1 files changed, 24 insertions, 1 deletions

diff --git a/drivers/block/nbd.c b/drivers/block/nbd.c
index 6463d0e8d0ce..a853c65ac65d 100644
--- a/drivers/block/nbd.c
+++ b/drivers/block/nbd.c
@@ -52,6 +52,7 @@
 static DEFINE_IDR(nbd_index_idr);
 static DEFINE_MUTEX(nbd_index_mutex);
 static struct workqueue_struct *nbd_del_wq;
+static struct cred *nbd_cred;
 static int nbd_total_devices = 0;
 
 struct nbd_sock {
@@ -311,7 +312,7 @@ static void nbd_mark_nsock_dead(struct nbd_device *nbd, struct nbd_sock *nsock,
 		if (args) {
 			INIT_WORK(&args->work, nbd_dead_link_work);
 			args->index = nbd->index;
-			queue_work(system_wq, &args->work);
+			queue_work(system_percpu_wq, &args->work);
 		}
 	}
 	if (!nsock->dead) {
@@ -554,6 +555,7 @@ static int __sock_xmit(struct nbd_device *nbd, struct socket *sock, int send,
 	int result;
 	struct msghdr msg = {} ;
 	unsigned int noreclaim_flag;
+	const struct cred *old_cred;
 
 	if (unlikely(!sock)) {
 		dev_err_ratelimited(disk_to_dev(nbd->disk),
@@ -562,6 +564,8 @@ static int __sock_xmit(struct nbd_device *nbd, struct socket *sock, int send,
 		return -EINVAL;
 	}
 
+	old_cred = override_creds(nbd_cred);
+
 	msg.msg_iter = *iter;
 
 	noreclaim_flag = memalloc_noreclaim_save();
@@ -586,6 +590,8 @@ static int __sock_xmit(struct nbd_device *nbd, struct socket *sock, int send,
 
 	memalloc_noreclaim_restore(noreclaim_flag);
 
+	revert_creds(old_cred);
+
 	return result;
 }
 
@@ -1217,6 +1223,14 @@ static struct socket *nbd_get_socket(struct nbd_device *nbd, unsigned long fd,
 	if (!sock)
 		return NULL;
 
+	if (!sk_is_tcp(sock->sk) &&
+	    !sk_is_stream_unix(sock->sk)) {
+		dev_err(disk_to_dev(nbd->disk), "Unsupported socket: should be TCP or UNIX.\n");
+		*err = -EINVAL;
+		sockfd_put(sock);
+		return NULL;
+	}
+
 	if (sock->ops->shutdown == sock_no_shutdown) {
 		dev_err(disk_to_dev(nbd->disk), "Unsupported socket: shutdown callout must be supported.\n");
 		*err = -EINVAL;
@@ -2669,7 +2683,15 @@ static int __init nbd_init(void)
 		return -ENOMEM;
 	}
 
+	nbd_cred = prepare_kernel_cred(&init_task);
+	if (!nbd_cred) {
+		destroy_workqueue(nbd_del_wq);
+		unregister_blkdev(NBD_MAJOR, "nbd");
+		return -ENOMEM;
+	}
+
 	if (genl_register_family(&nbd_genl_family)) {
+		put_cred(nbd_cred);
 		destroy_workqueue(nbd_del_wq);
 		unregister_blkdev(NBD_MAJOR, "nbd");
 		return -EINVAL;
@@ -2724,6 +2746,7 @@ static void __exit nbd_cleanup(void)
 	/* Also wait for nbd_dev_remove_work() completes */
 	destroy_workqueue(nbd_del_wq);
 
+	put_cred(nbd_cred);
 	idr_destroy(&nbd_index_idr);
 	unregister_blkdev(NBD_MAJOR, "nbd");
 }