Linux Driver Verification

The functions usb_get_urb and usb_free_urb are not dual actually, because usb_free_urb may be called without usb_get_urb
and the function usb_get_urb does not allocates memory, so it can't be called without usb_alloc_urb.
Therefore the topic of the bug is correct, but the right description of the bug is that for each call usb_get_urb() with nonzero parameter there are must be the call to usb_free_urb with the same parameter.

If you have any unsafes with usb_get_urb, it will be helpful to check that the call to usb_alloc_urb was performed before usb_get_urb. Without it the false unsafes will not go out even with the new model function.