[PATCH] ubifs: replace simple_strtoul() with kstrtoul()

[Geert Uytterhoeven]

Please don't add mindless casts!

On Mon, May 19, 2014 at 5:26 AM, Zhang Zhen <zhenzhang.zhang at huawei.com> wrote:
> --- a/fs/ubifs/super.c
> +++ b/fs/ubifs/super.c
> @@ -1905,6 +1905,7 @@ static struct ubi_volume_desc *open_ubi(const char *name, int mode)
>         struct ubi_volume_desc *ubi;
>         int dev, vol;

dev is int

>         char *endptr;
> +       int ret;
>
>         /* First, try to open using the device node path method */
>         ubi = ubi_open_volume_path(name, mode);
> @@ -1922,7 +1923,10 @@ static struct ubi_volume_desc *open_ubi(const char *name, int mode)
>         if (!isdigit(name[3]))
>                 return ERR_PTR(-EINVAL);
>
> -       dev = simple_strtoul(name + 3, &endptr, 0);
> +       endptr = (char *)name + 3;
> +       ret = kstrtoul(endptr, 0, (unsigned long *)&dev);

On 64-bit, long is 64-bit, hence this will write beyond dev and will corrupt
the stack.

> +       if (ret)
> +               return ERR_PTR(-EINVAL);
>
>         /* ubiY method */
>         if (*endptr == '\0')

Gr{oetje,eeting}s,

                        Geert

--
Geert Uytterhoeven -- There's lots of Linux beyond ia32 -- geert at linux-m68k.org

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