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Message-ID: <00482b1c-c88d-4e84-ba06-92f00dec8f53@embeddedor.com>
Date:   Fri, 6 Oct 2023 22:49:41 +0200
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Subject: Re: [PATCH] wifi: rtw89: coex: Annotate struct
 rtw89_btc_btf_set_slot_table with __counted_by
Content-Language: en-US
To:     Kees Cook <keescook@chromium.org>,
        Ping-Ke Shih <pkshih@realtek.com>
Cc:     Kalle Valo <kvalo@kernel.org>,
        "Gustavo A. R. Silva" <gustavoars@kernel.org>,
        linux-wireless@vger.kernel.org, linux-hardening@vger.kernel.org,
        Nathan Chancellor <nathan@kernel.org>,
        Nick Desaulniers <ndesaulniers@google.com>,
        Tom Rix <trix@redhat.com>, linux-kernel@vger.kernel.org,
        llvm@lists.linux.dev
References: <20231006201715.work.239-kees@kernel.org>
From:   "Gustavo A. R. Silva" <gustavo@embeddedor.com>
In-Reply-To: <20231006201715.work.239-kees@kernel.org>
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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@realtek.com>
> Cc: Kalle Valo <kvalo@kernel.org>
> Cc: "Gustavo A. R. Silva" <gustavoars@kernel.org>
> Cc: linux-wireless@vger.kernel.org
> Cc: linux-hardening@vger.kernel.org
> Link: https://github.com/kees/kernel-tools/blob/trunk/coccinelle/examples/counted_by.cocci [1]
> Signed-off-by: Kees Cook <keescook@chromium.org>

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

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 {