From: "J. Bruce Fields" <bfields@fieldses.org>
To: David Quigley <dpquigl@davequigley.com>
Cc: Casey Schaufler <casey@schaufler-ca.com>,
trond.myklebust@netapp.com, sds@tycho.nsa.gov,
linux-nfs@vger.kernel.org, selinux@tycho.nsa.gov,
linux-security-module@vger.kernel.org
Subject: Re: Labeled NFS [v5]
Date: Fri, 30 Nov 2012 07:14:37 -0500 [thread overview]
Message-ID: <20121130121437.GC614@fieldses.org> (raw)
In-Reply-To: <3ea3f70e0a5cdb99f1594019b7bd619d@countercultured.net>
On Thu, Nov 29, 2012 at 09:02:49PM -0500, David Quigley wrote:
> On 11/29/2012 20:50, Casey Schaufler wrote:
> >On 11/29/2012 4:46 PM, David Quigley wrote:
> >>On 11/29/2012 19:34, Casey Schaufler wrote:
> >>>I would think that were it not for the case that access is denied
> >>>and I get an audit record for nfsd that reports a subject
> >>>label of "_"
> >>>(which is correct for nfsd but not the process attempting
> >>>access) and
> >>>an object label of "WhooHoo", which is correct. The server side
> >>>looks like it might be working right, given the information that it
> >>>has.
> >>>
> >>
> >>Ok so this is the problem. nfsd is a kernel thread I believe. In
> >>SELinux land it has the type kernel_t which is all powerful. We
> >>don't
> >>have client label transport yet (That requires RPCSECGSSv3). Is
> >>there
> >>a way you can have that kernel thread running as a type that has
> >>access to everything?
> >
> >That would be having CAP_MAC_ADMIN and CAP_MAC_OVERRIDE in Smackese.
> >Looking at /proc/<pid-of-nfsd>/status we see CapEff of fff...fff
> >which
> >is to say, all capabilities.
> >
>
> Hmm thats interesting then. You could try using rpcdebug -m nfsd to
> turn on some of the debugging to look around the internals and
> figure out whats going on. If you pass -v it will give you all of
> the potential flags.
>
> >
> >>I think that is the current problem. Which makes perfect sense. If
> >>your kernel threads don't get started with max privilege then the
> >>server would be denied access on all of the file attributes and
> >>wouldn't be able to ship it over the wire properly.
> >
> >OK. I haven't had to do anything with kernel threads so far.
> >Where is NFS setting these up? Poking around fs/nfsd looks like
> >the place, but I haven't seen anything there that makes it look
> >like they would be running without capabilities. Clearly, that's
> >what I'm seeing. It looks as if the credential of nfsd does not
> >match what /proc reports. Bother.
> >
>
> I'm not entirely sure whats up either. If you want to look for the
> NFSd threads they are in fs/nfsd/nfssvc.c. The main function starts
> on line 487.
I'm not following the discussion, but: maybe you want to look at
fs/nfsd/auth.c:nfsd_setuser() ? In particular, the
cap_{drop/raise}_nfsd_set() calls at the end.
--b.
next prev parent reply other threads:[~2012-11-30 12:14 UTC|newest]
Thread overview: 88+ messages / expand[flat|nested] mbox.gz Atom feed top
2012-11-12 6:15 Labeled NFS [v5] David Quigley
2012-11-12 6:15 ` [PATCH 01/13] Security: Add hook to calculate context based on a negative dentry David Quigley
2012-11-12 12:13 ` J. Bruce Fields
2012-11-12 14:52 ` Dave Quigley
2012-11-12 6:15 ` [PATCH 02/13] Security: Add Hook to test if the particular xattr is part of a MAC model David Quigley
2012-11-12 12:15 ` J. Bruce Fields
2012-11-12 14:56 ` Dave Quigley
2012-11-12 16:36 ` J. Bruce Fields
2012-11-12 19:36 ` David P. Quigley
2012-11-12 21:43 ` J. Bruce Fields
2012-11-13 0:12 ` Dave Quigley
2012-11-12 6:15 ` [PATCH 03/13] LSM: Add flags field to security_sb_set_mnt_opts for in kernel mount data David Quigley
2012-11-12 6:15 ` [PATCH 04/13] SELinux: Add new labeling type native labels David Quigley
2012-11-12 6:15 ` [PATCH 05/13] KConfig: Add KConfig entries for Labeled NFS David Quigley
2012-11-12 14:45 ` J. Bruce Fields
2012-11-12 14:57 ` Dave Quigley
2012-11-12 6:15 ` [PATCH 06/13] NFSv4: Add label recommended attribute and NFSv4 flags David Quigley
2012-11-12 6:15 ` [PATCH 07/13] NFSv4: Introduce new label structure David Quigley
2012-11-12 15:13 ` J. Bruce Fields
2012-11-12 15:32 ` David P. Quigley
2012-11-12 16:05 ` J. Bruce Fields
2012-11-12 16:53 ` David P. Quigley
2012-11-12 17:50 ` J. Bruce Fields
2012-11-12 6:15 ` [PATCH 08/13] NFSv4: Extend fattr bitmaps to support all 3 words David Quigley
2012-11-12 6:15 ` [PATCH 09/13] NFS:Add labels to client function prototypes David Quigley
2012-11-12 6:15 ` [PATCH 10/13] NFS: Add label lifecycle management David Quigley
2012-11-12 15:33 ` J. Bruce Fields
2012-11-12 15:36 ` David P. Quigley
2012-11-12 6:15 ` [PATCH 11/13] NFS: Client implementation of Labeled-NFS David Quigley
2012-11-12 6:15 ` [PATCH 12/13] NFS: Extend NFS xattr handlers to accept the security namespace David Quigley
2012-11-12 6:15 ` [PATCH 13/13] NFSD: Server implementation of MAC Labeling David Quigley
2012-11-12 16:31 ` J. Bruce Fields
2012-11-12 15:23 ` Labeled NFS [v5] J. Bruce Fields
2012-11-12 15:34 ` David P. Quigley
2012-11-12 16:09 ` J. Bruce Fields
2012-11-12 20:56 ` Steve Dickson
2012-11-13 1:39 ` Dave Quigley
2012-11-13 12:55 ` Steve Dickson
2012-11-14 4:32 ` Dave Quigley
2012-11-14 13:45 ` J. Bruce Fields
2012-11-14 13:50 ` David Quigley
2012-11-14 13:59 ` J. Bruce Fields
2012-11-14 14:01 ` David Quigley
2012-11-14 14:04 ` David Quigley
2012-11-14 14:24 ` J. Bruce Fields
2012-11-14 14:30 ` David Quigley
2012-11-15 16:00 ` Casey Schaufler
2012-11-15 20:28 ` David Quigley
2012-11-16 3:34 ` Casey Schaufler
2012-11-16 3:43 ` David Quigley
2012-11-16 4:58 ` Dave Quigley
2012-11-16 4:59 ` Dave Quigley
2012-11-14 13:56 ` David Quigley
2012-11-12 16:33 ` J. Bruce Fields
2012-11-12 20:44 ` Dave Quigley
2012-11-12 22:23 ` Casey Schaufler
2012-11-13 3:16 ` Dave Quigley
2012-11-20 21:09 ` Casey Schaufler
2012-11-21 0:04 ` Dave Quigley
2012-11-21 0:29 ` Dave Quigley
2012-11-21 0:32 ` Casey Schaufler
2012-11-21 0:37 ` Dave Quigley
2012-11-21 2:52 ` Casey Schaufler
2012-11-21 3:28 ` Dave Quigley
2012-11-28 18:57 ` Casey Schaufler
2012-11-29 1:14 ` Dave Quigley
2012-11-29 2:08 ` Casey Schaufler
2012-11-29 22:28 ` Casey Schaufler
2012-11-29 22:49 ` David Quigley
2012-11-30 0:02 ` David Quigley
2012-11-30 0:07 ` David Quigley
2012-11-30 0:34 ` Casey Schaufler
2012-11-30 0:46 ` David Quigley
2012-11-30 1:50 ` Casey Schaufler
2012-11-30 2:02 ` David Quigley
2012-11-30 12:14 ` J. Bruce Fields [this message]
2012-11-30 12:57 ` David Quigley
2012-11-30 13:17 ` David Quigley
2012-11-30 13:28 ` Stephen Smalley
2012-11-30 13:35 ` David Quigley
2012-11-30 13:50 ` Stephen Smalley
2012-11-30 14:02 ` David Quigley
2012-11-30 16:21 ` Casey Schaufler
2012-11-30 16:28 ` David Quigley
2012-12-03 18:27 ` Casey Schaufler
2012-11-30 16:55 ` J. Bruce Fields
2012-11-30 16:59 ` David Quigley
2012-11-30 13:20 ` David Quigley
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