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=-8.2 required=3.0 tests=HEADER_FROM_DIFFERENT_DOMAINS, INCLUDES_PATCH,MAILING_LIST_MULTI,SIGNED_OFF_BY,SPF_HELO_NONE,SPF_PASS, USER_AGENT_SANE_2 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 B5152C3F68F for ; Thu, 30 Jan 2020 22:26:19 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id 8EC78214AF for ; Thu, 30 Jan 2020 22:26:19 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1726320AbgA3W0S (ORCPT ); Thu, 30 Jan 2020 17:26:18 -0500 Received: from mx0a-001b2d01.pphosted.com ([148.163.156.1]:39828 "EHLO mx0a-001b2d01.pphosted.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1725985AbgA3W0S (ORCPT ); Thu, 30 Jan 2020 17:26:18 -0500 Received: from pps.filterd (m0098410.ppops.net [127.0.0.1]) by mx0a-001b2d01.pphosted.com (8.16.0.42/8.16.0.42) with SMTP id 00UM74nL084971 for ; Thu, 30 Jan 2020 17:26:17 -0500 Received: from e06smtp05.uk.ibm.com (e06smtp05.uk.ibm.com [195.75.94.101]) by mx0a-001b2d01.pphosted.com with ESMTP id 2xv7b4h1ep-1 (version=TLSv1.2 cipher=AES256-GCM-SHA384 bits=256 verify=NOT) for ; Thu, 30 Jan 2020 17:26:17 -0500 Received: from localhost by e06smtp05.uk.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) Thu, 30 Jan 2020 22:26:11 -0000 Received: from d06av21.portsmouth.uk.ibm.com (d06av21.portsmouth.uk.ibm.com [9.149.105.232]) by b06cxnps4074.portsmouth.uk.ibm.com (8.14.9/8.14.9/NCO v10.0) with ESMTP id 00UMQA0l32178278 (version=TLSv1/SSLv3 cipher=DHE-RSA-AES256-GCM-SHA384 bits=256 verify=OK); Thu, 30 Jan 2020 22:26:10 GMT Received: from d06av21.portsmouth.uk.ibm.com (unknown [127.0.0.1]) by IMSVA (Postfix) with ESMTP id BB30B5204E; Thu, 30 Jan 2020 22:26:10 +0000 (GMT) Received: from localhost.localdomain (unknown [9.80.209.158]) by d06av21.portsmouth.uk.ibm.com (Postfix) with ESMTP id E0E3652051; Thu, 30 Jan 2020 22:26:09 +0000 (GMT) Subject: Re: [PATCH 7/8] ima: use ima_hash_algo for collision detection in the measurement list From: Mimi Zohar To: Roberto Sassu , jarkko.sakkinen@linux.intel.com, james.bottomley@hansenpartnership.com, linux-integrity@vger.kernel.org Cc: linux-security-module@vger.kernel.org, linux-kernel@vger.kernel.org, silviu.vlasceanu@huawei.com Date: Thu, 30 Jan 2020 17:26:09 -0500 In-Reply-To: <20200127170443.21538-8-roberto.sassu@huawei.com> References: <20200127170443.21538-1-roberto.sassu@huawei.com> <20200127170443.21538-8-roberto.sassu@huawei.com> Content-Type: text/plain; charset="UTF-8" X-Mailer: Evolution 3.20.5 (3.20.5-1.fc24) Mime-Version: 1.0 Content-Transfer-Encoding: 8bit X-TM-AS-GCONF: 00 x-cbid: 20013022-0020-0000-0000-000003A5A584 X-IBM-AV-DETECTION: SAVI=unused REMOTE=unused XFE=unused x-cbparentid: 20013022-0021-0000-0000-000021FD5D09 Message-Id: <1580423169.6104.18.camel@linux.ibm.com> X-Proofpoint-Virus-Version: vendor=fsecure engine=2.50.10434:6.0.138,18.0.572 definitions=2020-01-30_07:2020-01-30,2020-01-30 signatures=0 X-Proofpoint-Spam-Details: rule=outbound_notspam policy=outbound score=0 suspectscore=0 phishscore=0 adultscore=0 malwarescore=0 clxscore=1015 priorityscore=1501 mlxlogscore=999 bulkscore=0 mlxscore=0 impostorscore=0 lowpriorityscore=0 spamscore=0 classifier=spam adjust=0 reason=mlx scancount=1 engine=8.12.0-1911200001 definitions=main-2001300147 Sender: owner-linux-security-module@vger.kernel.org Precedence: bulk List-ID: On Mon, 2020-01-27 at 18:04 +0100, Roberto Sassu wrote: > Before calculating a digest for each PCR bank, collisions were detected > with a SHA1 digest. This patch includes ima_hash_algo among the algorithms > used to calculate the template digest and checks collisions on that digest. > > Signed-off-by: Roberto Sassu Definitely needed to protect against a sha1 collision attack. > > diff --git a/security/integrity/ima/ima_api.c b/security/integrity/ima/ima_api.c > index ebaf0056735c..a9bb45de6db9 100644 > --- a/security/integrity/ima/ima_api.c > +++ b/security/integrity/ima/ima_api.c > @@ -51,7 +51,7 @@ int ima_alloc_init_template(struct ima_event_data *event_data, > if (!*entry) > return -ENOMEM; > > - (*entry)->digests = kcalloc(ima_tpm_chip->nr_allocated_banks + 1, > + (*entry)->digests = kcalloc(ima_tpm_chip->nr_allocated_banks + 2, > sizeof(*(*entry)->digests), GFP_NOFS); > if (!(*entry)->digests) { > result = -ENOMEM; I would prefer not having to allocate and use "nr_allocated_banks + 1" everywhere, but I understand the need for it.  I'm not sure this patch warrants allocating +2.  Perhaps, if a TPM bank doesn't exist for the IMA default hash algorithm, use a different algorithm or, worst case, continue using the ima_sha1_idx. Mimi