Re: ctnetlink kernel dump while running multiple libnfct clients

[Pablo Neira Ayuso <pablo@netfilter.org>]

On 30/03/11 00:44, Sam Roberts wrote:
> When this happened, I was running the prototype conntracker, and
> several instances of conntrack -E (for each table). I typed a
> conntrack -L command, and the kernel died after I hit ENTER. Could be
> unrelated to that, but seems suspiciously coincidental that the
> backtrace shown reflects something I did (it looks related to printing
> conntracks). Still, you would know better than me what the kernel does
> when things go wrong.

I think I've got the problematic scenario: the master ct is released
while there are still user-space expectations. In that case, the
expectations still point to the master, once they've been released. Once
the expectations expire, we dereference to the master ct which is not
valid anymore.

I'll send a patch to fix this.