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

gpio: Fix resource leaks on errors in gpiochip_add_data_with_key()

Since commit aab5c6f20023 ("gpio: set device type for GPIO chips"),
`gdev->dev.release` is unset.  As a result, the reference count to
`gdev->dev` isn't dropped on the error handling paths.

Drop the reference on errors.

Also reorder the instructions to make the error handling simpler.
Now gpiochip_add_data_with_key() roughly looks like:

   >>> Some memory allocation.  Go to ERR ZONE 1 on errors.
   >>> device_initialize().

   gpiodev_release() takes over the responsibility for freeing the
   resources of `gdev->dev`.  The subsequent error handling paths
   shouldn't go through ERR ZONE 1 again which leads to double free.

   >>> Some initialization mainly on `gdev`.
   >>> The rest of initialization.  Go to ERR ZONE 2 on errors.
   >>> Chip registration success and exit.

   >>> ERR ZONE 2.  gpio_device_put() and exit.
   >>> ERR ZONE 1.