From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1753350AbeBERb4 (ORCPT ); Mon, 5 Feb 2018 12:31:56 -0500 Received: from mx0b-001b2d01.pphosted.com ([148.163.158.5]:34568 "EHLO mx0a-001b2d01.pphosted.com" rhost-flags-OK-OK-OK-FAIL) by vger.kernel.org with ESMTP id S1753277AbeBERbt (ORCPT ); Mon, 5 Feb 2018 12:31:49 -0500 Subject: Re: [PATCH] ima: define new policy condition based on the filesystem name From: Mimi Zohar To: Christoph Hellwig Cc: linux-integrity , linux-security-module , linux-fsdevel , linux-kernel , TarasKondratiuk , Victor Kamensky , RobLandley Date: Mon, 05 Feb 2018 12:31:41 -0500 In-Reply-To: <20180115171914.GB28088@infradead.org> References: <1516033236.6607.6.camel@linux.vnet.ibm.com> <20180115162726.GB15686@infradead.org> <1516034407.6607.26.camel@linux.vnet.ibm.com> <20180115171914.GB28088@infradead.org> 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: 18020517-0008-0000-0000-000004C9A272 X-IBM-AV-DETECTION: SAVI=unused REMOTE=unused XFE=unused x-cbparentid: 18020517-0009-0000-0000-00001E5D4C3D Message-Id: <1517851901.3736.120.camel@linux.vnet.ibm.com> X-Proofpoint-Virus-Version: vendor=fsecure engine=2.50.10432:,, definitions=2018-02-05_04:,, 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 impostorscore=0 adultscore=0 classifier=spam adjust=0 reason=mlx scancount=1 engine=8.0.1-1709140000 definitions=main-1802050220 Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Mon, 2018-01-15 at 09:19 -0800, Christoph Hellwig wrote: > On Mon, Jan 15, 2018 at 11:40:07AM -0500, Mimi Zohar wrote: > > rootfs IS different than other filesystems, as other filesystems > > uniquely identify the underlying filesystem type.  rootfs can be a > > ramfs or tmpfs filesystem.  Only tmpfs supports xattrs. > > Tons of filesystems only have xattrs optionally. Check for goddamn > xattrs if that is the requirement and not a name that has absolutely > zero meaning for functionality. That is the whole point! I should have said the main reason for defining a rootfs policy rule is not to differentiate it from ramfs, but the ability to require file signatures. Up to now, CPIO did not support xattrs.  With Taras' proposed CPIO xattr patch set, the initramfs can now be properly labeled with file signatures.  Since only some systems will include file signatures in the initramfs, we need to be able to differentiate between those that require file signatures from those that don't. Mimi