Re: [PATCH 0/6] leds: fix broken devres usage

Andy Shevchenko
2020-06-01T13:51:13Z

On Mon, Jun 1, 2020 at 4:42 PM Johan Hovold <johan@kernel.org> wrote:
>
> Several MFD child drivers register their class devices directly under
> the parent device (about half of the MFD LED drivers do so).
>
> This means you cannot blindly do devres conversions so that
> deregistration ends up being tied to the parent device, something which
> leads to use-after-free on driver unbind when the class device is
> released while still being registered (and, for example, oopses on later
> parent MFD driver unbind or LED class callbacks, or resource leaks and
> name clashes on child driver reload).

Shouldn't MFD take reference count for their children?

--
With Best Regards,
Andy Shevchenko