Comment 25 for bug 293705

User-Agent: Mozilla/5.0 (X11; U; Linux x86_64; en-US; rv:1.9.2.6) Gecko/20100628 Ubuntu/10.04 (lucid) Firefox/3.6.6

SSH by default deletes Kerberos credentials when a user logs out.

If the user left a program running (for instance via screen), and if Kerberos credentials are needed to access the home directories (kerberized NFS), rpc.gssd will fail to obtain Kerberos credentials.

The problem is that it generates excessive amounts of warnings in the syslog to this effect (about 1100 wrnings per second), which then quickly fill up the hard drive.

Reproducible: Always

Steps to Reproduce:
1. Log in (via SSH) to host that mounts home directory via kerberized NFS
2. Start screen with some process accessing the home dir inside
3. Detach screen
4. Close SSH session
5. Wait for rpc.gssd credentials cache to expire
Actual Results:
When the process still running on the target host tries to access the home directory, rpc.gssd will try and fail to obtain kerberos credentials for the user. It will then spam the syslog with the following warning
----
<date> <hostname> rpc.gssd[<pid>]: WARNING: Failed to create krb5 context for user with uid <uid> for server <other hostname>
----
This is repeated ad infinitum until the offending process is killed manually. The logfile otherwise quickly fills up the partition.

Expected Results:
Maybe one warning or no warning at all should be emitted (the latter is the case for *expired* credentials). See also https://bugs.launchpad.net/ubuntu/+source/nfs-utils/+bug/293705 for the case of expired credentials.

A fix fo this should probably also be coordinated with upstream.