[OpenAFS] NULL pointer dereference

[Benjamin Kaduk]

On Wed, 21 Jan 2015, Markus Koeberl wrote:

> Today my client crashed while reading emails with kmail/kontact.
> I am using a backported version 1.6.9-2 from debian jessie which additionally include the patch for reporting 2TB disk free. We use this version on all our client starting from 14 Jun 2014 and its the first time this happened. I guess there is no easy way to reproduce it.
> I found nothing relevant in the changelog till 1.6.10-3 and 1.6.11~pre1-1 which are the newest versions for debian.
>
> dmesg output:
>
> [4367269.820966] BUG: unable to handle kernel NULL pointer dereference at 0000000000000038
> [4367269.820971] IP: [<ffffffffa0914240>] afs_linux_dentry_revalidate+0x25/0x46f [openafs]
> [4367269.820985] PGD 29aede067 PUD 2695a6067 PMD 0
> [4367269.820988] Oops: 0000 [#1] SMP

This looks a lot like
https://rt.central.org/rt/Ticket/Display.html?id=131967, which we expect
to be fixed in 1.6.11pre2 (due out "soon").

I forget whether gerrit 11643 or 11464 is believed to be the real fix;
11616 is an additional band-aid that would not resolve the actual problem.

-Ben