diff mbox series

fbdev: nvidia: Fix potential divide by zero

Message ID 20230315071831.3833948-1-harperchen1110@gmail.com
State New
Headers
Series fbdev: nvidia: Fix potential divide by zero |

Commit Message

Wei Chen March 15, 2023, 7:18 a.m. UTC 
  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>
---
 drivers/video/fbdev/nvidia/nvidia.c | 2 ++
 1 file changed, 2 insertions(+)

Comments

Helge Deller March 16, 2023, 1:34 p.m. UTC | #1 
On 3/15/23 08:18, Wei Chen wrote:
> 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>

applied all four patches.

Thanks!
Helge

> ---
>   drivers/video/fbdev/nvidia/nvidia.c | 2 ++
>   1 file changed, 2 insertions(+)
>
> diff --git a/drivers/video/fbdev/nvidia/nvidia.c b/drivers/video/fbdev/nvidia/nvidia.c
> index e60a276b4855..ea4ba3dfb96b 100644
> --- a/drivers/video/fbdev/nvidia/nvidia.c
> +++ b/drivers/video/fbdev/nvidia/nvidia.c
> @@ -764,6 +764,8 @@ 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;
diff mbox series

Patch

diff --git a/drivers/video/fbdev/nvidia/nvidia.c b/drivers/video/fbdev/nvidia/nvidia.c
index e60a276b4855..ea4ba3dfb96b 100644
--- a/drivers/video/fbdev/nvidia/nvidia.c
+++ b/drivers/video/fbdev/nvidia/nvidia.c
@@ -764,6 +764,8 @@  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;