2 files changed, 17 insertions, 18 deletions

diff --git a/net/netlink/af_netlink.c b/net/netlink/af_netlink.c
index 380f95aacdec..ada47e59647a 100644
--- a/net/netlink/af_netlink.c
+++ b/net/netlink/af_netlink.c
@@ -594,7 +594,10 @@ static int netlink_insert(struct sock *sk, u32 portid)
 
 	/* We need to ensure that the socket is hashed and visible. */
 	smp_wmb();
-	nlk_sk(sk)->bound = portid;
+	/* Paired with lockless reads from netlink_bind(),
+	 * netlink_connect() and netlink_sendmsg().
+	 */
+	WRITE_ONCE(nlk_sk(sk)->bound, portid);
 
 err:
 	release_sock(sk);
@@ -1012,7 +1015,8 @@ static int netlink_bind(struct socket *sock, struct sockaddr *addr,
 	if (nlk->ngroups < BITS_PER_LONG)
 		groups &= (1UL << nlk->ngroups) - 1;
 
-	bound = nlk->bound;
+	/* Paired with WRITE_ONCE() in netlink_insert() */
+	bound = READ_ONCE(nlk->bound);
 	if (bound) {
 		/* Ensure nlk->portid is up-to-date. */
 		smp_rmb();
@@ -1098,8 +1102,9 @@ static int netlink_connect(struct socket *sock, struct sockaddr *addr,
 
 	/* No need for barriers here as we return to user-space without
 	 * using any of the bound attributes.
+	 * Paired with WRITE_ONCE() in netlink_insert().
 	 */
-	if (!nlk->bound)
+	if (!READ_ONCE(nlk->bound))
 		err = netlink_autobind(sock);
 
 	if (err == 0) {
@@ -1888,7 +1893,8 @@ static int netlink_sendmsg(struct socket *sock, struct msghdr *msg, size_t len)
 		dst_group = nlk->dst_group;
 	}
 
-	if (!nlk->bound) {
+	/* Paired with WRITE_ONCE() in netlink_insert() */
+	if (!READ_ONCE(nlk->bound)) {
 		err = netlink_autobind(sock);
 		if (err)
 			goto out;
@@ -2545,13 +2551,15 @@ int nlmsg_notify(struct sock *sk, struct sk_buff *skb, u32 portid,
 		/* errors reported via destination sk->sk_err, but propagate
 		 * delivery errors if NETLINK_BROADCAST_ERROR flag is set */
 		err = nlmsg_multicast(sk, skb, exclude_portid, group, flags);
+		if (err == -ESRCH)
+			err = 0;
 	}
 
 	if (report) {
 		int err2;
 
 		err2 = nlmsg_unicast(sk, skb, portid);
-		if (!err || err == -ESRCH)
+		if (!err)
 			err = err2;
 	}
 
diff --git a/net/netlink/genetlink.c b/net/netlink/genetlink.c
index 2d6fdf40df66..1afca2a6c2ac 100644
--- a/net/netlink/genetlink.c
+++ b/net/netlink/genetlink.c
@@ -40,14 +40,6 @@ void genl_unlock(void)
 }
 EXPORT_SYMBOL(genl_unlock);
 
-#ifdef CONFIG_LOCKDEP
-bool lockdep_genl_is_held(void)
-{
-	return lockdep_is_held(&genl_mutex);
-}
-EXPORT_SYMBOL(lockdep_genl_is_held);
-#endif
-
 static void genl_lock_all(void)
 {
 	down_write(&cb_lock);
@@ -1485,6 +1477,7 @@ int genlmsg_multicast_allns(const struct genl_family *family,
 {
 	if (WARN_ON_ONCE(group >= family->n_mcgrps))
 		return -EINVAL;
+
 	group = family->mcgrp_offset + group;
 	return genlmsg_mcast(skb, portid, group, flags);
 }
@@ -1495,14 +1488,12 @@ void genl_notify(const struct genl_family *family, struct sk_buff *skb,
 {
 	struct net *net = genl_info_net(info);
 	struct sock *sk = net->genl_sock;
-	int report = 0;
-
-	if (info->nlhdr)
-		report = nlmsg_report(info->nlhdr);
 
 	if (WARN_ON_ONCE(group >= family->n_mcgrps))
 		return;
+
 	group = family->mcgrp_offset + group;
-	nlmsg_notify(sk, skb, info->snd_portid, group, report, flags);
+	nlmsg_notify(sk, skb, info->snd_portid, group,
+		     nlmsg_report(info->nlhdr), flags);
 }
 EXPORT_SYMBOL(genl_notify);