ipt_owner panic on 2.6.10-1.12_FC2

ipt_owner panic on 2.6.10-1.12_FC2

[Fredrik Tolf]

Hi!

On the Linux router I'm running, I use the ipt_owner iptables module,
and since a few kernel versions back, I've begun getting kernel panics
in the ipt_owner module.

Unfortunately, the start of it coincided with a CPU upgrade of the
router, so at first I thought it was a hardware failure. Therefore, I
didn't note on what kernel version it first started happening. This
kernel version is a stock Fedora Core 2 kernel from FC's yum repo,
2.6.10-1.12_FC2.

Anyhow, I'm getting this panic message:
Kernel panic - not syncing: net/ipv4/netfilter/ipt_owner.c:38:
spin_lock(kernel/fork.c:ca2dc044) already locked by fs/file_table.c/153

I've got a long stack trace in the same photograph that I took of the
monitor. Please tell me if you want it. I've seen the file and source
line of the "already locked by" vary (such as "already locked by
fs/open.c/someline"... it was somewhere in sys_close() at that time), so
it doesn't seem to be depending on that.

Not sure if this is the kind of error that goes to the LKML. Please tell
me if I got it wrong.

Also, if anyone has the time, please clear up this confusion for me -- I
assume from the message that this panic is because one thread tries to
lock the same lock twice, but I've always thought that Linux spinlocks
are recursively lockable. Am I just wrong about them being recursively
lockable, or does this panic have another cause?

Thanks for your time!

Fredrik Tolf