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=-5.5 required=3.0 tests=HEADER_FROM_DIFFERENT_DOMAINS, MAILING_LIST_MULTI,SIGNED_OFF_BY,SPF_PASS,URIBL_BLOCKED,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 C07F1C43441 for ; Mon, 19 Nov 2018 14:34:13 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id 8434020831 for ; Mon, 19 Nov 2018 14:34:13 +0000 (UTC) DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org 8434020831 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 S1729376AbeKTA5s (ORCPT ); Mon, 19 Nov 2018 19:57:48 -0500 Received: from mga05.intel.com ([192.55.52.43]:23645 "EHLO mga05.intel.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1729365AbeKTA5s (ORCPT ); Mon, 19 Nov 2018 19:57:48 -0500 X-Amp-Result: UNKNOWN X-Amp-Original-Verdict: FILE UNKNOWN X-Amp-File-Uploaded: False Received: from fmsmga003.fm.intel.com ([10.253.24.29]) by fmsmga105.fm.intel.com with ESMTP/TLS/DHE-RSA-AES256-GCM-SHA384; 19 Nov 2018 06:34:00 -0800 X-ExtLoop1: 1 X-IronPort-AV: E=Sophos;i="5.56,252,1539673200"; d="scan'208";a="97444961" Received: from tmuluk-mobl4.ger.corp.intel.com (HELO localhost) ([10.249.254.135]) by FMSMGA003.fm.intel.com with ESMTP; 19 Nov 2018 06:33:58 -0800 Date: Mon, 19 Nov 2018 16:33:57 +0200 From: Jarkko Sakkinen To: Roberto Sassu Cc: zohar@linux.ibm.com, david.safford@ge.com, monty.wiseman@ge.com, linux-integrity@vger.kernel.org, linux-security-module@vger.kernel.org, linux-kernel@vger.kernel.org, silviu.vlasceanu@huawei.com, stable@vger.kernel.org Subject: Re: [PATCH v5 6/7] tpm: ensure that the output of PCR read contains the correct digest size Message-ID: <20181119143357.GG8755@linux.intel.com> References: <20181114153108.12907-1-roberto.sassu@huawei.com> <20181114153108.12907-7-roberto.sassu@huawei.com> <20181116134153.GD4163@linux.intel.com> <05c7c936-da58-f386-0a43-69e96d6e18a8@huawei.com> <20181118073207.GC5897@linux.intel.com> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: 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 Mon, Nov 19, 2018 at 09:14:00AM +0100, Roberto Sassu wrote: > On 11/18/2018 8:32 AM, Jarkko Sakkinen wrote: > > On Fri, Nov 16, 2018 at 05:06:48PM +0100, Roberto Sassu wrote: > > > On 11/16/2018 2:41 PM, Jarkko Sakkinen wrote: > > > > On Wed, Nov 14, 2018 at 04:31:07PM +0100, Roberto Sassu wrote: > > > > > This patch protects against data corruption that could happen in the bus, > > > > > by checking that that the digest size returned by the TPM during a PCR read > > > > > matches the size of the algorithm passed to tpm2_pcr_read(). > > > > > > > > > > This check is performed after information about the PCR banks has been > > > > > retrieved. > > > > > > > > > > Signed-off-by: Roberto Sassu > > > > > Reviewed-by: Jarkko Sakkinen > > > > > Cc: stable@vger.kernel.org > > > > > > > > Missing fixes tag. > > > > > > Before this patch set, tpm2_pcr_extend() always copied 20 bytes from the > > > output sent by the TPM. > > > > > > Roberto > > > > Aah, right, of course. Well the patch set is ATM somewhat broken because > > this would require a fixes tag that points to a patch insdie the patch > > set. > > > > Probably good way to fix the issue is to just merge this with the > > earlier commit. > > Unfortunately, it is not possible. The exact digest size has been > introduced with patch 5/7. I put this in simple terms: if I merge 5/7 the driver will be broken. Any commit in the patch set should not leave the tree in broken state. That implies that 5/7 and 6/7 cannot be separate commits. /Jarkko