Re: [PATCH] gpio: mvebu: validate ngpios before use

[Rosen Penev]

On Wed, Jul 8, 2026 at 5:06 AM Bartosz Golaszewski <brgl@xxxxxxxxxx> wrote:
>
> On Wed, 8 Jul 2026 01:27:42 +0200, Rosen Penev <rosenp@xxxxxxxxx> said:
> > If ngpios is read as 0 from device tree, it is passed via
> > irq_alloc_domain_generic_chips() as irqs_per_chip, which leads to a
> > division by zero in DIV_ROUND_UP(d->revmap_size, irqs_per_chip).
> > Reject ngpios == 0 early.
> >
> > Fixes: fefe7b0923459 ("gpio: introduce gpio-mvebu driver for Marvell SoCs")
> > Assisted-by: opencode:big-pickle
> > Signed-off-by: Rosen Penev <rosenp@xxxxxxxxx>
> > ---
> >  drivers/gpio/gpio-mvebu.c | 5 +++++
> >  1 file changed, 5 insertions(+)
> >
> > diff --git a/drivers/gpio/gpio-mvebu.c b/drivers/gpio/gpio-mvebu.c
> > index 39c1a13e1b65..c7cbfbfb4800 100644
> > --- a/drivers/gpio/gpio-mvebu.c
> > +++ b/drivers/gpio/gpio-mvebu.c
> > @@ -1175,6 +1175,11 @@ static int mvebu_gpio_probe(struct platform_device *pdev)
> >               return -ENODEV;
> >       }
> >
> > +     if (!ngpios) {
> > +             dev_err(&pdev->dev, "ngpios must be greater than 0\n");
Sashiko suggests upper limit bound as well.
>
> return dev_err_probe()?
surrounding code doesn't use it. dev_err_probe is mostly useful with
variable error codes anyway.
>
> > +             return -EINVAL;
> > +     }
> > +
> >       id = of_alias_get_id(pdev->dev.of_node, "gpio");
> >       if (id < 0) {
> >               dev_err(&pdev->dev, "Couldn't get OF id\n");
> > --
> > 2.55.0
> >
> >