[PATCH v2] gpiolib: check validity for gpio_info in *_active()

[Sascha Hauer]

On Thu, Sep 21, 2017 at 10:44:55PM +0200, Uwe Kleine-König wrote:
> gpio_set_active, gpio_is_active and gpio_direction_active are public
> functions, accordingly there should be error checking.
> 
> If an invalid gpio number is given to these functions without checking
> gpio_adjust_value is called with gi == NULL which then dereferences this
> pointer.
> 
> Signed-off-by: Uwe Kleine-König <u.kleine-koenig at pengutronix.de>
> ---
> Changes since (implicit) v1:
> 
>  - make it compile (sigh)

Took this one instead.

Sascha

> 
>  drivers/gpio/gpiolib.c | 12 ++++++++++++
>  1 file changed, 12 insertions(+)
> 
> diff --git a/drivers/gpio/gpiolib.c b/drivers/gpio/gpiolib.c
> index 67d771bae3a8..b83a27de7d21 100644
> --- a/drivers/gpio/gpiolib.c
> +++ b/drivers/gpio/gpiolib.c
> @@ -204,6 +204,10 @@ EXPORT_SYMBOL(gpio_set_value);
>  void gpio_set_active(unsigned gpio, bool value)
>  {
>  	struct gpio_info *gi = gpio_to_desc(gpio);
> +
> +	if (!gi)
> +		return;
> +
>  	gpio_set_value(gpio, gpio_adjust_value(gi, value));
>  }
>  EXPORT_SYMBOL(gpio_set_active);
> @@ -229,6 +233,10 @@ EXPORT_SYMBOL(gpio_get_value);
>  int gpio_is_active(unsigned gpio)
>  {
>  	struct gpio_info *gi = gpio_to_desc(gpio);
> +
> +	if (!gi)
> +		return -ENODEV;
> +
>  	return gpio_adjust_value(gi, gpio_get_value(gpio));
>  }
>  EXPORT_SYMBOL(gpio_is_active);
> @@ -255,6 +263,10 @@ EXPORT_SYMBOL(gpio_direction_output);
>  int gpio_direction_active(unsigned gpio, bool value)
>  {
>  	struct gpio_info *gi = gpio_to_desc(gpio);
> +
> +	if (!gi)
> +		return -ENODEV;
> +
>  	return gpio_direction_output(gpio, gpio_adjust_value(gi, value));
>  }
>  EXPORT_SYMBOL(gpio_direction_active);
> -- 
> 2.11.0
> 
> 
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