fbdev: nvidia: Fix potential divide by zero

[ Upstream commit 92e2a00f2987483e1f9253625828622edd442e61 ]

variable var->pixclock can be set by user. In case it
equals to zero, divide by zero would occur in nvidiafb_set_par.

Similar crashes have happened in other fbdev drivers. There
is no check and modification on var->pixclock along the call
chain to nvidia_check_var and nvidiafb_set_par. We believe it
could also be triggered in driver nvidia from user site.

Signed-off-by: Wei Chen <harperchen1110@gmail.com>
Signed-off-by: Helge Deller <deller@gmx.de>
Signed-off-by: Sasha Levin <sashal@kernel.org>
This commit is contained in:
Wei Chen 2023-03-15 07:18:31 +00:00 committed by Greg Kroah-Hartman
parent f3359f5fc9
commit 868f247e47

View File

@ -766,6 +766,8 @@ static int nvidiafb_check_var(struct fb_var_screeninfo *var,
int pitch, err = 0;
NVTRACE_ENTER();
if (!var->pixclock)
return -EINVAL;
var->transp.offset = 0;
var->transp.length = 0;