Received-SPF: pass (google.com: domain of linux-nfs-owner@vger.kernel.org designates 2620:137:e000::1:20 as permitted sender) client-ip=2620:137:e000::1:20;
MIME-Version: 1.0
Date:   Mon, 06 Jun 2022 18:14:05 +0000
Content-Type: text/plain; charset="utf-8"
Content-Transfer-Encoding: 8BIT
From:   marcel@linux-ng.de
Message-ID: <bf4aa2c82bfef19304d7a458a2a8fb28@linux-ng.de>
Subject: nfs-utils: rpc.svcgssd bug reading /etc/nfs.conf
To:     linux-nfs@vger.kernel.org
Precedence: bulk

Hi there,

please don't hesitate to direct me somewhere else in case this is not the right place to report
bugs concerning nfs-utils.

I found a bug in nfs-utils concerning the rpc.svcgssd daemon while I was trying to set the
principal name in /etc/nfs.conf:

[svcgssd]
principal=nfs/myhost.mydomain.de@MYDOMAIN.DE

However rpc.svcgssd refused to start - complaining about not being able to find the principal in
the keytab.
When specified on command line (using the -p option) things worked however.

So I took a look at the code and found the problem in nfs-utils-2.6.1/utils/gssd/svcgssd.c.
The problem seems to be here:

/* We don't need the config anymore */
conf_cleanup();

This is called right after parsing the config file(s), but before calling gssd_acquire_cred().
At the time it is called the variable "principal" does no longer contain the data read from the
config file.

Moving conf_cleanup() to the end of the code helps.

As I first encountered this on Ubuntu 22.04 I also opened a Launchpad bug report:
s. https://bugs.launchpad.net/ubuntu/+source/nfs-utils/+bug/1977745

Maybe someone can fix this for the next release.

Best regards,
Marcel