From: "J. Bruce Fields" <bfields@fieldses.org>
To: Benjamin Coddington <bcodding@uvm.edu>
Cc: linux-nfs@vger.kernel.org
Subject: Re: multiple service identities for svcgssd
Date: Wed, 20 Jul 2011 09:41:00 -0400 [thread overview]
Message-ID: <20110720134100.GA26614@fieldses.org> (raw)
In-Reply-To: <960320AD-849D-45D7-B61F-859CDD957375@uvm.edu>
On Wed, Jul 20, 2011 at 08:56:47AM -0400, Benjamin Coddington wrote:
> On Jul 13, 2011, at 1:35 PM, J. Bruce Fields wrote:
> > On Wed, Jul 13, 2011 at 12:03:03PM -0400, Benjamin Coddington wrote:
> >> I am working on a linux NFS cluster that requires a single svcgssd to establish contexts under multiple service names.
> >>
> >> In this scenario, svcgssd can be called with "-n" so that it acquires creds at context creation. After running this way I found svcgssd opens a file to the kerberos replay cache for every context/cred, eventually reaching ulimit. For a busy cluster with many different client-user pairs that becomes a problem. I am lost in the gss_krb5 code, but suspect that the kerberos code leaks credentials in this configuration.
> >>
> >> Ondrej Palkovsky submitted a patch to specify multiple identities and acquire creds up-front using multiples of "-h": http://marc.info/?l=linux-nfsv4&m=123685185324902&w=2
> >>
> >> I've updated that work to be current to nfs-utils-1.2.3 which solves our immediate problem, and it works well -- but running svcgssd with '-n' is still going to leak file handles to the replay cache. What's the best way to fix this? Can the created-on-the-fly cred can be re-used for subsequent contexts?
> >
> > Sounds like a likely kerberos bug as well--may be use asking the
> > kerberos folks?
> >
> > --b.
>
> It is a kerberos bug where the context is not cleaned up in gss_export_lucid_sec_context(), so svcgssd leaks a bit. Here's a reference to the kerberos problem: http://marc.info/?t=131068390400045&r=1&w=2
Good, thanks for following up.
--b.
prev parent reply other threads:[~2011-07-20 13:41 UTC|newest]
Thread overview: 5+ messages / expand[flat|nested] mbox.gz Atom feed top
2011-07-13 16:03 multiple service identities for svcgssd Benjamin Coddington
2011-07-13 17:10 ` Steve Dickson
2011-07-13 17:35 ` J. Bruce Fields
2011-07-20 12:56 ` Benjamin Coddington
2011-07-20 13:41 ` J. Bruce Fields [this message]
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