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 Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by smtp.lore.kernel.org (Postfix) with ESMTP id 95606C433F5 for ; Fri, 18 Mar 2022 20:55:11 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S238313AbiCRU43 (ORCPT ); Fri, 18 Mar 2022 16:56:29 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:51738 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S234633AbiCRU42 (ORCPT ); Fri, 18 Mar 2022 16:56:28 -0400 Received: from mx0a-001b2d01.pphosted.com (mx0b-001b2d01.pphosted.com [148.163.158.5]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 42B701AA072; Fri, 18 Mar 2022 13:55:09 -0700 (PDT) Received: from pps.filterd (m0098413.ppops.net [127.0.0.1]) by mx0b-001b2d01.pphosted.com (8.16.1.2/8.16.1.2) with SMTP id 22IIXEZF013069; Fri, 18 Mar 2022 20:55:06 GMT DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=ibm.com; h=message-id : date : mime-version : subject : to : cc : references : from : in-reply-to : content-type : content-transfer-encoding; s=pp1; bh=MgE2OTdMl1fgmgWIKOGl9q1PJ75sFNoa+qwLQ8o4xYg=; b=COwbQdjX/MXHjLKg7Jtz9ssJGGjEREMGQixWNZN5AWEDYYo5AQPdoz2r48tYi4QMNmNf MaOK/sKbJhPV01X3vCqeT+7wSPQ6MxX58Fdn98conkKrMomPP9mQqKbFDpY40kaljpAU RF+/8fYhP5G+Lda+ytBZHzl4U+5kxv+/wCX16dVkijA3r6+dtsekY3EFOrnnvoZbbx2x V2YtNuLSlGq3PClrRsqbuEB40ghC1lR2Wf+ZPhBrfseVecI+NH9ESJXLyvZlOLw9LHSk 5TYZnSX5aj/odh7gHgn+K6eGZz7V+RsSI3DtEJ+pbp5H3hyBCMk1qS5v5HNaE7u8GFfa 7w== Received: from ppma02dal.us.ibm.com (a.bd.3ea9.ip4.static.sl-reverse.com [169.62.189.10]) by mx0b-001b2d01.pphosted.com with ESMTP id 3evj92s654-1 (version=TLSv1.2 cipher=ECDHE-RSA-AES256-GCM-SHA384 bits=256 verify=NOT); Fri, 18 Mar 2022 20:55:05 +0000 Received: from pps.filterd (ppma02dal.us.ibm.com [127.0.0.1]) by ppma02dal.us.ibm.com (8.16.1.2/8.16.1.2) with SMTP id 22IKs2Yn032013; Fri, 18 Mar 2022 20:55:05 GMT Received: from b03cxnp07029.gho.boulder.ibm.com (b03cxnp07029.gho.boulder.ibm.com [9.17.130.16]) by ppma02dal.us.ibm.com with ESMTP id 3etaj7m0en-1 (version=TLSv1.2 cipher=ECDHE-RSA-AES256-GCM-SHA384 bits=256 verify=NOT); Fri, 18 Mar 2022 20:55:05 +0000 Received: from b03ledav001.gho.boulder.ibm.com (b03ledav001.gho.boulder.ibm.com [9.17.130.232]) by b03cxnp07029.gho.boulder.ibm.com (8.14.9/8.14.9/NCO v10.0) with ESMTP id 22IKt3Wa28049790 (version=TLSv1/SSLv3 cipher=DHE-RSA-AES256-GCM-SHA384 bits=256 verify=OK); Fri, 18 Mar 2022 20:55:03 GMT Received: from b03ledav001.gho.boulder.ibm.com (unknown [127.0.0.1]) by IMSVA (Postfix) with ESMTP id 605706E056; Fri, 18 Mar 2022 20:55:03 +0000 (GMT) Received: from b03ledav001.gho.boulder.ibm.com (unknown [127.0.0.1]) by IMSVA (Postfix) with ESMTP id 5F4406E05B; Fri, 18 Mar 2022 20:55:02 +0000 (GMT) Received: from [9.47.158.152] (unknown [9.47.158.152]) by b03ledav001.gho.boulder.ibm.com (Postfix) with ESMTP; Fri, 18 Mar 2022 20:55:02 +0000 (GMT) Message-ID: Date: Fri, 18 Mar 2022 16:55:01 -0400 MIME-Version: 1.0 User-Agent: Mozilla/5.0 (X11; Linux x86_64; rv:91.0) Gecko/20100101 Thunderbird/91.6.2 Subject: Re: [PATCH v6 5/5] fsverity: update the documentation Content-Language: en-US To: Mimi Zohar , linux-integrity@vger.kernel.org Cc: Eric Biggers , linux-fscrypt@vger.kernel.org, linux-kernel@vger.kernel.org References: <20220318182151.100847-1-zohar@linux.ibm.com> <20220318182151.100847-6-zohar@linux.ibm.com> From: Stefan Berger In-Reply-To: <20220318182151.100847-6-zohar@linux.ibm.com> Content-Type: text/plain; charset=UTF-8; format=flowed Content-Transfer-Encoding: 7bit X-TM-AS-GCONF: 00 X-Proofpoint-GUID: 7fuyGot6UiJEYAiTITeCkQjRXJT6VpAb X-Proofpoint-ORIG-GUID: 7fuyGot6UiJEYAiTITeCkQjRXJT6VpAb X-Proofpoint-Virus-Version: vendor=baseguard engine=ICAP:2.0.205,Aquarius:18.0.850,Hydra:6.0.425,FMLib:17.11.64.514 definitions=2022-03-18_14,2022-03-15_01,2022-02-23_01 X-Proofpoint-Spam-Details: rule=outbound_notspam policy=outbound score=0 spamscore=0 lowpriorityscore=0 suspectscore=0 bulkscore=0 clxscore=1011 phishscore=0 mlxlogscore=999 impostorscore=0 mlxscore=0 priorityscore=1501 adultscore=0 malwarescore=0 classifier=spam adjust=0 reason=mlx scancount=1 engine=8.12.0-2202240000 definitions=main-2203180109 Precedence: bulk List-ID: X-Mailing-List: linux-fscrypt@vger.kernel.org On 3/18/22 14:21, Mimi Zohar wrote: > Update the fsverity documentation related to IMA signature support. > > Signed-off-by: Mimi Zohar > --- > Documentation/filesystems/fsverity.rst | 22 +++++++++++++--------- > 1 file changed, 13 insertions(+), 9 deletions(-) > > diff --git a/Documentation/filesystems/fsverity.rst b/Documentation/filesystems/fsverity.rst > index 1d831e3cbcb3..28a47488848e 100644 > --- a/Documentation/filesystems/fsverity.rst > +++ b/Documentation/filesystems/fsverity.rst > @@ -74,8 +74,12 @@ authenticating the files is up to userspace. However, to meet some > users' needs, fs-verity optionally supports a simple signature > verification mechanism where users can configure the kernel to require > that all fs-verity files be signed by a key loaded into a keyring; see > -`Built-in signature verification`_. Support for fs-verity file hashes > -in IMA (Integrity Measurement Architecture) policies is also planned. > +`Built-in signature verification`_. > + > +IMA supports including fs-verity file digests and signatures in the > +IMA (Integrity Measurement Architecture) measurement list and The Integrity Measurement Architecture (IMA) supports including ... > +verifying fs-verity based file signatures stored as security.ima > +xattrs, based on policy. > > User API > ======== > @@ -653,13 +657,13 @@ weren't already directly answered in other parts of this document. > hashed and what to do with those hashes, such as log them, > authenticate them, or add them to a measurement list. > > - IMA is planned to support the fs-verity hashing mechanism as an > - alternative to doing full file hashes, for people who want the > - performance and security benefits of the Merkle tree based hash. > - But it doesn't make sense to force all uses of fs-verity to be > - through IMA. As a standalone filesystem feature, fs-verity > - already meets many users' needs, and it's testable like other > - filesystem features e.g. with xfstests. > + IMA supports the fs-verity hashing mechanism as an alternative > + to doing full file hashes, for people who want the performance IMA supports the fs-verity hashing mechanism as an alternative to full file hashes for those who want the performance and security benefits ... > + and security benefits of the Merkle tree based hash. But it > + doesn't make sense to force all uses of fs-verity to be through However, it doesn't make sense ... > + IMA. As a standalone filesystem feature, fs-verity already meets > + many users' needs, and it's testable like other filesystem > + features e.g. with xfstests. Fs-verity already meets many user' needs even as a standalone filesystem feature and it is testable like other ... > > :Q: Isn't fs-verity useless because the attacker can just modify the > hashes in the Merkle tree, which is stored on-disk?