI8391@linux.intel.com> References: <1542648844.2910.9.camel@HansenPartnership.com> <20181120111049.GC14594@linux.intel.com> <20181120124116.GA8813@linux.intel.com> <1542734743.2814.31.camel@HansenPartnership.com> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <1542734743.2814.31.camel@HansenPartnership.com> Organization: Intel Finland Oy - BIC 0357606-4 - Westendinkatu 7, 02160 Espoo User-Agent: Mutt/1.10.1 (2018-07-13) Sender: owner-linux-security-module@vger.kernel.org Precedence: bulk List-ID: On Tue, Nov 20, 2018 at 09:25:43AM -0800, James Bottomley wrote: > On Tue, 2018-11-20 at 14:41 +0200, Jarkko Sakkinen wrote: > > On Tue, Nov 20, 2018 at 01:10:49PM +0200, Jarkko Sakkinen wrote: > > > This is basically rewrite of TPM genie paper with extras. Maybe > > > just shorten it to include the proposed architecture and point to > > > the TPM Genie paper (which is not in the references at all ATM). > > > > > > The way I see it the data validation is way more important than > > > protecting against physical interposer to be frank. > > > > > > The attack scenario would require to open the damn device. For > > > laptop that would leave physical marks (i.e. evil maid). In a data > > > center with armed guards I would wish you good luck accomplishing > > > it. It is not anything like sticking a USB stick and run. > > > > > > We can take a fix into Linux with a clean implementation but it > > > needs to be an opt-in feature because not all users will want to > > > use it. > > > > Someone (might have been either Mimi or David Howells but cannot > > recall) correctly pointed out at LSS 2018 that you could just as > > easily spy and corrupt RAM if you have a time window to perform this > > type of attack. > > Not using the simple plug in on the TPM bus, you can't. The point is > basically the difference in the technology: the interposer is a simple, > easy to construct, plugin; a RAM spy is a huge JTAG thing that would be > hard even to fit into a modern thin laptop, let alone extremely > difficult to build. Why you wouldn't use DMA to spy the RAM? /Jarkko