I have implemented a custom extension for conntrack. It is basically extra pointer which resides in "struct nf_conn". The pointer references a slab buffer and it is used/modified in custom netfilter match extension. I'm not sure whether it is possible that different skbs with the same nf_conn can be simultaneously handled on different CPUs. My question is, should I protect the buffer (custom_buffer_ptr) with a spinlock in the match callback of the extension (struct xt_match.match)?
