Re: [PATCH 1/1] irqchip/renesas-irqc: fix generic IRQ chip leak on remove

[Geert Uytterhoeven]

Hi Qingshuang,

On Fri, 12 Jun 2026 at 08:55, <fffsqian@xxxxxxx> wrote:
> From: Qingshuang Fu <fuqingshuang@xxxxxxxxxx>
>
> The driver allocates domain generic chips using
> irq_alloc_domain_generic_chips() during probe. However, on driver
> remove, the generic chips are not automatically freed when the IRQ
> domain is removed because the domain flags do not include
> IRQ_DOMAIN_FLAG_DESTROY_GC.
>
> This causes both the domain generic chips structure and the associated
> generic chips to be leaked. Additionally, the generic chips remain on
> the global gc_list and may later be visited by generic IRQ chip suspend,
> resume, or shutdown callbacks after the driver has been removed,
> potentially resulting in a use-after-free and kernel crash.
>
> Fix the resource leak by explicitly calling
> irq_domain_remove_generic_chips() before removing the IRQ domain in
> both irqc_remove() and the probe error path.

Thanks for your patch!

>
> Fixes: 17c888920949 ("irqchip/renesas-irqc: Use proper irq_chip name and parent")

Shouldn't that be

Fixes: 99c221df33fbfa1b ("irqchip/renesas-irqc: Move over to nested
generic chip")

?

> Signed-off-by: Qingshuang Fu <fuqingshuang@xxxxxxxxxx>

> --- a/drivers/irqchip/irq-renesas-irqc.c
> +++ b/drivers/irqchip/irq-renesas-irqc.c
> @@ -211,6 +211,7 @@ static int irqc_probe(struct platform_device *pdev)
>         return 0;
>
>  err_remove_domain:
> +       irq_domain_remove_generic_chips(p->irq_domain);

While I had expected a new label, this is indeed not needed, as
irq_domain_remove_generic_chips() is a no-op if irq_domain.gc
is NULL, which is the case if irq_domain_alloc_generic_chips() fails.

>         irq_domain_remove(p->irq_domain);
>  err_runtime_pm_disable:
>         pm_runtime_put(dev);

Reviewed-by: Geert Uytterhoeven <geert+renesas@xxxxxxxxx>

Gr{oetje,eeting}s,

                        Geert

-- 
Geert Uytterhoeven -- There's lots of Linux beyond ia32 -- geert@xxxxxxxxxxxxxx

In personal conversations with technical people, I call myself a hacker. But
when I'm talking to journalists I just say "programmer" or something like that.
                                -- Linus Torvalds