[lvc-project] [PATCH] gpio: davinci: Validate the obtained number of IRQs

[Bartosz Golaszewski]

On Tue, Jun 18, 2024 at 4:45 PM Aleksandr Mishin <amishin at t-argos.ru> wrote:
>
> Value of pdata->gpio_unbanked is taken from Device Tree. In case of broken
> DT due to any error this value can be any. Without this value validation
> there can be out of chips->irqs array boundaries access in
> davinci_gpio_probe().
>
> Validate the obtained nirq value so that it won't exceed the maximum
> number of IRQs per bank.
>
> Found by Linux Verification Center (linuxtesting.org) with SVACE.
>

Why not Reported-by: ?

Bart

> Fixes: eb3744a2dd01 ("gpio: davinci: Do not assume continuous IRQ numbering")
> Signed-off-by: Aleksandr Mishin <amishin at t-argos.ru>
> ---
>  drivers/gpio/gpio-davinci.c | 5 +++++
>  1 file changed, 5 insertions(+)
>
> diff --git a/drivers/gpio/gpio-davinci.c b/drivers/gpio/gpio-davinci.c
> index bb499e362912..1d0175d6350b 100644
> --- a/drivers/gpio/gpio-davinci.c
> +++ b/drivers/gpio/gpio-davinci.c
> @@ -225,6 +225,11 @@ static int davinci_gpio_probe(struct platform_device *pdev)
>         else
>                 nirq = DIV_ROUND_UP(ngpio, 16);
>
> +       if (nirq > MAX_INT_PER_BANK) {
> +               dev_err(dev, "Too many IRQs!\n");
> +               return -EINVAL;
> +       }
> +
>         chips = devm_kzalloc(dev, sizeof(*chips), GFP_KERNEL);
>         if (!chips)
>                 return -ENOMEM;
> --
> 2.30.2
>