Bluetooth: virtio_bt: Fix use-after-free and memory leak in probe error paths

When virtbt_open_vdev() fails in virtbt_probe(), hci_free_dev(hdev) is
called without first calling hci_unregister_dev(hdev). Since
hci_register_dev() already succeeded, the HCI device remains registered
while its memory is freed, leading to a use-after-free when accessed
via sysfs or HCI sockets.

Additionally, the probe function leaks the virtio_bluetooth structure
(vbt) in several error paths:
  - When virtio_find_vqs() fails, vbt is not freed.
  - When hci_alloc_dev() or hci_register_dev() fails, vbt is not freed.
  - When virtbt_open_vdev() fails, vbt is not freed.

Furthermore, when virtbt_open_vdev() fails after virtio_device_ready()
has been called, the device is left live (DRIVER_OK set) while its
virtqueues are torn down, and any scheduled work is not flushed,
potentially allowing a use-after-free from device-initiated callbacks.

Fix all of these by restructuring the error labels to properly unwind
in reverse order of the allocation/registration sequence. The new
labels err_del_vqs and err_free_vbt ensure that del_vqs and kfree(vbt)
are called as appropriate for each failure point. For the
virtbt_open_vdev() failure path, call virtio_reset_device() and
virtbt_close_vdev() before unregistering the HCI device, matching the
cleanup pattern in virtbt_remove().

Signed-off-by: ZhaoJinming <zhaojinming@uniontech.com>
Signed-off-by: Luiz Augusto von Dentz <luiz.von.dentz@intel.com>

1 files changed, 13 insertions, 8 deletions

diff --git a/drivers/bluetooth/virtio_bt.c b/drivers/bluetooth/virtio_bt.c
index c20d54088c8c..8c55b538deef 100644
--- a/drivers/bluetooth/virtio_bt.c
+++ b/drivers/bluetooth/virtio_bt.c
@@ -315,12 +315,12 @@ static int virtbt_probe(struct virtio_device *vdev)
 
 	err = virtio_find_vqs(vdev, VIRTBT_NUM_VQS, vbt->vqs, vqs_info, NULL);
 	if (err)
-		return err;
+		goto err_free_vbt;
 
 	hdev = hci_alloc_dev();
 	if (!hdev) {
 		err = -ENOMEM;
-		goto failed;
+		goto err_del_vqs;
 	}
 
 	vbt->hdev = hdev;
@@ -390,20 +390,25 @@ static int virtbt_probe(struct virtio_device *vdev)
 	if (hci_register_dev(hdev) < 0) {
 		hci_free_dev(hdev);
 		err = -EBUSY;
-		goto failed;
+		goto err_del_vqs;
 	}
 
 	virtio_device_ready(vdev);
 	err = virtbt_open_vdev(vbt);
-	if (err)
-		goto open_failed;
+	if (err) {
+		hci_unregister_dev(hdev);
+		virtio_reset_device(vdev);
+		virtbt_close_vdev(vbt);
+		hci_free_dev(hdev);
+		goto err_del_vqs;
+	}
 
 	return 0;
 
-open_failed:
-	hci_free_dev(hdev);
-failed:
+err_del_vqs:
 	vdev->config->del_vqs(vdev);
+err_free_vbt:
+	kfree(vbt);
 	return err;
 }