>> Thanks. Can you please test this patch and let me know if it works
>> for you?
> OK, applied, but what now? If you are sure that you have fixed the
> bug, but just want me to run a "crash test" before commiting, then all
> I can say is there's nothing wrong yet, I'll keep running the patch
> until something comes up, like a panic (and report it). Otherwise I
> can't test wether the patch does avoid the non-reproducable panic.
I believe (without reproducing it) that the problem was
igmp_v3_cancel_link_timers() not cancelling the v3 link timer in all
situations. The panic you saw was due to a v3 timer firing even though
the timer should have been cancelled by reception of the v2 query from
your university's LAN router.
The RFC could be worded better about how the 'Older Querier' timer is
heeded -- on re-reading it makes sense not to flap between IGMP versions
-- the oldest version in use on the link persists for up to 260s with
the default protocol timers, only switching version after the timer
expires is best as it provides some built-in hysteresis.
It sounds like the fix is OK. Obviously, let me know if you see problems
again, I've checked the patch into HEAD now.