Re: [patch] gpiolib: potential oops on failure path

[Linus Walleij <linus.walleij@xxxxxxxxxx>]

On Fri, Jun 17, 2016 at 11:28 AM, walter harms <wharms@xxxxxx> wrote:
> Am 17.06.2016 11:15, schrieb Dan Carpenter:

>>  out_free_descs:
>> +     if (i == GPIOHANDLES_MAX)
>> +             i--;
>>       for (; i >= 0; i--)
>>               gpiod_free(lh->descs[i]);
>>       kfree(lh->label);
>
>
> Since we have already noticed that programmes are bad at counting backwards
> is it possible to change the loop into counting up ?
>
> btw: if lh->descs[i] is initialized to NULL it would be more robust just to free everything like:
>
> for(i=0;i< GPIOHANDLES_MAX; i++)
>   gpiod_free(lh->descs[i]);
>
> just my two cents,

The loop looks like that for a reason: i is indexing upwards while
grabbing the descriptors, then it rewinds that way to free them if
something went wrong during init.

Yours,
Linus Walleij
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