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Commit 83731671 authored by Pablo Neira Ayuso's avatar Pablo Neira Ayuso Committed by Patrick McHardy
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netfilter: ctnetlink: fix regression in expectation handling 



This patch fixes a regression (introduced by myself in commit 19abb7b0:
netfilter: ctnetlink: deliver events for conntracks changed from
userspace) that results in an expectation re-insertion since
__nf_ct_expect_check() may return 0 for expectation timer refreshing.

This patch also removes a unnecessary refcount bump that
pretended to avoid a possible race condition with event delivery
and expectation timers (as said, not needed since we hold a
reference to the object since until we finish the expectation
setup). This also merges nf_ct_expect_related_report() and
nf_ct_expect_related() which look basically the same.

Reported-by: default avatarPatrick McHardy <kaber@trash.net>
Signed-off-by: default avatarPablo Neira Ayuso <pablo@netfilter.org>
Signed-off-by: default avatarPatrick McHardy <kaber@trash.net>
parent 3ae16f13

include/net/netfilter/nf_conntrack_expect.h

+4 −1
Original line number Diff line number Diff line
@@ -99,9 +99,12 @@ void nf_ct_expect_init(struct nf_conntrack_expect *, unsigned int, u_int8_t, 
		       const union nf_inet_addr *,

		       u_int8_t, const __be16 *, const __be16 *);

void nf_ct_expect_put(struct nf_conntrack_expect *exp);

int nf_ct_expect_related(struct nf_conntrack_expect *expect);

int nf_ct_expect_related_report(struct nf_conntrack_expect *expect, 

				u32 pid, int report);

static inline int nf_ct_expect_related(struct nf_conntrack_expect *expect)

{

	return nf_ct_expect_related_report(expect, 0, 0);

}



#endif /*_NF_CONNTRACK_EXPECT_H*/

net/netfilter/nf_conntrack_expect.c

+6 −24
Original line number Diff line number Diff line
@@ -372,7 +372,7 @@ static inline int __nf_ct_expect_check(struct nf_conntrack_expect *expect) 
	struct net *net = nf_ct_exp_net(expect);

	struct hlist_node *n;

	unsigned int h;

	int ret = 0;

	int ret = 1;



	if (!master_help->helper) {

		ret = -ESHUTDOWN;
@@ -412,43 +412,25 @@ static inline int __nf_ct_expect_check(struct nf_conntrack_expect *expect) 
	return ret;

}



int nf_ct_expect_related(struct nf_conntrack_expect *expect)

int nf_ct_expect_related_report(struct nf_conntrack_expect *expect, 

				u32 pid, int report)

{

	int ret;



	spin_lock_bh(&nf_conntrack_lock);

	ret = __nf_ct_expect_check(expect);

	if (ret < 0)

	if (ret <= 0)

		goto out;



	ret = 0;

	nf_ct_expect_insert(expect);

	atomic_inc(&expect->use);

	spin_unlock_bh(&nf_conntrack_lock);

	nf_ct_expect_event(IPEXP_NEW, expect);

	nf_ct_expect_put(expect);

	nf_ct_expect_event_report(IPEXP_NEW, expect, pid, report);

	return ret;

out:

	spin_unlock_bh(&nf_conntrack_lock);

	return ret;

}

EXPORT_SYMBOL_GPL(nf_ct_expect_related);



int nf_ct_expect_related_report(struct nf_conntrack_expect *expect, 

				u32 pid, int report)

{

	int ret;



	spin_lock_bh(&nf_conntrack_lock);

	ret = __nf_ct_expect_check(expect);

	if (ret < 0)

		goto out;

	nf_ct_expect_insert(expect);

out:

	spin_unlock_bh(&nf_conntrack_lock);

	if (ret == 0)

		nf_ct_expect_event_report(IPEXP_NEW, expect, pid, report);

	return ret;

}

EXPORT_SYMBOL_GPL(nf_ct_expect_related_report);



#ifdef CONFIG_PROC_FS