[OpenAFS] fileserver crash, potential DOS

[Marco Foglia]

> I'm curious if anyone else has seen this and maybe add any useful
> info.  Earlier this week one of our fileservers began crashing
> periodically and today a 2nd one began doing so.  Both are Linux
> 2.2.16-3 with afs3.6 2.5.  One is smp, one not.  Our other servers,
> all AIX have not (yet) experienced this.
> ...

We have the same setup here (afs3.6 2.5 on Redhat 6.2/2.2.16-3) and
the same problem.

The problem seems to be reproducible by changing the ip address of
a client during a connection. This sounds rather bizarre but it 
can happen if you connect through a dialup connection, the link
goes down and then you get another ip address when you reconnect.

We switched to openafs 1.0.3 on the file servers to weeks ago and
the problem seems to be gone.
 
BTW: There is (at least) one other problem with the linux file server
related to backup volumes and copyonwrite. The bug can corrupt the
rw volume under unreproducible circumstances. So be warned.

Marco