Re: [PATCH] media: allegro: Annotate struct mcu_msg_push_buffers_internal with __counted_by

[Gustavo A. R. Silva]

On 9/22/23 11:49, Kees Cook wrote:
> Prepare for the coming implementation by GCC and Clang of the __counted_by
> attribute. Flexible array members annotated with __counted_by can have
> their accesses bounds-checked at run-time checking via CONFIG_UBSAN_BOUNDS
> (for array indexing) and CONFIG_FORTIFY_SOURCE (for strcpy/memcpy-family
> functions).
>
> As found with Coccinelle[1], add __counted_by for struct mcu_msg_push_buffers_internal.
>
> [1] https://github.com/kees/kernel-tools/blob/trunk/coccinelle/examples/counted_by.cocci
>
> Cc: Michael Tretter <m.tretter@xxxxxxxxxxxxxx>
> Cc: Pengutronix Kernel Team <kernel@xxxxxxxxxxxxxx>
> Cc: Mauro Carvalho Chehab <mchehab@xxxxxxxxxx>
> Cc: linux-media@xxxxxxxxxxxxxxx
> Signed-off-by: Kees Cook <keescook@xxxxxxxxxxxx>

Reviewed-by: Gustavo A. R. Silva <gustavoars@xxxxxxxxxx>

Thanks
--
Gustavo

> ---
>   drivers/media/platform/allegro-dvt/allegro-mail.h | 2 +-
>   1 file changed, 1 insertion(+), 1 deletion(-)
>
> diff --git a/drivers/media/platform/allegro-dvt/allegro-mail.h b/drivers/media/platform/allegro-dvt/allegro-mail.h
> index a5686058d754..c0c9013f1aab 100644
> --- a/drivers/media/platform/allegro-dvt/allegro-mail.h
> +++ b/drivers/media/platform/allegro-dvt/allegro-mail.h
> @@ -184,7 +184,7 @@ struct mcu_msg_push_buffers_internal {
>   	struct mcu_msg_header header;
>   	u32 channel_id;
>   	size_t num_buffers;
> -	struct mcu_msg_push_buffers_internal_buffer buffer[];
> +	struct mcu_msg_push_buffers_internal_buffer buffer[] __counted_by(num_buffers);
>   };
>   
>   struct mcu_msg_put_stream_buffer {