Re: [PATCH] video: fbdev: sis: Error out if pixclock equals zero

From: Helge Deller
Date: Sun Jan 21 2024 - 03:02:25 EST


On 1/18/24 07:24, Fullway Wang wrote:
The userspace program could pass any values to the driver through
ioctl() interface. If the driver doesn't check the value of pixclock,
it may cause divide-by-zero error.

In sisfb_check_var(), var->pixclock is used as a divisor to caculate
drate before it is checked against zero. Fix this by checking it
at the beginning.

This is similar to CVE-2022-3061 in i740fb which was fixed by
commit 15cf0b8.

Signed-off-by: Fullway Wang <fullwaywang@xxxxxxxxxxx>
---
drivers/video/fbdev/sis/sis_main.c | 2 ++
1 file changed, 2 insertions(+)

I've applied this patch and your savage patch to fbdev git tree.

Thanks!
Helge