[lvc-project] [PATCH] drm/nouveau/clk: prevent division by zero in gt215_clk_info()

[Fedor Pchelkin]

On Mon, 30. Sep 18:25, Igor Artemiev wrote:
> sdiv can be zero if read_vco() returns 0 or khz is greater than sclk*2.
> This value will cause a division-by-zero error in the gt215_clk_info() function.
> 
> Add a check before division. 
> 
> Found by Linux Verification Center (linuxtesting.org) with static
> analysis tool SVACE.
> 
> Signed-off-by: Igor Artemiev <Igor.A.Artemiev at mcst.ru>
> ---

Патч добавлен в LVC-5.10 и 6.1. Спасибо!

>  drivers/gpu/drm/nouveau/nvkm/subdev/clk/gt215.c | 3 +++
>  1 file changed, 3 insertions(+)
> 
> diff --git a/drivers/gpu/drm/nouveau/nvkm/subdev/clk/gt215.c b/drivers/gpu/drm/nouveau/nvkm/subdev/clk/gt215.c
> index b5f3969727a2..4c53442b4167 100644
> --- a/drivers/gpu/drm/nouveau/nvkm/subdev/clk/gt215.c
> +++ b/drivers/gpu/drm/nouveau/nvkm/subdev/clk/gt215.c
> @@ -206,6 +206,9 @@ gt215_clk_info(struct nvkm_clk *base, int idx, u32 khz,
>  	default:
>  		sclk = read_vco(clk, idx);
>  		sdiv = min((sclk * 2) / khz, (u32)65);
> +		if (!sdiv)
> +			return -EINVAL;
> +
>  		oclk = (sclk * 2) / sdiv;
>  		diff = ((khz + 3000) - oclk);
>  
> -- 
> 2.39.2