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

From: Guenter Roeck
Date: Mon Oct 07 2019 - 10:24:22 EST


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);