USB: usb-skeleton: fix use-after-free after driver unbind

The driver failed to stop its read URB on disconnect, something which
could lead to a use-after-free in the completion handler after driver
unbind in case the character device has been closed.

Fixes: e7389cc9a7ff ("USB: skel_read really sucks royally")
Signed-off-by: Johan Hovold <johan@kernel.org>
Link: https://lore.kernel.org/r/20191009170944.30057-3-johan@kernel.org
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

diff --git a/drivers/usb/usb-skeleton.c b/drivers/usb/usb-skeleton.c
index c2843fc..be31178 100644 (file)
--- a/drivers/usb/usb-skeleton.c
+++ b/drivers/usb/usb-skeleton.c
@@ -575,6 +575,7 @@ static void skel_disconnect(struct usb_interface *interface)
        dev->disconnected = 1;
        mutex_unlock(&dev->io_mutex);
 
+       usb_kill_urb(dev->bulk_in_urb);
        usb_kill_anchored_urbs(&dev->submitted);
 
        /* decrement our usage count */