Re: [PATCH] atmel: using strlcpy() to avoid possible buffer overflows
From: Andy Shevchenko
Date: Fri Jun 29 2018 - 17:51:56 EST
On Sat, Jun 30, 2018 at 12:47 AM, Andy Shevchenko
<andy.shevchenko@xxxxxxxxx> wrote:
> On Fri, Jun 29, 2018 at 5:51 AM, YueHaibing <yuehaibing@xxxxxxxxxx> wrote:
>> 'firmware' is a module param which may been longer than firmware_id,
>> so using strlcpy() to guard against overflows
>
> strncat() is against overflow, this does a bit more.
>
>> priv->firmware_id[0] = '\0';
> ...
>> if (firmware) /* module parameter */
>> - strcpy(priv->firmware_id, firmware);
>> + strlcpy(priv->firmware_id, firmware, sizeof(priv->firmware_id));
>
> In either case the above '\0' is not needed.
> But it looks like the intention was to use strncat() / strlcat().
Ah, this is under condition, yes. If no parameter supplied, this needs
to be clean, but
priv is allocated with zeroed memory
https://elixir.bootlin.com/linux/latest/source/net/core/dev.c#L8369
--
With Best Regards,
Andy Shevchenko