This is a note to let you know that I've just added the patch titled
fbdev: intelfb: Fix potential divide by zero
to the 4.19-stable tree which can be found at:
http://www.kernel.org/git/?p=linux/kernel/git/stable/stable-queue.git;a=summary
The filename of the patch is:
fbdev-intelfb-fix-potential-divide-by-zero.patch
and it can be found in the queue-4.19 subdirectory.
If you, or anyone else, feels it should not be added to the stable tree,
please let <stable@xxxxxxxxxxxxxxx> know about it.
commit 0e12b2ea6cc9970048541a9a4863711873db1b06
Author: Wei Chen <harperchen1110@xxxxxxxxx>
Date: Wed Mar 15 08:33:47 2023 +0000
fbdev: intelfb: Fix potential divide by zero
[ Upstream commit d823685486a3446d061fed7c7d2f80af984f119a ]
Variable var->pixclock is controlled by user and can be assigned
to zero. Without proper check, divide by zero would occur in
intelfbhw_validate_mode and intelfbhw_mode_to_hw.
Error out if var->pixclock is zero.
Signed-off-by: Wei Chen <harperchen1110@xxxxxxxxx>
Signed-off-by: Helge Deller <deller@xxxxxx>
Signed-off-by: Sasha Levin <sashal@xxxxxxxxxx>
diff --git a/drivers/video/fbdev/intelfb/intelfbdrv.c b/drivers/video/fbdev/intelfb/intelfbdrv.c
index d7463a2a5d83f..c97c0c8514809 100644
--- a/drivers/video/fbdev/intelfb/intelfbdrv.c
+++ b/drivers/video/fbdev/intelfb/intelfbdrv.c
@@ -1215,6 +1215,9 @@ static int intelfb_check_var(struct fb_var_screeninfo *var,
dinfo = GET_DINFO(info);
+ if (!var->pixclock)
+ return -EINVAL;
+
/* update the pitch */
if (intelfbhw_validate_mode(dinfo, var) != 0)
return -EINVAL;
