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

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Date:   Sat, 27 May 2017 19:47:46 +0300
From:   Andy Shevchenko <andy.shevchenko@...il.com>
To:     Bartosz Golaszewski <brgl@...ev.pl>
Cc:     Linus Walleij <linus.walleij@...aro.org>,
        Alexandre Courbot <gnurou@...il.com>,
        Bamvor Jian Zhang <bamvor.zhangjian@...aro.org>,
        "linux-gpio@...r.kernel.org" <linux-gpio@...r.kernel.org>,
        "linux-kernel@...r.kernel.org" <linux-kernel@...r.kernel.org>
Subject: Re: [PATCH 05/10] gpio: mockup: improve the debugfs input sanitization

On Sat, May 27, 2017 at 7:45 PM, Andy Shevchenko
<andy.shevchenko@...il.com> wrote:
> On Thu, May 25, 2017 at 11:33 AM, Bartosz Golaszewski <brgl@...ev.pl> 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?

Or if you still wish to be strict,
ret = kstrtou8_from_user();
if (ret)
 return ret;

if (val > 1)
 return -ERANGE;

or alike.

-- 
With Best Regards,
Andy Shevchenko