[PATCH AUTOSEL 4.14 8/9] fbdev: lxfb: Fix potential divide by zero

Sasha Levin
2023-03-22T20:33:57Z

[ Upstream commit 61ac4b86a4c047c20d5cb423ddd87496f14d9868 ]

var->pixclock can be assigned to zero by user. Without proper
check, divide by zero would occur in lx_set_clock.

Error out if var->pixclock is zero.

Signed-off-by: Wei Chen <harperchen1110@gmail.com>
Signed-off-by: Helge Deller <deller@gmx.de>
Signed-off-by: Sasha Levin <sashal@kernel.org>
---
drivers/video/fbdev/geode/lxfb_core.c | 3 +++
1 file changed, 3 insertions(+)

diff --git a/drivers/video/fbdev/geode/lxfb_core.c b/drivers/video/fbdev/geode/lxfb_core.c
index 138da6cb6cbcd..4345246b4c798 100644
--- a/drivers/video/fbdev/geode/lxfb_core.c
+++ b/drivers/video/fbdev/geode/lxfb_core.c
@@ -247,6 +247,9 @@ static void get_modedb(struct fb_videomode **modedb, unsigned int *size)

static int lxfb_check_var(struct fb_var_screeninfo *var, struct fb_info *info)
{
+ if (!var->pixclock)
+ return -EINVAL;
+
if (var->xres > 1920 || var->yres > 1440)
return -EINVAL;

--
2.39.2