Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1753830AbYHLU5n (ORCPT ); Tue, 12 Aug 2008 16:57:43 -0400 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S1752166AbYHLU5e (ORCPT ); Tue, 12 Aug 2008 16:57:34 -0400 Received: from e2.ny.us.ibm.com ([32.97.182.142]:58081 "EHLO e2.ny.us.ibm.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1752165AbYHLU5c (ORCPT ); Tue, 12 Aug 2008 16:57:32 -0400 In-Reply-To: <20080812193031.GD18034@infradead.org> Subject: Re: [PATCH 1/4] integrity: TPM internel kernel interface To: Christoph Hellwig Cc: linux-kernel@vger.kernel.org, linux-security-module@vger.kernel.org, Mimi Zohar X-Mailer: Lotus Notes Release 7.0 HF277 June 21, 2006 Message-ID: From: Kenneth Goldman Date: Tue, 12 Aug 2008 16:57:31 -0400 X-MIMETrack: Serialize by Router on D01ML604/01/M/IBM(Build V85_M1_05262008|May 26, 2008) at 08/12/2008 16:57:31 MIME-Version: 1.0 Content-type: text/plain; charset=US-ASCII Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 1320 Lines: 33 Christoph Hellwig wrote on 08/12/2008 03:30:31 PM: > On Mon, Aug 11, 2008 at 05:13:51PM -0400, Mimi Zohar wrote: > > > > I assume the concern here is that between looking up the chip and actually > > > > using the chip, the TPM chip is disabled/deactivated. Based on > > discussions > > with Kenneth Goldman, the TCG main specification part2: structures, > > require > > that even if the TPM is disabled/deactivated, the command to extend the > > PCR > > will succeed, but the command to read the PCR will fail with an > > appropriate > > error code. > > And what happens when the chip simply goes away due to a hotplug action? > Or not even the actual chip goes away but just the chip driver and you > now dereference freed memory? Being a TCG/TPM person, I can only address the first question. The intent is that the TPM is soldered to the planar/motherboard (the TCG uses the phrase "bound to the platform"). I can't imagine any manufacturer designing a pluggable TPM. It would subvert PCR measurements and thus attestation, data sealing, etc. -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/