[PATCH AUTOSEL 4.4 19/21] USB: usb-skeleton: fix use-after-free after driver unbind

[Sasha Levin]

From: Johan Hovold <johan@xxxxxxxxxx>

[ Upstream commit 6353001852776e7eeaab4da78922d4c6f2b076af ]

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@xxxxxxxxxx>
Link: https://lore.kernel.org/r/20191009170944.30057-3-johan@xxxxxxxxxx
Signed-off-by: Greg Kroah-Hartman <gregkh@xxxxxxxxxxxxxxxxxxx>
Signed-off-by: Sasha Levin <sashal@xxxxxxxxxx>
---
 drivers/usb/usb-skeleton.c | 1 +
 1 file changed, 1 insertion(+)

diff --git a/drivers/usb/usb-skeleton.c b/drivers/usb/usb-skeleton.c
index 545d09b8081d5..be0fc67ce4f39 100644
--- a/drivers/usb/usb-skeleton.c
+++ b/drivers/usb/usb-skeleton.c
@@ -593,6 +593,7 @@ static void skel_disconnect(struct usb_interface *interface)
 	dev->interface = NULL;
 	mutex_unlock(&dev->io_mutex);
 
+	usb_kill_urb(dev->bulk_in_urb);
 	usb_kill_anchored_urbs(&dev->submitted);
 
 	/* decrement our usage count */
-- 
2.20.1