Messages in this thread | | | Date | Mon, 16 Oct 2023 23:15:28 +0200 | Subject | Re: [PATCH] fbdev: fbmon: fix potential divide error in fb_validate_mode | From | Helge Deller <> |
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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@foxmail.com> > --- > 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
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