Possible 'destroy' paths for conntracks?

[Justin Schoeman <justin@expertron.co.za>]

[I am not on the list, so please CC me any answers.]

Hi all,

I am trying to locate a memory leak, either induced by, or agravated by 
the l7-filter.

Using the slab debugger, I see that the memory that is leaking are the 
app_data and/or app_proto fields that are kmalloc'ed in the 'match' method.

These are then (supposed to be) kfree'ed in the destroy_conntrack 
function, but they are apparently not destroyed, as even after most 
active connections have closed/timed out (/proc/net/ip_conntrack is 
practically empty), there are still thousands of these kmalloced memory 
regions left.

At the moment, I am assuming that there are multiple possible paths for 
a conntrack to be destroyed, and l7-filter is just missing some.  Is 
this true?  If so, what are all the possible destructors, or is there 
one single (better) place to clean up per-conntrack specific memory?

Thanks,
Justin