Re: [syzbot] BUG: unable to handle kernel paging request in vga16fb_fillrect

[Geert Uytterhoeven]

Hi Tetsuo,

On Mon, Aug 30, 2021 at 4:38 PM Tetsuo Handa
<penguin-kernel@xxxxxxxxxxxxxxxxxxx> wrote:
> On 2021/08/30 23:30, Geert Uytterhoeven wrote:
> > The highest possible value of maxmem inside vga16fb_check_var()
> > is 65536.
>
> Yes.
>
> >
> > So I believe
> >
> >     if (array_size(vxres, vyres) > maxmem)
> >
> > should work fine.
>
> My intent is to check at common path than individual module so that we don't
> need to add same check to every module. Same approach is proposed at
> https://lkml.kernel.org/r/1630294223-7225-1-git-send-email-tcs_kernel@xxxxxxxxxxx .

Which I believe is wrong.
Thanks for the pointer, I will reply to the actual patch...

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