Re: [PATCH] ASoC: apple: mca: Annotate struct mca_data with __counted_by

[Gustavo A. R. Silva]

On 9/22/23 11:50, 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 mca_data.
>
> [1] https://github.com/kees/kernel-tools/blob/trunk/coccinelle/examples/counted_by.cocci
>
> Cc: "Martin Povišer" <povik+lin@xxxxxxxxxxx>
> Cc: Liam Girdwood <lgirdwood@xxxxxxxxx>
> Cc: Mark Brown <broonie@xxxxxxxxxx>
> Cc: Jaroslav Kysela <perex@xxxxxxxx>
> Cc: Takashi Iwai <tiwai@xxxxxxxx>
> Cc: asahi@xxxxxxxxxxxxxxx
> Cc: alsa-devel@xxxxxxxxxxxxxxxx
> Signed-off-by: Kees Cook <keescook@xxxxxxxxxxxx>

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

Thanks
--
Gustavo

> ---
>   sound/soc/apple/mca.c | 2 +-
>   1 file changed, 1 insertion(+), 1 deletion(-)
>
> diff --git a/sound/soc/apple/mca.c b/sound/soc/apple/mca.c
> index ce77934f3eef..99e547ef95e6 100644
> --- a/sound/soc/apple/mca.c
> +++ b/sound/soc/apple/mca.c
> @@ -161,7 +161,7 @@ struct mca_data {
>   	struct mutex port_mutex;
>   
>   	int nclusters;
> -	struct mca_cluster clusters[];
> +	struct mca_cluster clusters[] __counted_by(nclusters);
>   };
>   
>   static void mca_modify(struct mca_cluster *cl, int regoffset, u32 mask, u32 val)