All of lore.kernel.org
 help / color / mirror / Atom feed
From: Norman Elton <normelton@gmail.com>
To: linux-nfs@vger.kernel.org
Subject: Excessive group membership causes permission denied
Date: Mon, 18 Mar 2013 14:46:48 -0400	[thread overview]
Message-ID: <CAPCnwUeMeQuZo1ygbXAB-KXJbv71wtTsTbaELcT=ombWVSG4mg@mail.gmail.com> (raw)

There is a fairly well documented bug that we've run against. When
using Active Directory as a KDC, users with a large number of group
memberships can overrun a UDP packet, causing Kerberos to fall back to
TCP. When a user logs into the system, they have a kerberos ticket,
but get a "permission denied" when accessing the NFS share. We've
reproduced this by taking a functioning user, adding tons of group
membership. The error message pops right up.

The traditional fix is to set NO_AUTH_DATA_REQUIRED on the NFS
server's machine account, as explained here:
http://theether.net/kb/100205.

While this seems to work, it's a bit of a dirty hack. Any thoughts on
a root-cause? We're happy to serve as a guinea pig if anyone can point
us in the right direction.

Thanks,

Norman

                 reply	other threads:[~2013-03-18 18:46 UTC|newest]

Thread overview: [no followups] expand[flat|nested]  mbox.gz  Atom feed

Reply instructions:

You may reply publicly to this message via plain-text email
using any one of the following methods:

* Save the following mbox file, import it into your mail client,
  and reply-to-all from there: mbox

  Avoid top-posting and favor interleaved quoting:
  https://en.wikipedia.org/wiki/Posting_style#Interleaved_style

* Reply using the --to, --cc, and --in-reply-to
  switches of git-send-email(1):

  git send-email \
    --in-reply-to='CAPCnwUeMeQuZo1ygbXAB-KXJbv71wtTsTbaELcT=ombWVSG4mg@mail.gmail.com' \
    --to=normelton@gmail.com \
    --cc=linux-nfs@vger.kernel.org \
    /path/to/YOUR_REPLY

  https://kernel.org/pub/software/scm/git/docs/git-send-email.html

* If your mail client supports setting the In-Reply-To header
  via mailto: links, try the mailto: link
Be sure your reply has a Subject: header at the top and a blank line before the message body. 
This is an external index of several public inboxes,
see mirroring instructions on how to clone and mirror
all data and code used by this external index.