From mboxrd@z Thu Jan 1 00:00:00 1970 From: Casey Schaufler Subject: Re: [PATCH 01/11] Security: Add hook to get full maclabel xattr name Date: Fri, 29 Feb 2008 09:52:15 -0800 (PST) Message-ID: <880770.6811.qm@web36613.mail.mud.yahoo.com> References: <1204291865.31790.235.camel@moss-spartans.epoch.ncsc.mil> Reply-To: casey@schaufler-ca.com Mime-Version: 1.0 Content-Type: text/plain; charset=US-ASCII Content-Transfer-Encoding: 7BIT Cc: casey@schaufler-ca.com, Dave Quigley , viro@ftp.linux.org.uk, trond.myklebust@fys.uio.no, bfields@fieldses.org, linux-kernel@vger.kernel.org, linux-fsdevel@vger.kernel.org, LSM List To: Stephen Smalley , Christoph Hellwig Return-path: In-Reply-To: <1204291865.31790.235.camel@moss-spartans.epoch.ncsc.mil> Sender: linux-kernel-owner@vger.kernel.org List-Id: linux-fsdevel.vger.kernel.org --- Stephen Smalley wrote: > > On Thu, 2008-02-28 at 18:48 -0500, Christoph Hellwig wrote: > > On Thu, Feb 28, 2008 at 02:30:35PM -0500, Stephen Smalley wrote: > > > This is an interface to be used by NFS to get information from the > > > security module. The information desired is specific to the MAC > > > labeling functionality in NFSv4 that is being proposed. That > > > functionality is MAC specific (necessarily so, just like the ACL > > > functionality is ACL specific). We are hiding the SELinux-specific bits > > > behind the LSM interface, and non-MAC LSMs are free to return NULL in > > > order to indicate that they don't support MAC labeling. We do NOT want > > > the capability module to return its security blob here, or any other > > > non-MAC LSM - it will yield the wrong semantics for the NFS MAC support. > > > > I think Casey is totally right here. The LSM interface should not be > > as specific here. If you want to limit the NFSv4 interface to single > > MAC xattr label based systems add an additional method to check if > > the LSM is that. But the proper fix is of course to not add somthing > > so specific to NFSv4 at all, as it's got enough shortcoming already. > > Please add a proper xattr protocol. It's not like it's hard, SGI > > has been doing this in IRIX for NFSv3 for ages as a sideband protocol, > > and even release the reference source under the GPL. Just either use > > that with NFSv4 or if you feel fancy merge it into the NFS spec for > > NFSv6^H4.2. > > > > > In any event, I don't think we need your permission. > > > > Wow, that's rude even to someone as direct as me. Casey is the only > > other person having an in-tree LSM, and I think his input in this > > area is important. But if not I as a VFS person can happily give > > you my "no" for the current version from the VFS point of view. > > Fair point - my apologies to Casey. Accepted. Now we work together like horses in troika. Casey Schaufler casey@schaufler-ca.com