Re: [PATCH net-next] net/rds: Replace deprecated strncpy() with strscpy_pad()

Kees Cook
2025-02-20T08:54:42Z

On February 19, 2025 11:04:18 PM PST, Thorsten Blum <thorsten.blum@linux.dev> wrote:
>On 20. Feb 2025, at 03:57, Kees Cook wrote:
>> On Wed, Feb 19, 2025 at 11:47:31PM +0100, Thorsten Blum wrote:
>>> strncpy() is deprecated for NUL-terminated destination buffers. Use
>>> strscpy_pad() instead and remove the manual NUL-termination.
>>
>> When doing these conversions, please describe two aspects of
>> conversions:
>>
>> - Why is it safe to be NUL terminated
>> - Why is it safe to be/not-be NUL-padded
>>
>> In this case, the latter needs examination. Looking at how ctr is used,
>> it is memcpy()ed later, which means this string MUST be NUL padded or it
>> will leak stack memory contents.
>>
>> So, please use strscpy_pad() here. :)
>
>I am using strscpy_pad() here already because of the NUL-padding.
>
>Did you just miss that?

Well that's embarrassing. Yes, I must need stronger glasses. *sigh* Apologies for the noise!

Reviewed-by: Kees Cook <kees@kernel.org>

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Kees Cook