Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1756197AbYLaJrm (ORCPT ); Wed, 31 Dec 2008 04:47:42 -0500 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S1755147AbYLaJr3 (ORCPT ); Wed, 31 Dec 2008 04:47:29 -0500 Received: from casper.infradead.org ([85.118.1.10]:33213 "EHLO casper.infradead.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1753812AbYLaJr2 (ORCPT ); Wed, 31 Dec 2008 04:47:28 -0500 Date: Wed, 31 Dec 2008 10:49:04 +0100 From: Arjan van de Ven To: "Muntz, Daniel" Cc: "Trond Myklebust" , "Andrew Morton" , "Stephen Rothwell" , "Bernd Schubert" , , , , , , , Subject: Re: Pull request for FS-Cache, including NFS patches Message-ID: <20081231104904.5a89fc60@infradead.org> In-Reply-To: <7A24DF798E223B4C9864E8F92E8C93EC01AAFE66@SACMVEXC1-PRD.hq.netapp.com> References: <1230662677.4952.37.camel@heimdal.trondhjem.org> <7A24DF798E223B4C9864E8F92E8C93EC01AAFE66@SACMVEXC1-PRD.hq.netapp.com> Organization: Intel X-Mailer: Claws Mail 3.6.0 (GTK+ 2.14.5; i386-redhat-linux-gnu) Mime-Version: 1.0 Content-Type: text/plain; charset=US-ASCII Content-Transfer-Encoding: 7bit X-SRS-Rewrite: SMTP reverse-path rewritten from by casper.infradead.org See http://www.infradead.org/rpr.html Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 1396 Lines: 38 On Tue, 30 Dec 2008 14:15:42 -0800 "Muntz, Daniel" wrote: > >> As for security, look at what MIT had to do to prevent local disk > >> caching from breaking the security guarantees of AFS. > > > >See what David has added to the LSM code to provide the same > >guarantees > for cachefs... > > > >Trond > > Unless it (at least) leverages TPM, the issues I had in mind can't > really be addressed in code. One requirement is to prevent a local > root user from accessing fs information without appropriate > permissions. we're talking about NFS here (but also local CDs and potentially CIFS etc). The level of security you're talking about is going to be the same before or after cachefs.... very little against local root. Frankly, any networking filesystem just trusts that the connection is authenticated... eg there is SOMEONE on the machine who has the right credentials. Cachefs doesn't change that; it still validates with the server before giving userspace the data. -- Arjan van de Ven Intel Open Source Technology Centre For development, discussion and tips for power savings, visit http://www.lesswatts.org -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/