Re: [PATCH] platform/x86: hp-bioscfg: Annotate struct bios_args with __counted_by

[Gustavo A. R. Silva]

On Fri, Sep 22, 2023 at 10:54:21AM -0700, 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 bios_args.
> 
> [1] https://github.com/kees/kernel-tools/blob/trunk/coccinelle/examples/counted_by.cocci
> 
> Cc: Jorge Lopez <jorge.lopez2@xxxxxx>
> Cc: Hans de Goede <hdegoede@xxxxxxxxxx>
> Cc: Mark Gross <markgross@xxxxxxxxxx>
> Cc: Nathan Chancellor <nathan@xxxxxxxxxx>
> Cc: Nick Desaulniers <ndesaulniers@xxxxxxxxxx>
> Cc: Tom Rix <trix@xxxxxxxxxx>
> Cc: platform-driver-x86@xxxxxxxxxxxxxxx
> Cc: llvm@xxxxxxxxxxxxxxx
> Signed-off-by: Kees Cook <keescook@xxxxxxxxxxxx>

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

Thanks
--
Gustavo

> ---
>  drivers/platform/x86/hp/hp-bioscfg/biosattr-interface.c | 2 +-
>  1 file changed, 1 insertion(+), 1 deletion(-)
> 
> diff --git a/drivers/platform/x86/hp/hp-bioscfg/biosattr-interface.c b/drivers/platform/x86/hp/hp-bioscfg/biosattr-interface.c
> index dea54f35b8b5..4da99cb7218d 100644
> --- a/drivers/platform/x86/hp/hp-bioscfg/biosattr-interface.c
> +++ b/drivers/platform/x86/hp/hp-bioscfg/biosattr-interface.c
> @@ -19,7 +19,7 @@ struct bios_args {
>  	u32 command;
>  	u32 commandtype;
>  	u32 datasize;
> -	u8 data[];
> +	u8 data[] __counted_by(datasize);
>  };
>  
>  /**
> -- 
> 2.34.1
> 
>