# Re: \[PATCH net 3/4\] net: dsa: microchip: Utilize strncpy() for ethtool::get\_strings

- From: Florian Fainelli \<f.fainelli@gmail.com\>
- Date: 2018-03-02 18:25:15 
- List: netdev
- Page: https://ratatoskr.run/netdev/2018/03/5229870
- Thread: https://ratatoskr.run/netdev/2018/03/5229251/t.md

```text
On 03/02/2018 02:51 AM, David Laight wrote:
> From: Florian Fainelli
>>
>> Do not use memcpy() which is not safe, but instead use strncpy() which
>> will make sure that the string is NUL terminated (in the Linux
>> implementation) if the string is smaller than the length specified. This
>> fixes KASAN out of bounds warnings while fetching port statistics.
> 
> You really ought to use a copy function that will truncate the
> string if it is too long.
> Just assuming the string isn't too long is asking for trouble.
> You might (almost) just use strcpy().
> 
> strlcpy() will probably work best here.

Right, or if we actually do size the statistics string to be
ETH_GSTRING_LEN bytes, memcpy() can be used, provided that the strings
are initialized correctly (which they are).
-- 
Florian
```