CVE-2025-21838

In the Linux kernel, the following vulnerability has been resolved:

usb: gadget: core: flush gadget workqueue after device removal

device_del() can lead to new work being scheduled in gadget->work
workqueue. This is observed, for example, with the dwc3 driver with the
following call stack:
device_del()
gadget_unbind_driver()
usb_gadget_disconnect_locked()
dwc3_gadget_pullup()
dwc3_gadget_soft_disconnect()
usb_gadget_set_state()
schedule_work(&gadget->work)

Move flush_work() after device_del() to ensure the workqueue is cleaned
up.