From: Eric Dumazet Date: Wed, 25 Mar 2009 16:24:34 +0000 (+0100) Subject: netfilter: nf_conntrack: use hlist_add_head_rcu() in nf_conntrack_set_hashsize() X-Git-Url: http://www.pilppa.org/gitweb/gitweb.cgi?a=commitdiff_plain;h=78f3648601fdc7a8166748bbd6d0555a88efa24a;p=linux-2.6-omap-h63xx.git netfilter: nf_conntrack: use hlist_add_head_rcu() in nf_conntrack_set_hashsize() Using hlist_add_head() in nf_conntrack_set_hashsize() is quite dangerous. Without any barrier, one CPU could see a loop while doing its lookup. Its true new table cannot be seen by another cpu, but previous table is still readable. Signed-off-by: Eric Dumazet Signed-off-by: Patrick McHardy --- diff --git a/net/netfilter/nf_conntrack_core.c b/net/netfilter/nf_conntrack_core.c index 55befe59e1c..54e983f1389 100644 --- a/net/netfilter/nf_conntrack_core.c +++ b/net/netfilter/nf_conntrack_core.c @@ -1121,7 +1121,7 @@ int nf_conntrack_set_hashsize(const char *val, struct kernel_param *kp) struct nf_conntrack_tuple_hash, hnode); hlist_del_rcu(&h->hnode); bucket = __hash_conntrack(&h->tuple, hashsize, rnd); - hlist_add_head(&h->hnode, &hash[bucket]); + hlist_add_head_rcu(&h->hnode, &hash[bucket]); } } old_size = nf_conntrack_htable_size;