1 files changed, 4 insertions, 0 deletions

diff --git a/drivers/usb/image/mdc800.c b/drivers/usb/image/mdc800.c
index 63a84bbc310d..d308afd06935 100644
--- a/drivers/usb/image/mdc800.c
+++ b/drivers/usb/image/mdc800.c
@@ -565,11 +565,15 @@ static void mdc800_usb_disconnect (struct usb_interface *intf)
 
                 usb_deregister_dev(intf, &mdc800_class);
 
+                /* must be under lock to make sure no URB
+                   is submitted after usb_kill_urb() */
+                mutex_lock(&mdc800->io_lock);
                 mdc800->state=NOT_CONNECTED;
 
                 usb_kill_urb(mdc800->irq_urb);
                 usb_kill_urb(mdc800->write_urb);
                 usb_kill_urb(mdc800->download_urb);
+                mutex_unlock(&mdc800->io_lock);
 
                 mdc800->dev = NULL;
                 usb_set_intfdata(intf, NULL);