assuming we have lockless readers we should make sure they can only see expectations that have already been initialized. hlist_add_head_rcu acts as memory barrier, move it after timer setup. Theoretically we could crash due to a del_timer() on other cpu seeing garbage data. Signed-off-by: Florian Westphal <fw@xxxxxxxxx> --- Not seen in practice, however i think this race is real. Defer to nf-next if you think its not urgent. diff --git a/net/netfilter/nf_conntrack_expect.c b/net/netfilter/nf_conntrack_expect.c index e03d16ed550d..c034951597fe 100644 --- a/net/netfilter/nf_conntrack_expect.c +++ b/net/netfilter/nf_conntrack_expect.c @@ -368,12 +368,6 @@ static void nf_ct_expect_insert(struct nf_conntrack_expect *exp) /* two references : one for hash insert, one for the timer */ refcount_add(2, &exp->use); - hlist_add_head_rcu(&exp->lnode, &master_help->expectations); - master_help->expecting[exp->class]++; - - hlist_add_head_rcu(&exp->hnode, &nf_ct_expect_hash[h]); - net->ct.expect_count++; - setup_timer(&exp->timeout, nf_ct_expectation_timed_out, (unsigned long)exp); helper = rcu_dereference_protected(master_help->helper, @@ -384,6 +378,12 @@ static void nf_ct_expect_insert(struct nf_conntrack_expect *exp) } add_timer(&exp->timeout); + hlist_add_head_rcu(&exp->lnode, &master_help->expectations); + master_help->expecting[exp->class]++; + + hlist_add_head_rcu(&exp->hnode, &nf_ct_expect_hash[h]); + net->ct.expect_count++; + NF_CT_STAT_INC(net, expect_create); } -- 2.13.0 -- To unsubscribe from this list: send the line "unsubscribe netfilter-devel" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
