Re: [PATCH] regulator: fixed: Prevent NULL pointer dereference when !CONFIG_OF

[Guenter Roeck]

On Sun, Sep 22, 2019 at 10:29:28AM +0800, Axel Lin wrote:
> Use of_device_get_match_data which has NULL test for match before
> dereference match->data. Add NULL test for drvtype so it still works
> for fixed_voltage_ops when !CONFIG_OF.
> 
> Signed-off-by: Axel Lin <axel.lin@xxxxxxxxxx>
> Reviewed-by: Philippe Schenker <philippe.schenker@xxxxxxxxxxx>

Tested-by: Guenter Roeck <linux@xxxxxxxxxxxx>

> ---
>  drivers/regulator/fixed.c | 5 ++---
>  1 file changed, 2 insertions(+), 3 deletions(-)
> 
> diff --git a/drivers/regulator/fixed.c b/drivers/regulator/fixed.c
> index d90a6fd8cbc7..f81533070058 100644
> --- a/drivers/regulator/fixed.c
> +++ b/drivers/regulator/fixed.c
> @@ -144,8 +144,7 @@ static int reg_fixed_voltage_probe(struct platform_device *pdev)
>  	struct device *dev = &pdev->dev;
>  	struct fixed_voltage_config *config;
>  	struct fixed_voltage_data *drvdata;
> -	const struct fixed_dev_type *drvtype =
> -		of_match_device(dev->driver->of_match_table, dev)->data;
> +	const struct fixed_dev_type *drvtype = of_device_get_match_data(dev);
>  	struct regulator_config cfg = { };
>  	enum gpiod_flags gflags;
>  	int ret;
> @@ -177,7 +176,7 @@ static int reg_fixed_voltage_probe(struct platform_device *pdev)
>  	drvdata->desc.type = REGULATOR_VOLTAGE;
>  	drvdata->desc.owner = THIS_MODULE;
>  
> -	if (drvtype->has_enable_clock) {
> +	if (drvtype && drvtype->has_enable_clock) {
>  		drvdata->desc.ops = &fixed_voltage_clkenabled_ops;
>  
>  		drvdata->enable_clock = devm_clk_get(dev, NULL);