Re: [PATCH 2/2] gpiolib: cdev: release IRQs when the gpio chip device is removed

[Kent Gibson <warthog618@xxxxxxxxx>]

On Wed, Feb 21, 2024 at 08:25:55AM +0800, Kent Gibson wrote:
> On Tue, Feb 20, 2024 at 07:26:57PM +0100, Herve Codina wrote:
> > Hi Kent,
> >
> >
> > I probably missed something but I don't see this use after free.
> > Can you give me some details/pointers ?
> >
>
> What is to prevent userspace releasing the request and freeing the
> linereq while you use it?  The use after free is anywhere that is
> possible.
>

To answer my own question - the notifier call chain itself will prevent
that - linereq_free() will get blocked on the notifier chain semaphore
until the notifier call returns. So there is no use after free problem.

My bad - sorry for the added confusion.

Cheers,
Kent.