In the Linux kernel, the following vulnerability has been resolved: gpio: Fix resource leaks on...

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.