Re: [PATCH v2] scsi: target: Replace deprecated strncpy() with strscpy()

Kees Cook
2025-03-03T18:45:51Z

On Sun, Mar 02, 2025 at 11:56:41PM +0100, Thorsten Blum wrote:
> strncpy() is deprecated for NUL-terminated destination buffers; use
> strscpy() instead. The destination buffer db_root is only used with "%s"
> format strings and must therefore be NUL-terminated, but not NUL-padded.
>
> Use scnprintf() because snprintf() could return a value >= DB_ROOT_LEN
> and lead to an out-of-bounds access. This doesn't happen because count
> is explicitly checked against DB_ROOT_LEN before. However, scnprintf()
> always returns the number of characters actually written to the string
> buffer, which is always within the bounds of db_root_stage, and should
> be preferred over snprintf().
>
> The size parameter of strscpy() is optional and since DB_ROOT_LEN is the
> size of the destination buffer, it can be removed. Remove it to simplify
> the code.
>
> Compile-tested only.
>
> Link: https://github.com/KSPP/linux/issues/90
> Link: https://github.com/KSPP/linux/issues/105
> Cc: linux-hardening@vger.kernel.org
> Signed-off-by: Thorsten Blum <thorsten.blum@linux.dev>

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

--
Kees Cook