Commit 78f36486 authored Mar 25, 2009 by Eric Dumazet Committed by Patrick McHardy Mar 25, 2009

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 <dada1@cosmosbay.com>
Signed-off-by: Patrick McHardy <kaber@trash.net>

parent a9a9adfe

net/netfilter/nf_conntrack_core.c

+1 −1

Original line number	Diff line number	Diff line
		@@ -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;