Re: [PATCH] video: mmp: Annotate struct mmp_path with __counted_by

[Gustavo A. R. Silva]

On 9/22/23 11:51, 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 mmp_path.
>
> [1] https://github.com/kees/kernel-tools/blob/trunk/coccinelle/examples/counted_by.cocci
>
> Cc: Helge Deller <deller@xxxxxx>
> Cc: linux-fbdev@xxxxxxxxxxxxxxx
> Cc: dri-devel@xxxxxxxxxxxxxxxxxxxxx
> Signed-off-by: Kees Cook <keescook@xxxxxxxxxxxx>

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

Thanks
--
Gustavo

> ---
>   include/video/mmp_disp.h | 2 +-
>   1 file changed, 1 insertion(+), 1 deletion(-)
>
> diff --git a/include/video/mmp_disp.h b/include/video/mmp_disp.h
> index 77252cb46361..a722dcbf5073 100644
> --- a/include/video/mmp_disp.h
> +++ b/include/video/mmp_disp.h
> @@ -231,7 +231,7 @@ struct mmp_path {
>   
>   	/* layers */
>   	int overlay_num;
> -	struct mmp_overlay overlays[];
> +	struct mmp_overlay overlays[] __counted_by(overlay_num);
>   };
>   
>   extern struct mmp_path *mmp_get_path(const char *name);