From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from mx0a-001b2d01.pphosted.com ([148.163.156.1]:40882 "EHLO mx0a-001b2d01.pphosted.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1753327AbeDYOvk (ORCPT ); Wed, 25 Apr 2018 10:51:40 -0400 Received: from pps.filterd (m0098393.ppops.net [127.0.0.1]) by mx0a-001b2d01.pphosted.com (8.16.0.22/8.16.0.22) with SMTP id w3PEldvi014967 for ; Wed, 25 Apr 2018 10:51:40 -0400 Received: from e06smtp10.uk.ibm.com (e06smtp10.uk.ibm.com [195.75.94.106]) by mx0a-001b2d01.pphosted.com with ESMTP id 2hju73sv48-1 (version=TLSv1.2 cipher=AES256-GCM-SHA384 bits=256 verify=NOT) for ; Wed, 25 Apr 2018 10:51:40 -0400 Received: from localhost by e06smtp10.uk.ibm.com with IBM ESMTP SMTP Gateway: Authorized Use Only! Violators will be prosecuted for from ; Wed, 25 Apr 2018 15:51:38 +0100 Subject: Re: [PATCH] EVM: Allow runtime modification of the set of verified xattrs From: Mimi Zohar To: Matthew Garrett Cc: linux-integrity , Igor Stoppa Date: Wed, 25 Apr 2018 10:51:32 -0400 In-Reply-To: References: <20180413225220.20130-1-mjg59@google.com> <1523801140.3272.187.camel@linux.vnet.ibm.com> <1523909802.3272.238.camel@linux.vnet.ibm.com> Content-Type: text/plain; charset="UTF-8" Mime-Version: 1.0 Message-Id: <1524667892.3371.67.camel@linux.vnet.ibm.com> Sender: linux-integrity-owner@vger.kernel.org List-ID: [CC'ing Igor] On Tue, 2018-04-24 at 20:03 +0000, Matthew Garrett wrote: > On Mon, Apr 16, 2018 at 1:22 PM Matthew Garrett wrote: > > I could go either way on this - I think that doing it on the command line > > would satisfy all my use cases. > > Thinking about this some more - I think being able to do this at runtime is > actually important. If we add an additional xattr to the signatures then we > want to be able to update machine policy without forcing a reboot first, > otherwise we have a chicken and egg problem where we have to gate any new > package update against having a machine rebooted with an updated command > line (otherwise the signature validation will fail for packages that > contain new signatures) If the list of xattr names is append only, there is no reason for re- allocating the entire xattr name list each time. As long as the xattr name list pointer is defined as __ro_after_init, we can work with Igor on using "protectable memory" once it is upstreamed. Mimi