[PATCH -next] soc: imx: gpc: add check for of_match_device in imx_gpc_old_dt_init

[PATCH -next] soc: imx: gpc: add check for of_match_device in imx_gpc_old_dt_init

[Tong Tiangen]

Add check for of_match_device in imx_gpc_old_dt_init to avoid potential
NULL dereference of of_id.

Signed-off-by: Tong Tiangen <tongtiangen@huawei.com>
---
 drivers/soc/imx/gpc.c | 17 ++++++++++++++---
 1 file changed, 14 insertions(+), 3 deletions(-)

diff --git a/drivers/soc/imx/gpc.c b/drivers/soc/imx/gpc.c
index 90a8b2c0676f..017a5e2bd4e6 100644
--- a/drivers/soc/imx/gpc.c
+++ b/drivers/soc/imx/gpc.c
@@ -403,14 +403,25 @@ static int imx_gpc_old_dt_init(struct device *dev, struct regmap *regmap,
 
 static int imx_gpc_probe(struct platform_device *pdev)
 {
-	const struct of_device_id *of_id =
-			of_match_device(imx_gpc_dt_ids, &pdev->dev);
-	const struct imx_gpc_dt_data *of_id_data = of_id->data;
+	const struct of_device_id *of_id;
+	const struct imx_gpc_dt_data *of_id_data;
 	struct device_node *pgc_node;
 	struct regmap *regmap;
 	void __iomem *base;
 	int ret;
 
+	of_id = of_match_device(imx_gpc_dt_ids, &pdev->dev);
+	if (!of_id) {
+		dev_err(&pdev->dev, "OF id missing\n");
+		return -EINVAL;
+	}
+
+	of_id_data = of_id->data;
+	if (!of_id_data) {
+		dev_err(&pdev->dev, "OF id data missing\n");
+		return -EINVAL;
+	}
+
 	pgc_node = of_get_child_by_name(pdev->dev.of_node, "pgc");
 
 	/* bail out if DT too old and doesn't provide the necessary info */
-- 
2.18.0.huawei.25

RE: [PATCH -next] soc: imx: gpc: add check for of_match_device in imx_gpc_old_dt_init

[Jacky Bai]

> Subject: [PATCH -next] soc: imx: gpc: add check for of_match_device in
> imx_gpc_old_dt_init
> 
> Add check for of_match_device in imx_gpc_old_dt_init to avoid potential
> NULL dereference of of_id.
> 
> Signed-off-by: Tong Tiangen <tongtiangen@huawei.com>
> ---
>  drivers/soc/imx/gpc.c | 17 ++++++++++++++---
>  1 file changed, 14 insertions(+), 3 deletions(-)
> 
> diff --git a/drivers/soc/imx/gpc.c b/drivers/soc/imx/gpc.c index
> 90a8b2c0676f..017a5e2bd4e6 100644
> --- a/drivers/soc/imx/gpc.c
> +++ b/drivers/soc/imx/gpc.c
> @@ -403,14 +403,25 @@ static int imx_gpc_old_dt_init(struct device *dev,
> struct regmap *regmap,
> 
>  static int imx_gpc_probe(struct platform_device *pdev)  {
> -	const struct of_device_id *of_id =
> -			of_match_device(imx_gpc_dt_ids, &pdev->dev);
> -	const struct imx_gpc_dt_data *of_id_data = of_id->data;
> +	const struct of_device_id *of_id;
> +	const struct imx_gpc_dt_data *of_id_data;
>  	struct device_node *pgc_node;
>  	struct regmap *regmap;
>  	void __iomem *base;
>  	int ret;
> 
> +	of_id = of_match_device(imx_gpc_dt_ids, &pdev->dev);
> +	if (!of_id) {
> +		dev_err(&pdev->dev, "OF id missing\n");
> +		return -EINVAL;
> +	}
> +
> +	of_id_data = of_id->data;
> +	if (!of_id_data) {
> +		dev_err(&pdev->dev, "OF id data missing\n");
> +		return -EINVAL;
> +	}
> +

I think there is no chance to pass 'invalid of_id' and 'of_id_data' to the probe function.
Such check seems not really necessary.

BR
Jacky Bai

>  	pgc_node = of_get_child_by_name(pdev->dev.of_node, "pgc");
> 
>  	/* bail out if DT too old and doesn't provide the necessary info */
> --
> 2.18.0.huawei.25

Re: [PATCH -next] soc: imx: gpc: add check for of_match_device in imx_gpc_old_dt_init

[Fabio Estevam]

On Tue, Jun 1, 2021 at 7:11 AM Jacky Bai <ping.bai@nxp.com> wrote:

> I think there is no chance to pass 'invalid of_id' and 'of_id_data' to the probe function.
> Such check seems not really necessary.

I agree. The only way this driver can probe is via device tree.

Re: [PATCH -next] soc: imx: gpc: add check for of_match_device in imx_gpc_old_dt_init

[tongtiangen]

On 2021/6/1 22:04, Fabio Estevam wrote:
> On Tue, Jun 1, 2021 at 7:11 AM Jacky Bai <ping.bai@nxp.com> wrote:
>
>> I think there is no chance to pass 'invalid of_id' and 'of_id_data' to the probe function.
>> Such check seems not really necessary.
> I agree. The only way this driver can probe is via device tree.
> .
ok,  there is no problem in practical use.   thanks all.
>