# Re: \[PATCH\] vgacon, x86/boot: Prevent faulty bootparams.screeninfo from causing harm

- From: Jan H. Schönherr \<hidden\>
- Date: 2017-08-27 16:47:49 
- List: linux-fbdev
- Page: https://ratatoskr.run/linux-fbdev/2017/08/13466739
- Thread: https://ratatoskr.run/linux-fbdev/2017/08/13466737/t.md

```text
On 08/27/2017 05:05 PM, Greg Kroah-Hartman wrote:
> On Sun, Aug 27, 2017 at 03:56:46PM +0200, Jan H. Schönherr wrote:
>> If a zero for the number of colums or rows manages to slip through,
>> gotoxy() will underflow vc->vc_pos, causing the next action on the
>> referenced memory to end with a page fault.
>>
>> Make the check in vgacon more pessimistic to prevent that. Also change
>> a similar check in the x86 boot code with a similar problem.
>>
>> Signed-off-by: Jan H. Schönherr <redacted>
>> ---
>> Let me know, if I should split this into two patches.
>>
>>  arch/x86/boot/compressed/misc.c | 3 +--
>>  drivers/video/console/vgacon.c  | 5 ++---
>>  2 files changed, 3 insertions(+), 5 deletions(-)
>
> Why send this patch to me?

Because there isn't a clear maintainer: The drivers/video catch-all in MAINTAINERS
is captioned as "Framebuffer layer",  but all recent patches to vgacon.c went through
your hands.

> And yes, of course you have to split this up, these two files have
> nothing to do with each other...

Okay, then ignore this patch, and I'll split this down. I'll send the vgacon.c part
through Bartlomiej Zolnierkiewicz, then.

Regards
Jan

```