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=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 9A3DDC10F01 for ; Wed, 20 Feb 2019 12:26:54 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id 7593C2147C for ; Wed, 20 Feb 2019 12:26:54 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1726414AbfBTM0x (ORCPT ); Wed, 20 Feb 2019 07:26:53 -0500 Received: from mx0b-001b2d01.pphosted.com ([148.163.158.5]:48582 "EHLO mx0a-001b2d01.pphosted.com" rhost-flags-OK-OK-OK-FAIL) by vger.kernel.org with ESMTP id S1727409AbfBTM0x (ORCPT ); Wed, 20 Feb 2019 07:26:53 -0500 Received: from pps.filterd (m0098419.ppops.net [127.0.0.1]) by mx0b-001b2d01.pphosted.com (8.16.0.27/8.16.0.27) with SMTP id x1KCOjEt042507 for ; Wed, 20 Feb 2019 07:26:52 -0500 Received: from e06smtp05.uk.ibm.com (e06smtp05.uk.ibm.com [195.75.94.101]) by mx0b-001b2d01.pphosted.com with ESMTP id 2qs6eus8pe-1 (version=TLSv1.2 cipher=AES256-GCM-SHA384 bits=256 verify=NOT) for ; Wed, 20 Feb 2019 07:26:51 -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) Wed, 20 Feb 2019 12:26:48 -0000 Received: from d06av21.portsmouth.uk.ibm.com (d06av21.portsmouth.uk.ibm.com [9.149.105.232]) by b06cxnps4076.portsmouth.uk.ibm.com (8.14.9/8.14.9/NCO v10.0) with ESMTP id x1KCQloU26869944 (version=TLSv1/SSLv3 cipher=DHE-RSA-AES256-GCM-SHA384 bits=256 verify=OK); Wed, 20 Feb 2019 12:26:48 GMT Received: from d06av21.portsmouth.uk.ibm.com (unknown [127.0.0.1]) by IMSVA (Postfix) with ESMTP id D284352050; Wed, 20 Feb 2019 12:26:47 +0000 (GMT) Received: from localhost.localdomain (unknown [9.80.107.132]) by d06av21.portsmouth.uk.ibm.com (Postfix) with ESMTP id 508A752052; Wed, 20 Feb 2019 12:26:47 +0000 (GMT) Subject: Re: [PATCH RFC 0/4] IMA on NFS prototype From: Mimi Zohar To: Chuck Lever Cc: linux-nfs@vger.kernel.org, linux-integrity@vger.kernel.org Date: Wed, 20 Feb 2019 07:26:36 -0500 In-Reply-To: References: <20190214203336.6469.34750.stgit@manet.1015granger.net> <1550623002.17768.10.camel@linux.ibm.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: 19022012-0020-0000-0000-000003190B2C X-IBM-AV-DETECTION: SAVI=unused REMOTE=unused XFE=unused x-cbparentid: 19022012-0021-0000-0000-0000216A5669 Message-Id: <1550665596.17768.32.camel@linux.ibm.com> X-Proofpoint-Virus-Version: vendor=fsecure engine=2.50.10434:,, definitions=2019-02-20_11:,, 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=1015 lowpriorityscore=0 mlxscore=0 impostorscore=0 mlxlogscore=999 adultscore=0 classifier=spam adjust=0 reason=mlx scancount=1 engine=8.0.1-1810050000 definitions=main-1902200090 Sender: linux-nfs-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-nfs@vger.kernel.org On Tue, 2019-02-19 at 22:51 -0500, Chuck Lever wrote: > > On Feb 19, 2019, at 7:36 PM, Mimi Zohar wrote: > > > > Hi Chuck, > > > >> EVM is not supported in this prototype. NFS does not support several > >> of the xattrs that are protected by EVM: SMACK64, Posix ACLs, and > >> Linux file capabilities are not supported, which makes EVM more > >> difficult to support on NFS mounts. > > > > There's no requirement for all of these xattrs to exist. If an xattr > > does exist, then it is included in the security.evm hmac/signature. > > Understood. The issue is that if they exist on a file residing on an NFS server, > such xattrs would not be visible to clients. My understanding is that then EVM > verification would fail on such files on NFS clients. > > We could possibly make EVM work in limited scenarios until such time that > the NFS protocol can make those xattrs available to NFS clients. I hope that > having only security.ima is useful at least for experimenting and maybe more. > > However, if folks think having security.evm also is needed, that is straight- > forward... just saying that there are currently other limits in NFS that make a > full EVM implementation problematic. Thank you for the explanation.  Yes, I think there is a benefit of having a file signature, without EVM. Mimi