Re: [PATCH] video: fbdev: vga16fb: fix OOB write in vga16fb_imageblit()

[Linus Torvalds]

On Fri, May 14, 2021 at 9:20 AM Tetsuo Handa
<penguin-kernel@xxxxxxxxxxxxxxxxxxx> wrote:
>
> Currently it is impossible to control upper limit of rows/columns values
> based on amount of memory reserved for the graphical screen, for
> resize_screen() calls vc->vc_sw->con_resize() only if vc->vc_mode is not
> already KD_GRAPHICS

Honestly, the saner approach would seem to be to simply error out if
vc_mode is KD_GRAPHICS.

Doing VT_RESIZE while in KD_GRAPHICS mode seems _very_ questionable,
and is clearly currently very buggy.

So why not just say "that clearly already doesn't work, so make it
explicitly not permitted"?

              Linus