From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1760577Ab0JZWJ7 (ORCPT ); Tue, 26 Oct 2010 18:09:59 -0400 Received: from terminus.zytor.com ([198.137.202.10]:43425 "EHLO mail.zytor.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1760338Ab0JZWJ5 (ORCPT ); Tue, 26 Oct 2010 18:09:57 -0400 Message-ID: <4CC75155.4060807@zytor.com> Date: Tue, 26 Oct 2010 15:08:21 -0700 From: "H. Peter Anvin" User-Agent: Mozilla/5.0 (X11; U; Linux x86_64; en-US; rv:1.9.2.9) Gecko/20100921 Fedora/3.1.4-1.fc13 Thunderbird/3.1.4 MIME-Version: 1.0 To: John Stoffel CC: Eric Paris , linux-kernel@vger.kernel.org, linux-security-module@vger.kernel.org, linux-fsdevel@vger.kernel.org, hch@infradead.org, zohar@us.ibm.com, warthog9@kernel.org, david@fromorbit.com, jmorris@namei.org, kyle@mcmartin.ca, akpm@linux-foundation.org, torvalds@linux-foundation.org, mingo@elte.hu, viro@zeniv.linux.org.uk Subject: Re: [PATCH 06/11] IMA: use i_writecount rather than a private counter References: <20101025184118.20504.24290.stgit@paris.rdu.redhat.com> <20101025184152.20504.94048.stgit@paris.rdu.redhat.com> <19653.55831.692904.538148@quad.stoffel.home> <1288043557.2655.34.camel@localhost.localdomain> <19654.56681.488563.135215@quad.stoffel.home> In-Reply-To: <19654.56681.488563.135215@quad.stoffel.home> Content-Type: text/plain; charset=ISO-8859-1 Content-Transfer-Encoding: 7bit Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On 10/26/2010 06:53 AM, John Stoffel wrote: > > No. What I was trying to get at, and probably poorly, was the comment > you made about having to keep the IMA data structures around, even if > IMA has been disabled, so that you could continue to claim integrity > if IMA was re-enabled. > > So my question is really about the following situation: > > 1. System boots up, IMA is enabled. > 2. SysAdmin notices and turns it off. > - does the IMA overhead (not the per-inode 4 bytes) go away? > - do the various in memory data structures get freed? > - does the pointer in the inode get null'ed? > I think it's reasonable to require a reboot in this case. -hpa