Received-SPF: pass (google.com: domain of linux-kernel-owner@vger.kernel.org designates 23.128.96.31 as permitted sender) client-ip=23.128.96.31;
Message-ID: <d2287237-3137-bc11-c95b-e218b07ff9af@embeddedor.com>
Date:   Sat, 23 Sep 2023 10:37:20 -0600
MIME-Version: 1.0
User-Agent: Mozilla/5.0 (X11; Linux x86_64; rv:102.0) Gecko/20100101
 Thunderbird/102.15.1
Subject: Re: [PATCH] mfd: iqs62x: Annotate struct iqs62x_fw_blk with
 __counted_by
Content-Language: en-US
To:     Kees Cook <keescook@chromium.org>, Lee Jones <lee@kernel.org>
Cc:     Nathan Chancellor <nathan@kernel.org>,
        Nick Desaulniers <ndesaulniers@google.com>,
        Tom Rix <trix@redhat.com>, linux-kernel@vger.kernel.org,
        llvm@lists.linux.dev, linux-hardening@vger.kernel.org
References: <20230922175337.work.150-kees@kernel.org>
From:   "Gustavo A. R. Silva" <gustavo@embeddedor.com>
In-Reply-To: <20230922175337.work.150-kees@kernel.org>
Content-Type: text/plain; charset=UTF-8; format=flowed
Content-Transfer-Encoding: 7bit
Precedence: bulk


On 9/22/23 11:53, 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 iqs62x_fw_blk.
> 
> [1] https://github.com/kees/kernel-tools/blob/trunk/coccinelle/examples/counted_by.cocci
> 
> Cc: Lee Jones <lee@kernel.org>
> Signed-off-by: Kees Cook <keescook@chromium.org>

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

Thanks
-- 
Gustavo

> ---
>   drivers/mfd/iqs62x.c | 2 +-
>   1 file changed, 1 insertion(+), 1 deletion(-)
> 
> diff --git a/drivers/mfd/iqs62x.c b/drivers/mfd/iqs62x.c
> index e03b4d38fbb0..1b465590567c 100644
> --- a/drivers/mfd/iqs62x.c
> +++ b/drivers/mfd/iqs62x.c
> @@ -96,7 +96,7 @@ struct iqs62x_fw_blk {
>   	u8 addr;
>   	u8 mask;
>   	u8 len;
> -	u8 data[];
> +	u8 data[] __counted_by(len);
>   };
>   
>   struct iqs62x_info {