Re: [PATCH] regulator: Avoid potential NULL dereference in reg_fixed_voltage_probe()

Axel Lin
2011-11-27T12:01:52Z

2011/11/27 Mark Brown <broonie@opensource.wolfsonmicro.com>:
> On Sun, Nov 27, 2011 at 10:13:50AM +0800, Axel Lin wrote:
>
>> -     if (pdev->dev.of_node)
>> +     if (pdev->dev.of_node) {
>>               config = of_get_fixed_voltage_config(&pdev->dev);
>> +             if (!config)
>> +                     return -ENOMEM;
>> +     }
>
> Looking at this I'm thinking it's better to just drop the check for
> of_node entirely and just let of_get_fixed_voltage_config() fail to find
> what it needs.
>
In the case of pdev->dev.of_node == NULL, config points to
pdev->dev.platform_data.

Or do you prefer change it this way:

--- a/drivers/regulator/fixed.c
+++ b/drivers/regulator/fixed.c
@@ -163,12 +163,17 @@ static struct regulator_ops fixed_voltage_ops = {

static int __devinit reg_fixed_voltage_probe(struct platform_device *pdev)
{
- struct fixed_voltage_config *config = pdev->dev.platform_data;
+ struct fixed_voltage_config *config;
struct fixed_voltage_data *drvdata;
int ret;

if (pdev->dev.of_node)
config = of_get_fixed_voltage_config(&pdev->dev);
+ else
+ config = pdev->dev.platform_data;
+
+ if (!config)
+ return -ENOMEM;

drvdata = kzalloc(sizeof(struct fixed_voltage_data), GFP_KERNEL);
if (drvdata == NULL) {