From mboxrd@z Thu Jan 1 00:00:00 1970 From: Pablo Neira Ayuso Subject: [PATCH 01/47] netfilter: expect: add to hash table after expect init Date: Mon, 4 Sep 2017 00:25:43 +0200 Message-ID: <1504477589-12045-2-git-send-email-pablo@netfilter.org> References: <1504477589-12045-1-git-send-email-pablo@netfilter.org> Cc: davem@davemloft.net, netdev@vger.kernel.org To: netfilter-devel@vger.kernel.org Return-path: In-Reply-To: <1504477589-12045-1-git-send-email-pablo@netfilter.org> Sender: netdev-owner@vger.kernel.org List-Id: netfilter-devel.vger.kernel.org From: Florian Westphal 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 Signed-off-by: Pablo Neira Ayuso --- net/netfilter/nf_conntrack_expect.c | 12 ++++++------ 1 file changed, 6 insertions(+), 6 deletions(-) diff --git a/net/netfilter/nf_conntrack_expect.c b/net/netfilter/nf_conntrack_expect.c index 899c2c36da13..2c63808bea96 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); } -- 2.1.4