Eric Dumazet wrote:
> IPS_CONFIRMED_BIT is set under nf_conntrack_lock (in __nf_conntrack_confirm()),
> we probably want to add a synchronisation under ct->lock as well,
> or __nf_ct_refresh_acct() could set ct->timeout.expires to extra_jiffies,
> while a different cpu could confirm the conntrack.

Before the conntrack is confirmed, it is exclusively handled by a
single CPU. I agree that we need to make sure the IPS_CONFIRMED_BIT
is visible before we add the conntrack to the hash table since the
lookup is lockless, but simply moving the set_bit before the hash
insertion should be fine I think.