[PATCH AUTOSEL 4.19 8/9] fbdev: lxfb: Fix potential divide by zero

[Sasha Levin]

From: Wei Chen <harperchen1110 at gmail.com>

[ 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 at gmail.com>
Signed-off-by: Helge Deller <deller at gmx.de>
Signed-off-by: Sasha Levin <sashal at 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