Comment 6 for bug 415766

As Marc notes, this is SELinux denying access to the AFS disk cache. Sadly, when OpenAFS cannot open files it expects to see in its cache, it panics, rather than returning a graceful error to userspace.

I'm not familiar with what Ubuntu's SELinux policy looks like (this comment is a drive-by from an OpenAFS developer), but it would be worth investigating there to see what rules it has with respect to /var/cache/openafs