tree bf4a9a6497dec37fdd4a31999cb218277e2ba656
parent 279072882dc0149e5740dace075e1a49f087046d
author Jozsef Kadlecsik <kadlec@blackhole.kfki.hu> 1330080349 +0100
committer Pablo Neira Ayuso <pablo@netfilter.org> 1330082655 +0100

netfilter: ctnetlink: fix soft lockup when netlink adds new entries (v2)

Marcell Zambo and Janos Farago noticed and reported that when
new conntrack entries are added via netlink and the conntrack table
gets full, soft lockup happens. This is because the nf_conntrack_lock
is held while nf_conntrack_alloc is called, which is in turn wants
to lock nf_conntrack_lock while evicting entries from the full table.

The patch fixes the soft lockup with limiting the holding of the
nf_conntrack_lock to the minimum, where it's absolutely required.
It required to extend (and thus change) nf_conntrack_hash_insert
so that it makes sure conntrack and ctnetlink do not add the same entry
twice to the conntrack table.

Signed-off-by: Jozsef Kadlecsik <kadlec@blackhole.kfki.hu>
Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>