Affected: Linux

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.