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=-0.8 required=3.0 tests=HEADER_FROM_DIFFERENT_DOMAINS, MAILING_LIST_MULTI,SPF_PASS,URIBL_BLOCKED autolearn=ham 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 B5870C43334 for ; Wed, 5 Sep 2018 13:16:10 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id 7AD4D206BA for ; Wed, 5 Sep 2018 13:16:10 +0000 (UTC) DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org 7AD4D206BA Authentication-Results: mail.kernel.org; dmarc=fail (p=none dis=none) header.from=linux.vnet.ibm.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 S1727706AbeIERqW (ORCPT ); Wed, 5 Sep 2018 13:46:22 -0400 Received: from mx0b-001b2d01.pphosted.com ([148.163.158.5]:41172 "EHLO mx0a-001b2d01.pphosted.com" rhost-flags-OK-OK-OK-FAIL) by vger.kernel.org with ESMTP id S1725868AbeIERqW (ORCPT ); Wed, 5 Sep 2018 13:46:22 -0400 Received: from pps.filterd (m0098417.ppops.net [127.0.0.1]) by mx0a-001b2d01.pphosted.com (8.16.0.22/8.16.0.22) with SMTP id w85DEI0o058413 for ; Wed, 5 Sep 2018 09:16:07 -0400 Received: from e17.ny.us.ibm.com (e17.ny.us.ibm.com [129.33.205.207]) by mx0a-001b2d01.pphosted.com with ESMTP id 2mae68w8f5-1 (version=TLSv1.2 cipher=AES256-GCM-SHA384 bits=256 verify=NOT) for ; Wed, 05 Sep 2018 09:16:06 -0400 Received: from localhost by e17.ny.us.ibm.com with IBM ESMTP SMTP Gateway: Authorized Use Only! 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Violators will be prosecuted; (version=TLSv1/SSLv3 cipher=AES256-GCM-SHA384 bits=256/256) Wed, 5 Sep 2018 09:16:02 -0400 Received: from b01ledav003.gho.pok.ibm.com (b01ledav003.gho.pok.ibm.com [9.57.199.108]) by b01cxnp23032.gho.pok.ibm.com (8.14.9/8.14.9/NCO v10.0) with ESMTP id w85DG1iV22872318 (version=TLSv1/SSLv3 cipher=DHE-RSA-AES256-GCM-SHA384 bits=256 verify=FAIL); Wed, 5 Sep 2018 13:16:01 GMT Received: from b01ledav003.gho.pok.ibm.com (unknown [127.0.0.1]) by IMSVA (Postfix) with ESMTP id BE570B205F; Wed, 5 Sep 2018 09:14:48 -0400 (EDT) Received: from b01ledav003.gho.pok.ibm.com (unknown [127.0.0.1]) by IMSVA (Postfix) with ESMTP id A7CD8B2064; Wed, 5 Sep 2018 09:14:48 -0400 (EDT) Received: from sbct-3.pok.ibm.com (unknown [9.47.158.153]) by b01ledav003.gho.pok.ibm.com (Postfix) with ESMTP; Wed, 5 Sep 2018 09:14:48 -0400 (EDT) Subject: Re: [PATCH] tpm: fix response size validation in tpm_get_random() To: Jarkko Sakkinen , linux-integrity@vger.kernel.org Cc: linux-security-module@vger.kernel.org, stable@vger.kernel.org, Peter Huewe , Jason Gunthorpe , Arnd Bergmann , Greg Kroah-Hartman , open list References: <20180903011004.12161-1-jarkko.sakkinen@linux.intel.com> From: Stefan Berger Date: Wed, 5 Sep 2018 09:16:01 -0400 User-Agent: Mozilla/5.0 (X11; Linux x86_64; rv:52.0) Gecko/20100101 Thunderbird/52.8.0 MIME-Version: 1.0 In-Reply-To: <20180903011004.12161-1-jarkko.sakkinen@linux.intel.com> Content-Type: text/plain; charset=utf-8; format=flowed Content-Transfer-Encoding: 7bit Content-Language: en-MW X-TM-AS-GCONF: 00 x-cbid: 18090513-0040-0000-0000-0000046A9A99 X-IBM-SpamModules-Scores: X-IBM-SpamModules-Versions: BY=3.00009676; HX=3.00000242; KW=3.00000007; PH=3.00000004; SC=3.00000266; SDB=6.01083898; UDB=6.00559398; IPR=6.00863899; MB=3.00023125; MTD=3.00000008; XFM=3.00000015; UTC=2018-09-05 13:16:04 X-IBM-AV-DETECTION: SAVI=unused REMOTE=unused XFE=unused x-cbparentid: 18090513-0041-0000-0000-00000871BC15 Message-Id: X-Proofpoint-Virus-Version: vendor=fsecure engine=2.50.10434:,, definitions=2018-09-05_07:,, signatures=0 X-Proofpoint-Spam-Details: rule=outbound_notspam policy=outbound score=0 priorityscore=1501 malwarescore=0 suspectscore=0 phishscore=0 bulkscore=0 spamscore=0 clxscore=1011 lowpriorityscore=0 mlxscore=0 impostorscore=0 mlxlogscore=999 adultscore=0 classifier=spam adjust=0 reason=mlx scancount=1 engine=8.0.1-1807170000 definitions=main-1809050140 Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On 09/02/2018 09:10 PM, Jarkko Sakkinen wrote: > When checking whether the response is large enough to be able to contain > the received random bytes in tpm_get_random() and tpm2_get_random(), > they fail to take account the header size, which should be added to the > minimum size. This commit fixes this issue. > > Cc: stable@vger.kernel.org > Fixes: c659af78eb7b ("tpm: Check size of response before accessing data") > Signed-off-by: Jarkko Sakkinen > --- > drivers/char/tpm/tpm-interface.c | 3 ++- > drivers/char/tpm/tpm2-cmd.c | 4 +++- > 2 files changed, 5 insertions(+), 2 deletions(-) > > diff --git a/drivers/char/tpm/tpm-interface.c b/drivers/char/tpm/tpm-interface.c > index 1a803b0cf980..318a7078b2ba 100644 > --- a/drivers/char/tpm/tpm-interface.c > +++ b/drivers/char/tpm/tpm-interface.c > @@ -1321,7 +1321,8 @@ int tpm_get_random(struct tpm_chip *chip, u8 *out, size_t max) > } > > rlength = be32_to_cpu(tpm_cmd.header.out.length); > - if (rlength < offsetof(struct tpm_getrandom_out, rng_data) + > + if (rlength < TPM_HEADER_SIZE + > + offsetof(struct tpm_getrandom_out, rng_data) + > recd) { > total = -EFAULT; > break; > diff --git a/drivers/char/tpm/tpm2-cmd.c b/drivers/char/tpm/tpm2-cmd.c > index c31b490bd41d..3acf4fd4e5a5 100644 > --- a/drivers/char/tpm/tpm2-cmd.c > +++ b/drivers/char/tpm/tpm2-cmd.c > @@ -329,7 +329,9 @@ int tpm2_get_random(struct tpm_chip *chip, u8 *dest, size_t max) > &buf.data[TPM_HEADER_SIZE]; > recd = min_t(u32, be16_to_cpu(out->size), num_bytes); > if (tpm_buf_length(&buf) < > - offsetof(struct tpm2_get_random_out, buffer) + recd) { > + TPM_HEADER_SIZE + > + offsetof(struct tpm2_get_random_out, buffer) + > + recd) { > err = -EFAULT; > goto out; > } Reviewed-by: Stefan Berger