Re: [PATCH 1/2] gpio: sim: dispose of irq mappings before destroying the irq_sim domain

[Andy Shevchenko <andriy.shevchenko@xxxxxxxxxxxxxxx>]

On Tue, Aug 22, 2023 at 09:51:21AM +0200, Bartosz Golaszewski wrote:
> From: Bartosz Golaszewski <bartosz.golaszewski@xxxxxxxxxx>
> 
> If a GPIO simulator device is unbound with interrupts still requested,
> we will hit a use-after-free issue in __irq_domain_deactivate_irq(). The
> owner of the irq domain must dispose of all mappings before destroying
> the domain object.

...

> +static void gpio_sim_dispose_mappings(void *data)
> +{
> +	struct gpio_sim_chip *chip = data;
> +	unsigned int i, irq;
> +
> +	for (i = 0; i < chip->gc.ngpio; i++) {
> +		irq = irq_find_mapping(chip->irq_sim, i);

> +		if (irq)

This duplicates check in the following call.

> +			irq_dispose_mapping(irq);
> +	}
> +}

-- 
With Best Regards,
Andy Shevchenko