1 files changed, 10 insertions, 8 deletions

diff --git a/net/netlink/af_netlink.c b/net/netlink/af_netlink.c
index 4f5f93fd6802..1a19d179e913 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);
@@ -704,9 +707,7 @@ static int netlink_create(struct net *net, struct socket *sock, int protocol,
 	if (err < 0)
 		goto out_module;
 
-	local_bh_disable();
 	sock_prot_inuse_add(net, &netlink_proto, 1);
-	local_bh_enable();
 
 	nlk = nlk_sk(sock->sk);
 	nlk->module = module;
@@ -806,9 +807,7 @@ static int netlink_release(struct socket *sock)
 		netlink_table_ungrab();
 	}
 
-	local_bh_disable();
 	sock_prot_inuse_add(sock_net(sk), &netlink_proto, -1);
-	local_bh_enable();
 	call_rcu(&nlk->rcu, deferred_put_nlk_sk);
 	return 0;
 }
@@ -1012,7 +1011,8 @@ 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 +1098,9 @@ 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) {
@@ -1869,7 +1870,8 @@ 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;