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

[Edward Adam Davis]

#syz test

diff --git a/drivers/infiniband/core/nldev.c b/drivers/infiniband/core/nldev.c
index 96c745d5bac4..3cb3cb7629fe 100644
--- a/drivers/infiniband/core/nldev.c
+++ b/drivers/infiniband/core/nldev.c
@@ -1816,6 +1816,8 @@ 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)
 {
@@ -1846,7 +1848,9 @@ 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;
 	}