RE: [PATCH -next] clk: imx: fix potential NULL dereference in imx8qxp_lpcg_clk_probe()

[Aisheng Dong <aisheng.dong@nxp.com>]

> -----Original Message-----
> From: Wei Yongjun [mailto:weiyongjun1@huawei.com]
> Sent: Tuesday, December 18, 2018 2:43 PM
[...]
> platform_get_resource() may fail and return NULL, so we should better check
> it's return value to avoid a NULL pointer dereference a bit later in the code.
> 
> This is detected by Coccinelle semantic patch.
> 
> @@
> expression pdev, res, n, t, e, e1, e2;
> @@
> 
> res = platform_get_resource(pdev, t, n);
> + if (!res)
> +   return -EINVAL;
> ... when != res == NULL
> e = devm_ioremap(e1, res->start, e2);
> 
> Fixes: 1e3121bfe51a ("clk: imx: add imx8qxp lpcg driver")
> Signed-off-by: Wei Yongjun <weiyongjun1@huawei.com>

Thanks for reporting this.

Reviewed-by: Dong Aisheng <aisheng.dong@nxp.com>

Regards
Dong Aisheng

> ---
>  drivers/clk/imx/clk-imx8qxp-lpcg.c | 2 ++
>  1 file changed, 2 insertions(+)
> 
> diff --git a/drivers/clk/imx/clk-imx8qxp-lpcg.c
> b/drivers/clk/imx/clk-imx8qxp-lpcg.c
> index dcae1dd..8f241a4 100644
> --- a/drivers/clk/imx/clk-imx8qxp-lpcg.c
> +++ b/drivers/clk/imx/clk-imx8qxp-lpcg.c
> @@ -169,6 +169,8 @@ static int imx8qxp_lpcg_clk_probe(struct
> platform_device *pdev)
>  		return -ENODEV;
> 
>  	res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
> +	if (!res)
> +		return -EINVAL;
>  	base = devm_ioremap(dev, res->start, resource_size(res));
>  	if (!base)
>  		return -ENOMEM;
> 
>