Re: [PATCH 2/2] pinctrl: renesas: rzn1: fix possible null-ptr-deref in sh_pfc_map_resources()

[Geert Uytterhoeven]

Hi Yang,

On Fri, Apr 29, 2022 at 1:22 PM Yang Yingliang <yangyingliang@xxxxxxxxxx> wrote:
> It will cause null-ptr-deref when using 'res', if platform_get_resource()
> returns NULL, so move using 'res' after devm_ioremap_resource() that
> will check it to avoid null-ptr-deref.
> And use devm_platform_get_and_ioremap_resource() to simplify code.
>
> Signed-off-by: Yang Yingliang <yangyingliang@xxxxxxxxxx>

Thanks for your patch!

> --- a/drivers/pinctrl/renesas/pinctrl-rzn1.c
> +++ b/drivers/pinctrl/renesas/pinctrl-rzn1.c
> @@ -865,17 +865,15 @@ static int rzn1_pinctrl_probe(struct platform_device *pdev)
>         ipctl->mdio_func[0] = -1;
>         ipctl->mdio_func[1] = -1;
>
> -       res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
> -       ipctl->lev1_protect_phys = (u32)res->start + 0x400;
> -       ipctl->lev1 = devm_ioremap_resource(&pdev->dev, res);
> +       ipctl->lev1 = devm_platform_get_and_ioremap_resource(pdev, 0, &res);
>         if (IS_ERR(ipctl->lev1))
>                 return PTR_ERR(ipctl->lev1);
> +       ipctl->lev1_protect_phys = (u32)res->start + 0x400;
>
> -       res = platform_get_resource(pdev, IORESOURCE_MEM, 1);
> -       ipctl->lev2_protect_phys = (u32)res->start + 0x400;
> -       ipctl->lev2 = devm_ioremap_resource(&pdev->dev, res);
> +       ipctl->lev2 = devm_platform_get_and_ioremap_resource(pdev, 0, &res);

..., 1, ...

>         if (IS_ERR(ipctl->lev2))
>                 return PTR_ERR(ipctl->lev2);
> +       ipctl->lev2_protect_phys = (u32)res->start + 0x400;
>
>         ipctl->clk = devm_clk_get(&pdev->dev, NULL);
>         if (IS_ERR(ipctl->clk))

Reviewed-by: Geert Uytterhoeven <geert+renesas@xxxxxxxxx>
i.e. will queue in renesas-pinctrl-for-v5.19, with the above fixed
(no need to resend).

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