Re: [PATCH] i2c: replace deprecated strncpy
From: Kees Cook
Date: Wed Sep 20 2023 - 10:33:17 EST
On Wed, Sep 20, 2023 at 11:07:35AM +0000, Justin Stitt wrote:
> `strncpy` is deprecated for use on NUL-terminated destination strings [1].
>
> We should prefer more robust and less ambiguous string interfaces.
>
> `info.type` is expected to be NUL-terminated judging by its use in
> `i2c_new_client_device()` wherein it is used to populate `client->name`:
> | strscpy(client->name, info->type, sizeof(client->name));
>
> NUL-padding is not required and even if it was, `client` is already
> zero-initialized.
>
> Considering the two points from above, a suitable replacement is
> `strscpy` [2] due to the fact that it guarantees NUL-termination on the
> destination buffer without unnecessarily NUL-padding.
>
> Link: https://www.kernel.org/doc/html/latest/process/deprecated.html#strncpy-on-nul-terminated-strings [1]
> Link: https://manpages.debian.org/testing/linux-manual-4.8/strscpy.9.en.html [2]
> Link: https://github.com/KSPP/linux/issues/90
> Cc: linux-hardening@xxxxxxxxxxxxxxx
> Signed-off-by: Justin Stitt <justinstitt@xxxxxxxxxx>
Looks like a straight replacement. Thanks!
Reviewed-by: Kees Cook <keescook@xxxxxxxxxxxx>
--
Kees Cook