Re: [PATCH 05/10] gpio: mockup: improve the debugfs input sanitization

From: Bartosz Golaszewski
Date: Mon May 29 2017 - 02:57:27 EST


2017-05-27 18:47 GMT+02:00 Andy Shevchenko <andy.shevchenko@xxxxxxxxx>:
> On Sat, May 27, 2017 at 7:45 PM, Andy Shevchenko
> <andy.shevchenko@xxxxxxxxx> wrote:
>> On Thu, May 25, 2017 at 11:33 AM, Bartosz Golaszewski <brgl@xxxxxxxx> wrote:
>>> We're currently only checking the first character of the input to the
>>> debugfs event files, so a string like '0sdfdsf' is valid and indicates
>>> a falling edge event.
>>>
>>> Be more strict and only allow '0', '1', '0\n' & '1\n'.
>>
>> Why not to be so strict and use
>>
>> kstrtobool_from_user();
>>
>> instead?
>

Because it doesn't really make sense here - we're indicating a RISING
or FALLING edge event. This doesn't really correspond well with
boolean values IMO.

> Or if you still wish to be strict,
> ret = kstrtou8_from_user();
> if (ret)
> return ret;
>
> if (val > 1)
> return -ERANGE;
>
> or alike.

This one looks good, I'll include it in v2.

Thanks,
Bartosz