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Commit 56a97e70 authored by Florian Westphal's avatar Florian Westphal Committed by Pablo Neira Ayuso
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netfilter: expect: add to hash table after expect init 



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: default avatarFlorian Westphal <fw@strlen.de>
Signed-off-by: default avatarPablo Neira Ayuso <pablo@netfilter.org>
parent 7a68ada6

net/netfilter/nf_conntrack_expect.c

+6 −6
Original line number Diff line number Diff line
@@ -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);

}