diff --git a/net/bluetooth/hci_sync.c b/net/bluetooth/hci_sync.c
index 9eca6757d44f..014ceaefd788 100644
--- a/net/bluetooth/hci_sync.c
+++ b/net/bluetooth/hci_sync.c
@@ -5497,7 +5497,9 @@ int hci_dev_open_sync(struct hci_dev *hdev)
 		goto done;
 	}
 
+	hci_dev_lock(hdev);
 	hci_devcd_reset(hdev);
+	hci_dev_unlock(hdev);
 
 	set_bit(HCI_RUNNING, &hdev->flags);
 	hci_sock_dev_event(hdev, HCI_DEV_OPEN);