Re: [PATCH] wifi: rtw89: coex: Annotate struct rtw89_btc_btf_set_slot_table with __counted_by

[Gustavo A. R. Silva]

On 10/6/23 22:17, 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 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
> rtw89_btc_btf_set_slot_table.
>
> Cc: Ping-Ke Shih <pkshih@xxxxxxxxxxx>
> Cc: Kalle Valo <kvalo@xxxxxxxxxx>
> Cc: "Gustavo A. R. Silva" <gustavoars@xxxxxxxxxx>
> Cc: linux-wireless@xxxxxxxxxxxxxxx
> Cc: linux-hardening@xxxxxxxxxxxxxxx
> Link: https://github.com/kees/kernel-tools/blob/trunk/coccinelle/examples/counted_by.cocci [1]
> Signed-off-by: Kees Cook <keescook@xxxxxxxxxxxx>

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

Thanks!
--
Gustavo

> ---
>   drivers/net/wireless/realtek/rtw89/coex.c | 2 +-
>   1 file changed, 1 insertion(+), 1 deletion(-)
>
> diff --git a/drivers/net/wireless/realtek/rtw89/coex.c b/drivers/net/wireless/realtek/rtw89/coex.c
> index 4ba8b3df70ae..d66a1152c3f5 100644
> --- a/drivers/net/wireless/realtek/rtw89/coex.c
> +++ b/drivers/net/wireless/realtek/rtw89/coex.c
> @@ -237,7 +237,7 @@ struct rtw89_btc_btf_set_report {
>   struct rtw89_btc_btf_set_slot_table {
>   	u8 fver;
>   	u8 tbl_num;
> -	u8 buf[];
> +	u8 buf[] __counted_by(tbl_num);
>   } __packed;
>   
>   struct rtw89_btc_btf_set_mon_reg {