Re: [PATCH] netfilter: ipset: Replace strlcpy with strscpy

From: Kees Cook
Date: Tue Jun 13 2023 - 15:26:45 EST


On Tue, Jun 13, 2023 at 12:34:37AM +0000, Azeem Shaikh wrote:
> strlcpy() reads the entire source buffer first.
> This read may exceed the destination size limit.
> This is both inefficient and can lead to linear read
> overflows if a source string is not NUL-terminated [1].
> In an effort to remove strlcpy() completely [2], replace
> strlcpy() here with strscpy().
>
> Direct replacement is safe here since return value from all
> callers of STRLCPY macro were ignored.

Yeah, the macro name is probably not super helpful here. It seems like
it should have originally be named IFNAME_CPY or something.

>
> [1] https://www.kernel.org/doc/html/latest/process/deprecated.html#strlcpy
> [2] https://github.com/KSPP/linux/issues/89
>
> Signed-off-by: Azeem Shaikh <azeemshaikh38@xxxxxxxxx>

But, regardless:

Reviewed-by: Kees Cook <keescook@xxxxxxxxxxxx>

--
Kees Cook