4 files changed, 42 insertions, 13 deletions

diff --git a/net/ipv4/netfilter/ipt_MASQUERADE.c b/net/ipv4/netfilter/ipt_MASQUERADE.c
index ce1512b02cb2..fd3f9e8a74da 100644
--- a/net/ipv4/netfilter/ipt_MASQUERADE.c
+++ b/net/ipv4/netfilter/ipt_MASQUERADE.c
@@ -81,9 +81,12 @@ static int __init masquerade_tg_init(void)
 	int ret;
 
 	ret = xt_register_target(&masquerade_tg_reg);
+	if (ret)
+		return ret;
 
-	if (ret == 0)
-		nf_nat_masquerade_ipv4_register_notifier();
+	ret = nf_nat_masquerade_ipv4_register_notifier();
+	if (ret)
+		xt_unregister_target(&masquerade_tg_reg);
 
 	return ret;
 }
diff --git a/net/ipv4/netfilter/nf_nat_masquerade_ipv4.c b/net/ipv4/netfilter/nf_nat_masquerade_ipv4.c
index a9d5e013e555..41327bb99093 100644
--- a/net/ipv4/netfilter/nf_nat_masquerade_ipv4.c
+++ b/net/ipv4/netfilter/nf_nat_masquerade_ipv4.c
@@ -147,28 +147,50 @@ static struct notifier_block masq_inet_notifier = {
 	.notifier_call	= masq_inet_event,
 };
 
-static atomic_t masquerade_notifier_refcount = ATOMIC_INIT(0);
+static int masq_refcnt;
+static DEFINE_MUTEX(masq_mutex);
 
-void nf_nat_masquerade_ipv4_register_notifier(void)
+int nf_nat_masquerade_ipv4_register_notifier(void)
 {
+	int ret = 0;
+
+	mutex_lock(&masq_mutex);
 	/* check if the notifier was already set */
-	if (atomic_inc_return(&masquerade_notifier_refcount) > 1)
-		return;
+	if (++masq_refcnt > 1)
+		goto out_unlock;
 
 	/* Register for device down reports */
-	register_netdevice_notifier(&masq_dev_notifier);
+	ret = register_netdevice_notifier(&masq_dev_notifier);
+	if (ret)
+		goto err_dec;
 	/* Register IP address change reports */
-	register_inetaddr_notifier(&masq_inet_notifier);
+	ret = register_inetaddr_notifier(&masq_inet_notifier);
+	if (ret)
+		goto err_unregister;
+
+	mutex_unlock(&masq_mutex);
+	return ret;
+
+err_unregister:
+	unregister_netdevice_notifier(&masq_dev_notifier);
+err_dec:
+	masq_refcnt--;
+out_unlock:
+	mutex_unlock(&masq_mutex);
+	return ret;
 }
 EXPORT_SYMBOL_GPL(nf_nat_masquerade_ipv4_register_notifier);
 
 void nf_nat_masquerade_ipv4_unregister_notifier(void)
 {
+	mutex_lock(&masq_mutex);
 	/* check if the notifier still has clients */
-	if (atomic_dec_return(&masquerade_notifier_refcount) > 0)
-		return;
+	if (--masq_refcnt > 0)
+		goto out_unlock;
 
 	unregister_netdevice_notifier(&masq_dev_notifier);
 	unregister_inetaddr_notifier(&masq_inet_notifier);
+out_unlock:
+	mutex_unlock(&masq_mutex);
 }
 EXPORT_SYMBOL_GPL(nf_nat_masquerade_ipv4_unregister_notifier);
diff --git a/net/ipv4/netfilter/nf_reject_ipv4.c b/net/ipv4/netfilter/nf_reject_ipv4.c
index 5cd06ba3535d..aa8304c618b8 100644
--- a/net/ipv4/netfilter/nf_reject_ipv4.c
+++ b/net/ipv4/netfilter/nf_reject_ipv4.c
@@ -102,6 +102,7 @@ EXPORT_SYMBOL_GPL(nf_reject_ip_tcphdr_put);
 /* Send RST reply */
 void nf_send_reset(struct net *net, struct sk_buff *oldskb, int hook)
 {
+	struct net_device *br_indev __maybe_unused;
 	struct sk_buff *nskb;
 	struct iphdr *niph;
 	const struct tcphdr *oth;
@@ -147,10 +148,11 @@ void nf_send_reset(struct net *net, struct sk_buff *oldskb, int hook)
 	 * build the eth header using the original destination's MAC as the
 	 * source, and send the RST packet directly.
 	 */
-	if (oldskb->nf_bridge) {
+	br_indev = nf_bridge_get_physindev(oldskb);
+	if (br_indev) {
 		struct ethhdr *oeth = eth_hdr(oldskb);
 
-		nskb->dev = nf_bridge_get_physindev(oldskb);
+		nskb->dev = br_indev;
 		niph->tot_len = htons(nskb->len);
 		ip_send_check(niph);
 		if (dev_hard_header(nskb, nskb->dev, ntohs(nskb->protocol),
diff --git a/net/ipv4/netfilter/nft_masq_ipv4.c b/net/ipv4/netfilter/nft_masq_ipv4.c
index f1193e1e928a..6847de1d1db8 100644
--- a/net/ipv4/netfilter/nft_masq_ipv4.c
+++ b/net/ipv4/netfilter/nft_masq_ipv4.c
@@ -69,7 +69,9 @@ static int __init nft_masq_ipv4_module_init(void)
 	if (ret < 0)
 		return ret;
 
-	nf_nat_masquerade_ipv4_register_notifier();
+	ret = nf_nat_masquerade_ipv4_register_notifier();
+	if (ret)
+		nft_unregister_expr(&nft_masq_ipv4_type);
 
 	return ret;
 }