Re: [PATCH] fbdev: controlfb: Add missing modes to fix out of bounds access

From: Bartlomiej Zolnierkiewicz
Date: Thu Nov 09 2017 - 11:11:54 EST


On Tuesday, November 07, 2017 03:05:05 PM Geert Uytterhoeven wrote:
> Dan's static analysis says:
>
> drivers/video/fbdev/controlfb.c:560 control_setup()
> error: buffer overflow 'control_mac_modes' 20 <= 21
>
> Indeed, control_mac_modes[] has only 20 elements, while VMODE_MAX is 22,
> which may lead to an out of bounds read when parsing vmode commandline
> options.
>
> The bug was introduced in v2.4.5.6, when 2 new modes were added to
> macmodes.h, but control_mac_modes[] wasn't updated:
>
> https://kernel.opensuse.org/cgit/kernel/diff/include/video/macmodes.h?h=v2.5.2&id=29f279c764808560eaceb88fef36cbc35c529aad
>
> Augment control_mac_modes[] with the two new video modes to fix this.
>
> Reported-by: Dan Carpenter <dan.carpenter@xxxxxxxxxx>
> Signed-off-by: Geert Uytterhoeven <geert@xxxxxxxxxxxxxx>

Patch queued for 4.15, thanks.

Best regards,
--
Bartlomiej Zolnierkiewicz
Samsung R&D Institute Poland
Samsung Electronics