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=-1.0 required=3.0 tests=HEADER_FROM_DIFFERENT_DOMAINS, MAILING_LIST_MULTI,SPF_PASS 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 C7E3DC64EB1 for ; Thu, 6 Dec 2018 18:07:44 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id 92C3120850 for ; Thu, 6 Dec 2018 18:07:44 +0000 (UTC) DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org 92C3120850 Authentication-Results: mail.kernel.org; dmarc=none (p=none dis=none) header.from=huawei.com Authentication-Results: mail.kernel.org; spf=none smtp.mailfrom=linux-kernel-owner@vger.kernel.org Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1726030AbeLFSHn (ORCPT ); Thu, 6 Dec 2018 13:07:43 -0500 Received: from lhrrgout.huawei.com ([185.176.76.210]:32802 "EHLO huawei.com" rhost-flags-OK-OK-OK-FAIL) by vger.kernel.org with ESMTP id S1725898AbeLFSHn (ORCPT ); Thu, 6 Dec 2018 13:07:43 -0500 Received: from LHREML711-CAH.china.huawei.com (unknown [172.18.7.108]) by Forcepoint Email with ESMTP id A609DD4B967B3; Thu, 6 Dec 2018 18:07:39 +0000 (GMT) Received: from [10.204.65.144] (10.204.65.144) by smtpsuk.huawei.com (10.201.108.34) with Microsoft SMTP Server (TLS) id 14.3.408.0; Thu, 6 Dec 2018 18:07:35 +0000 Subject: Re: [PATCH v6 6/7] tpm: ensure that the output of PCR read contains the correct digest size To: Jarkko Sakkinen CC: , , , , , , References: <20181204082138.24600-1-roberto.sassu@huawei.com> <20181204082138.24600-7-roberto.sassu@huawei.com> <20181205000910.GE1233@linux.intel.com> <20181205004643.GA26578@linux.intel.com> From: Roberto Sassu Message-ID: Date: Thu, 6 Dec 2018 19:07:34 +0100 User-Agent: Mozilla/5.0 (Windows NT 10.0; WOW64; rv:60.0) Gecko/20100101 Thunderbird/60.3.0 MIME-Version: 1.0 In-Reply-To: <20181205004643.GA26578@linux.intel.com> Content-Type: text/plain; charset="utf-8"; format=flowed Content-Language: en-US Content-Transfer-Encoding: 7bit X-Originating-IP: [10.204.65.144] X-CFilter-Loop: Reflected Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On 12/5/2018 1:46 AM, Jarkko Sakkinen wrote: > On Tue, Dec 04, 2018 at 04:09:10PM -0800, Jarkko Sakkinen wrote: >> On Tue, Dec 04, 2018 at 09:21:37AM +0100, Roberto Sassu wrote: >>> out = (struct tpm2_pcr_read_out *)&buf.data[TPM_HEADER_SIZE]; >>> digest_size = be16_to_cpu(out->digest_size); >>> - if (digest_size > sizeof(digest->digest)) { >>> + if (digest_size > sizeof(digest->digest) || >>> + (!digest_size_ptr && digest_size != expected_digest_size)) { >>> rc = -EINVAL; >>> goto out; >>> } >> >> Just noticed this but you must squash 4-6 because applying only >> previous commits will result a broken tree. It will be much bigger >> commit but won't be broken. >> >> I think you should also feed min_rsp_body_length as you should be >> able to precalculate. >> >> Last time I was asking why this isn't a bug fix. It is even for >> the existing code. The existing code should have a bug fix that >> checks that the received digest size so that it is the expected >> SHA1 size before we can apply this commit. > > My bad. This is not the same deal as the code because in the old code we > always copy a constant block. Here we use the variable as parameter for > memcpy() so it is better to check the size. You can ignore the last > paragraph completely. Sorry, had to double check this one. > > There is no need to do any type of bug fix for the current tree. > > Still 4-6 need to be squashed in order to not put purposely the tree > into broken state. Ok. I keep the description of 5, and add few details from 4 and 6. Roberto > /Jarko > -- HUAWEI TECHNOLOGIES Duesseldorf GmbH, HRB 56063 Managing Director: Bo PENG, Jian LI, Yanli SHI