2023-03-15 08:34:08

by Wei Chen

[permalink] [raw]
Subject: [PATCH] fbdev: intelfb: Fix potential divide by zero

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 <[email protected]>
---
drivers/video/fbdev/intelfb/intelfbdrv.c | 3 +++
1 file changed, 3 insertions(+)

diff --git a/drivers/video/fbdev/intelfb/intelfbdrv.c b/drivers/video/fbdev/intelfb/intelfbdrv.c
index 0a9e5067b201..a81095b2b1ea 100644
--- a/drivers/video/fbdev/intelfb/intelfbdrv.c
+++ b/drivers/video/fbdev/intelfb/intelfbdrv.c
@@ -1222,6 +1222,9 @@ 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;
--
2.25.1