[v8,3/6] power: supply: Add error checking of psy desc during registration

[Heikki Krogerus <heikki.krogerus@linux.intel.com>]

On Mon, Apr 23, 2018 at 03:10:58PM +0100, Adam Thomson wrote:
> Currently there's no error checking of this parameter in the
> registration function and it's blindly added to psy class and
> subsequently used as is. For example if this is NULL the call
> to psy_register_thermal() will try to dereference the pointer
> thus causing a kernel dump.
> 
> This commit updates the registration code to add some basic
> checks on the desc pointer validity, name, and presence of
> properties.
> 
> Signed-off-by: Adam Thomson <Adam.Thomson.Opensource@diasemi.com>

Reviewed-by: Heikki Krogerus <heikki.krogerus@linux.intel.com>

> ---
>  drivers/power/supply/power_supply_core.c | 3 +++
>  1 file changed, 3 insertions(+)
> 
> diff --git a/drivers/power/supply/power_supply_core.c b/drivers/power/supply/power_supply_core.c
> index feac7b0..a7984af 100644
> --- a/drivers/power/supply/power_supply_core.c
> +++ b/drivers/power/supply/power_supply_core.c
> @@ -849,6 +849,9 @@ static void psy_unregister_cooler(struct power_supply *psy)
>  		pr_warn("%s: Expected proper parent device for '%s'\n",
>  			__func__, desc->name);
>  
> +	if (!desc || !desc->name || !desc->properties || !desc->num_properties)
> +		return ERR_PTR(-EINVAL);
> +
>  	psy = kzalloc(sizeof(*psy), GFP_KERNEL);
>  	if (!psy)
>  		return ERR_PTR(-ENOMEM);