1 files changed, 18 insertions, 7 deletions

diff --git a/net/netfilter/ipvs/ip_vs_sync.c b/net/netfilter/ipvs/ip_vs_sync.c
index a4a78c4b06de..0c1bc654245c 100644
--- a/net/netfilter/ipvs/ip_vs_sync.c
+++ b/net/netfilter/ipvs/ip_vs_sync.c
@@ -1717,6 +1717,8 @@ static int sync_thread_backup(void *data)
 {
 	struct ip_vs_sync_thread_data *tinfo = data;
 	struct netns_ipvs *ipvs = tinfo->ipvs;
+	struct sock *sk = tinfo->sock->sk;
+	struct udp_sock *up = udp_sk(sk);
 	int len;
 
 	pr_info("sync thread started: state = BACKUP, mcast_ifn = %s, "
@@ -1724,12 +1726,14 @@ static int sync_thread_backup(void *data)
 		ipvs->bcfg.mcast_ifn, ipvs->bcfg.syncid, tinfo->id);
 
 	while (!kthread_should_stop()) {
-		wait_event_interruptible(*sk_sleep(tinfo->sock->sk),
-			 !skb_queue_empty(&tinfo->sock->sk->sk_receive_queue)
-			 || kthread_should_stop());
+		wait_event_interruptible(*sk_sleep(sk),
+					 !skb_queue_empty_lockless(&sk->sk_receive_queue) ||
+					 !skb_queue_empty_lockless(&up->reader_queue) ||
+					 kthread_should_stop());
 
 		/* do we have data now? */
-		while (!skb_queue_empty(&(tinfo->sock->sk->sk_receive_queue))) {
+		while (!skb_queue_empty_lockless(&sk->sk_receive_queue) ||
+		       !skb_queue_empty_lockless(&up->reader_queue)) {
 			len = ip_vs_receive(tinfo->sock, tinfo->buf,
 					ipvs->bcfg.sync_maxlen);
 			if (len <= 0) {
@@ -1762,6 +1766,10 @@ int start_sync_thread(struct netns_ipvs *ipvs, struct ipvs_sync_daemon_cfg *c,
 	IP_VS_DBG(7, "Each ip_vs_sync_conn entry needs %zd bytes\n",
 		  sizeof(struct ip_vs_sync_conn_v0));
 
+	/* increase the module use count */
+	if (!ip_vs_use_count_inc())
+		return -ENOPROTOOPT;
+
 	/* Do not hold one mutex and then to block on another */
 	for (;;) {
 		rtnl_lock();
@@ -1892,9 +1900,6 @@ int start_sync_thread(struct netns_ipvs *ipvs, struct ipvs_sync_daemon_cfg *c,
 	mutex_unlock(&ipvs->sync_mutex);
 	rtnl_unlock();
 
-	/* increase the module use count */
-	ip_vs_use_count_inc();
-
 	return 0;
 
 out:
@@ -1924,11 +1929,17 @@ out:
 		}
 		kfree(ti);
 	}
+
+	/* decrease the module use count */
+	ip_vs_use_count_dec();
 	return result;
 
 out_early:
 	mutex_unlock(&ipvs->sync_mutex);
 	rtnl_unlock();
+
+	/* decrease the module use count */
+	ip_vs_use_count_dec();
 	return result;
 }