Re: [PATCH] fbdev: fbmon: fix potential divide error in fb_validate_mode

[Date Prev][Date Next][Thread Prev][Thread Next][Date Index][Thread Index]

 



On 10/14/23 14:14, Zhang Shurong wrote:
We can easily use FBIOPUT_VSCREENINFO set fb_var_screeninfo, so
it's possible for a divide by zero error to occur.

Fix this by making sure the divisor is non-zero before the computation.

Signed-off-by: Zhang Shurong <zhang_shurong@xxxxxxxxxxx>
---
  drivers/video/fbdev/core/fbmon.c | 3 +++
  1 file changed, 3 insertions(+)

diff --git a/drivers/video/fbdev/core/fbmon.c b/drivers/video/fbdev/core/fbmon.c
index 79e5bfbdd34c..bdd15b8e3a71 100644
--- a/drivers/video/fbdev/core/fbmon.c
+++ b/drivers/video/fbdev/core/fbmon.c
@@ -1470,6 +1470,9 @@ int fb_validate_mode(const struct fb_var_screeninfo *var, struct fb_info *info)
  	if (var->vmode & FB_VMODE_DOUBLE)
  		vtotal *= 2;

+	if (!htotal || !vtotal)
+		return -EINVAL;

This is above here:
        htotal = var->xres + var->right_margin + var->hsync_len +
                var->left_margin;
        vtotal = var->yres + var->lower_margin + var->vsync_len +
                var->upper_margin;

I don't see how htotal and vtotal can become zero...

Helge




[Index of Archives]     [Linux DRI Users]     [Linux Intel Graphics]     [Linux USB Devel]     [Video for Linux]     [Linux Audio Users]     [Yosemite News]     [Linux Kernel]     [Linux SCSI]     [XFree86]     [Linux USB Devel]     [Video for Linux]     [Linux Audio Users]     [Linux Kernel]     [Linux SCSI]     [XFree86]
  Powered by Linux