[PATCH 5.4 257/309] virtio_balloon: Fix memory leaks on errors in virtballoon_probe()

[Greg Kroah-Hartman]

From: David Hildenbrand <david@xxxxxxxxxx>

commit 1ad6f58ea9364b0a5d8ae06249653ac9304a8578 upstream.

We forget to put the inode and unmount the kernfs used for compaction.

Fixes: 71994620bb25 ("virtio_balloon: replace oom notifier with shrinker")
Cc: "Michael S. Tsirkin" <mst@xxxxxxxxxx>
Cc: Jason Wang <jasowang@xxxxxxxxxx>
Cc: Wei Wang <wei.w.wang@xxxxxxxxx>
Cc: Liang Li <liang.z.li@xxxxxxxxx>
Signed-off-by: David Hildenbrand <david@xxxxxxxxxx>
Link: https://lore.kernel.org/r/20200205163402.42627-3-david@xxxxxxxxxx
Signed-off-by: Michael S. Tsirkin <mst@xxxxxxxxxx>
Signed-off-by: Greg Kroah-Hartman <gregkh@xxxxxxxxxxxxxxxxxxx>

---
 drivers/virtio/virtio_balloon.c |   13 +++++++++----
 1 file changed, 9 insertions(+), 4 deletions(-)

--- a/drivers/virtio/virtio_balloon.c
+++ b/drivers/virtio/virtio_balloon.c
@@ -900,8 +900,7 @@ static int virtballoon_probe(struct virt
 	vb->vb_dev_info.inode = alloc_anon_inode(balloon_mnt->mnt_sb);
 	if (IS_ERR(vb->vb_dev_info.inode)) {
 		err = PTR_ERR(vb->vb_dev_info.inode);
-		kern_unmount(balloon_mnt);
-		goto out_del_vqs;
+		goto out_kern_unmount;
 	}
 	vb->vb_dev_info.inode->i_mapping->a_ops = &balloon_aops;
 #endif
@@ -912,13 +911,13 @@ static int virtballoon_probe(struct virt
 		 */
 		if (virtqueue_get_vring_size(vb->free_page_vq) < 2) {
 			err = -ENOSPC;
-			goto out_del_vqs;
+			goto out_iput;
 		}
 		vb->balloon_wq = alloc_workqueue("balloon-wq",
 					WQ_FREEZABLE | WQ_CPU_INTENSIVE, 0);
 		if (!vb->balloon_wq) {
 			err = -ENOMEM;
-			goto out_del_vqs;
+			goto out_iput;
 		}
 		INIT_WORK(&vb->report_free_page_work, report_free_page_func);
 		vb->cmd_id_received_cache = VIRTIO_BALLOON_CMD_ID_STOP;
@@ -952,6 +951,12 @@ static int virtballoon_probe(struct virt
 out_del_balloon_wq:
 	if (virtio_has_feature(vdev, VIRTIO_BALLOON_F_FREE_PAGE_HINT))
 		destroy_workqueue(vb->balloon_wq);
+out_iput:
+#ifdef CONFIG_BALLOON_COMPACTION
+	iput(vb->vb_dev_info.inode);
+out_kern_unmount:
+	kern_unmount(balloon_mnt);
+#endif
 out_del_vqs:
 	vdev->config->del_vqs(vdev);
 out_free_vb: