Re: [syzbot] [rdma] general protection fault in kernel_sock_shutdown (4)

[Zhu Yanjun]

diff --git a/drivers/infiniband/core/nldev.c 
b/drivers/infiniband/core/nldev.c
index 3cb3cb7629fe..96c745d5bac4 100644
--- a/drivers/infiniband/core/nldev.c
+++ b/drivers/infiniband/core/nldev.c
@@ -1816,8 +1816,6 @@ static int nldev_newlink(struct sk_buff *skb, 
struct nlmsghdr *nlh,
 	return err;
 }

-static DEFINE_MUTEX(nldev_dellink_mutex);
-
 static int nldev_dellink(struct sk_buff *skb, struct nlmsghdr *nlh,
 			  struct netlink_ext_ack *extack)
 {
@@ -1848,9 +1846,7 @@ static int nldev_dellink(struct sk_buff *skb, 
struct nlmsghdr *nlh,
 	 * implicitly scoped to the driver supporting dynamic link deletion 
like RXE.
 	 */
 	if (device->link_ops && device->link_ops->dellink) {
-		mutex_lock(&nldev_dellink_mutex);
 		err = device->link_ops->dellink(device);
-		mutex_unlock(&nldev_dellink_mutex);
 		if (err)
 			return err;
 	}
diff --git a/drivers/infiniband/sw/rxe/rxe_net.c 
b/drivers/infiniband/sw/rxe/rxe_net.c
index 50a2cb5405e2..92847e955ca2 100644
--- a/drivers/infiniband/sw/rxe/rxe_net.c
+++ b/drivers/infiniband/sw/rxe/rxe_net.c
@@ -642,6 +642,8 @@ static void rxe_sock_put(struct sock *sk,
 	}
 }

+static DEFINE_MUTEX(rxe_net_del_mutex);
+
 void rxe_net_del(struct ib_device *dev)
 {
 	struct rxe_dev *rxe = container_of(dev, struct rxe_dev, ib_dev);
@@ -649,9 +651,10 @@ void rxe_net_del(struct ib_device *dev)
 	struct sock *sk;
 	struct net *net;

+	mutex_lock(&rxe_net_del_mutex);
 	ndev = rxe_ib_device_get_netdev(&rxe->ib_dev);
 	if (!ndev)
-		return;
+		goto out;

 	net = dev_net(ndev);

@@ -664,6 +667,8 @@ void rxe_net_del(struct ib_device *dev)
 		rxe_sock_put(sk, rxe_ns_pernet_set_sk6, net);

 	dev_put(ndev);
+out:
+	mutex_unlock(&rxe_net_del_mutex);
 }

 static void rxe_port_event(struct rxe_dev *rxe,