Re: [alsa-devel] [PATCH 1/5] Input: ambakmi - Convert to use devm_*()

On Sun, Mar 26, 2017 at 10:41:50PM +0800, Leo Yan wrote:

Convert driver to use devm_*() APIs so rely on driver model core layer to manage resources. This eliminates error path boilerplate and makes code neat.

This patch also fixes the memory leakage for 'kmi->io' when remove module.

No, it is not leaked, in fact, your patch introduces a use-after-free bug.

kmi->io is of type "struct serio", and this structure has an embedded "struct device". The lifetime of any structure containing a "struct device" is controlled by the lifetime of the struct device.

Once serio_register_port() has been called on it, it is up to the serio layer to free this structure.

Therefore, your patch creates a bug, and so it gets a NAK. There is no resource leakage here.