Re: [PATCH] ionic: replace deprecated strncpy with strscpy

Nelson, Shannon
2023-10-11T22:17:18Z

On 10/11/2023 2:53 PM, 'Justin Stitt' via Pensando Drivers wrote:
>
> strncpy() is deprecated for use on NUL-terminated destination strings
> [1] and as such we should prefer more robust and less ambiguous string
> interfaces.
>
> NUL-padding is not needed due to `ident` being memset'd to 0 just before
> the copy.
>
> Considering the 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@vger.kernel.org
> Signed-off-by: Justin Stitt <justinstitt@google.com>

Thanks, I suspected this was coming soon :-)

Reviewed-by: Shannon Nelson <shannon.nelson@amd.com>

> ---
> Note: build-tested only.
>
> Found with: $ rg "strncpy\("
> ---
> drivers/net/ethernet/pensando/ionic/ionic_main.c | 4 ++--
> 1 file changed, 2 insertions(+), 2 deletions(-)
>
> diff --git a/drivers/net/ethernet/pensando/ionic/ionic_main.c b/drivers/net/ethernet/pensando/ionic/ionic_main.c
> index 1dc79cecc5cc..835577392178 100644
> --- a/drivers/net/ethernet/pensando/ionic/ionic_main.c
> +++ b/drivers/net/ethernet/pensando/ionic/ionic_main.c
> @@ -554,8 +554,8 @@ int ionic_identify(struct ionic *ionic)
> memset(ident, 0, sizeof(*ident));
>
> ident->drv.os_type = cpu_to_le32(IONIC_OS_TYPE_LINUX);
> - strncpy(ident->drv.driver_ver_str, UTS_RELEASE,
> - sizeof(ident->drv.driver_ver_str) - 1);
> + strscpy(ident->drv.driver_ver_str, UTS_RELEASE,
> + sizeof(ident->drv.driver_ver_str));
>
> mutex_lock(&ionic->dev_cmd_lock);
>
>
> ---
> base-commit: cbf3a2cb156a2c911d8f38d8247814b4c07f49a2
> change-id: 20231011-strncpy-drivers-net-ethernet-pensando-ionic-ionic_main-c-709f8f1ea312
>
> Best regards,
> --
> Justin Stitt <justinstitt@google.com>
>