Re: [PATCH] drm/nouveau/nvif: refactor deprecated strncpy

From: Lyude Paul
Date: Fri Sep 15 2023 - 13:37:10 EST


Reviewed-by: Lyude Paul <lyude@xxxxxxxxxx>

Will push this and your other patches in just a moment

On Thu, 2023-09-14 at 21:30 +0000, Justin Stitt wrote:
> `strncpy` is deprecated and as such we should prefer more robust and
> less ambiguous string interfaces.
>
> A suitable replacement is `strscpy_pad` due to the fact that it
> guarantees NUL-termination on the destination buffer whilst also
> maintaining the NUL-padding behavior that `strncpy` provides. I am not
> sure whether NUL-padding is strictly needed but I see in
> `nvif_object_ctor()` args is memcpy'd elsewhere so I figured we'd keep
> the same functionality.
>
> Link: https://www.kernel.org/doc/html/latest/process/deprecated.html#strncpy-on-nul-terminated-strings [1]
> Link: https://github.com/KSPP/linux/issues/90
> Cc: linux-hardening@xxxxxxxxxxxxxxx
> Signed-off-by: Justin Stitt <justinstitt@xxxxxxxxxx>
> ---
> Note: build-tested only.
> ---
> drivers/gpu/drm/nouveau/nvif/client.c | 2 +-
> 1 file changed, 1 insertion(+), 1 deletion(-)
>
> diff --git a/drivers/gpu/drm/nouveau/nvif/client.c b/drivers/gpu/drm/nouveau/nvif/client.c
> index a3264a0e933a..3a27245f467f 100644
> --- a/drivers/gpu/drm/nouveau/nvif/client.c
> +++ b/drivers/gpu/drm/nouveau/nvif/client.c
> @@ -69,7 +69,7 @@ nvif_client_ctor(struct nvif_client *parent, const char *name, u64 device,
> } nop = {};
> int ret;
>
> - strncpy(args.name, name, sizeof(args.name));
> + strscpy_pad(args.name, name, sizeof(args.name));
> ret = nvif_object_ctor(parent != client ? &parent->object : NULL,
> name ? name : "nvifClient", 0,
> NVIF_CLASS_CLIENT, &args, sizeof(args),
>
> ---
> base-commit: 3669558bdf354cd352be955ef2764cde6a9bf5ec
> change-id: 20230914-strncpy-drivers-gpu-drm-nouveau-nvif-client-c-82b023c36953
>
> Best regards,
> --
> Justin Stitt <justinstitt@xxxxxxxxxx>
>

--
Cheers,
Lyude Paul (she/her)
Software Engineer at Red Hat