Re: [PATCH 03/10] scsi: NCR5380: Replace snprintf() with the safer scnprintf() variant

Kees Cook
2024-02-10T07:14:02Z

On Thu, Feb 08, 2024 at 08:44:15AM +0000, Lee Jones wrote:
> There is a general misunderstanding amongst engineers that {v}snprintf()
> returns the length of the data *actually* encoded into the destination
> array. However, as per the C99 standard {v}snprintf() really returns
> the length of the data that *would have been* written if there were
> enough space for it. This misunderstanding has led to buffer-overruns
> in the past. It's generally considered safer to use the {v}scnprintf()
> variants in their place (or even sprintf() in simple cases). So let's
> do that.
>
> Link: https://lwn.net/Articles/69419/
> Link: https://github.com/KSPP/linux/issues/105
> Signed-off-by: Lee Jones <lee@kernel.org>

Reviewed-by: Kees Cook <keescook@chromium.org>

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Kees Cook