From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from mx0a-001b2d01.pphosted.com ([148.163.156.1]:35938 "EHLO mx0a-001b2d01.pphosted.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1750733AbeAOVAc (ORCPT ); Mon, 15 Jan 2018 16:00:32 -0500 Received: from pps.filterd (m0098410.ppops.net [127.0.0.1]) by mx0a-001b2d01.pphosted.com (8.16.0.22/8.16.0.22) with SMTP id w0FKwrQO018885 for ; Mon, 15 Jan 2018 16:00:32 -0500 Received: from e06smtp11.uk.ibm.com (e06smtp11.uk.ibm.com [195.75.94.107]) by mx0a-001b2d01.pphosted.com with ESMTP id 2fh0a5rybx-1 (version=TLSv1.2 cipher=AES256-SHA bits=256 verify=NOT) for ; Mon, 15 Jan 2018 16:00:32 -0500 Received: from localhost by e06smtp11.uk.ibm.com with IBM ESMTP SMTP Gateway: Authorized Use Only! Violators will be prosecuted for from ; Mon, 15 Jan 2018 21:00:30 -0000 Subject: Re: [PATCH 0/2] turn on force option for FUSE in builtin policies From: Mimi Zohar To: Christoph Hellwig Cc: Dongsu Park , linux-kernel@vger.kernel.org, Alban Crequy , Miklos Szeredi , Seth Forshee , linux-integrity Date: Mon, 15 Jan 2018 16:00:23 -0500 In-Reply-To: <20180115171825.GA28088@infradead.org> References: <20180115144804.GA28856@infradead.org> <1516033961.6607.18.camel@linux.vnet.ibm.com> <20180115171825.GA28088@infradead.org> Content-Type: text/plain; charset="UTF-8" Mime-Version: 1.0 Message-Id: <1516050023.6607.57.camel@linux.vnet.ibm.com> Sender: linux-integrity-owner@vger.kernel.org List-ID: On Mon, 2018-01-15 at 09:18 -0800, Christoph Hellwig wrote: > On Mon, Jan 15, 2018 at 11:32:41AM -0500, Mimi Zohar wrote: > > For XFS, which considers fsmagic numbers private to the filesystem, > > *always* using the fsmagic number is wrong. As to whether this is > > true for other filesystems is unclear. IMA policies have been defined > > in terms of fsmagic numbers for a long time. fsmagic numbers were > > moved from the filesystems to magic.h for this purpose. Someone would > > have complained earlier if it is always wrong. > > > > I just posted a patch titled "ima: define new policy condition based > > on the filesystem name" to allow policies to be defined in terms of > > the i_sb->s_type->name. > > ima has no business looking at either the name _or_ the magic number. There are a couple of reasons to define policies in terms of the filesystem name or magic numbers. One example is pseudo filesystems (eg. pseudo filesystems - sysfs, securitys, cgroups, selinuxfs, etc). These should never be measured or appraised. The current example is fuse and remote file systems. These should always be re-evaluated and not rely on cached file info. If not based on IMA policy, what do you propose? Define new SB_ flags to indicate IMA disabled/enabled (eg. SB_IMA) and nocaching (eg. SB_IMA_NOCACHE)? Mimi