usb: gadget: udc-core: fix a regression during gadget driver unbinding

This patch (as1666) fixes a regression in the UDC core.  The core
takes care of unbinding gadget drivers, and it does the unbinding
before telling the UDC driver to turn off the controller hardware.
When the call to the udc_stop callback is made, the gadget no longer
has a driver.  The callback routine should not be invoked with a
pointer to the old driver; doing so can cause problems (such as
use-after-free accesses in net2280).

This patch should be applied, with appropriate context changes, to all
the stable kernels going back to 3.1.

Signed-off-by: Alan Stern <stern@rowland.harvard.edu>
CC: <stable@vger.kernel.org>
Signed-off-by: Felipe Balbi <balbi@ti.com>

diff --git a/drivers/usb/gadget/udc-core.c b/drivers/usb/gadget/udc-core.c
index 2a9cd369f71cd857cce96f48acb4b600a828c981..f8f62c3ed65e7a468b97f7348aac97ea133bbcf1 100644 (file)
--- a/drivers/usb/gadget/udc-core.c
+++ b/drivers/usb/gadget/udc-core.c
@@ -216,7 +216,7 @@ static void usb_gadget_remove_driver(struct usb_udc *udc)
        usb_gadget_disconnect(udc->gadget);
        udc->driver->disconnect(udc->gadget);
        udc->driver->unbind(udc->gadget);
-       usb_gadget_udc_stop(udc->gadget, udc->driver);
+       usb_gadget_udc_stop(udc->gadget, NULL);
 
        udc->driver = NULL;
        udc->dev.driver = NULL;