Received-SPF: pass (google.com: domain of linux-kernel-owner@vger.kernel.org designates 2620:137:e000::3:1 as permitted sender) client-ip=2620:137:e000::3:1;
Message-ID: <92da7e0d-0096-7407-1fc5-fc026c5e446d@linaro.org>
Date:   Mon, 18 Sep 2023 08:21:03 +0300
MIME-Version: 1.0
User-Agent: Mozilla/5.0 (X11; Linux x86_64; rv:102.0) Gecko/20100101
 Thunderbird/102.15.0
Subject: Re: [PATCH] mtd: rawnand: atmel: Annotate struct atmel_nand with
 __counted_by
To:     Kees Cook <keescook@chromium.org>
Cc:     Miquel Raynal <miquel.raynal@bootlin.com>,
        Richard Weinberger <richard@nod.at>,
        Vignesh Raghavendra <vigneshr@ti.com>,
        Nicolas Ferre <nicolas.ferre@microchip.com>,
        Alexandre Belloni <alexandre.belloni@bootlin.com>,
        Claudiu Beznea <claudiu.beznea@tuxon.dev>,
        linux-mtd@lists.infradead.org,
        linux-arm-kernel@lists.infradead.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, linux-hardening@vger.kernel.org
References: <20230915201219.never.352-kees@kernel.org>
From:   Tudor Ambarus <tudor.ambarus@linaro.org>
Content-Language: en-US
In-Reply-To: <20230915201219.never.352-kees@kernel.org>
Content-Type: text/plain; charset=UTF-8
Content-Transfer-Encoding: 7bit
Precedence: bulk


On 15.09.2023 23:12, 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 atmel_nand.
> 
> [1] https://github.com/kees/kernel-tools/blob/trunk/coccinelle/examples/counted_by.cocci
> 
> Cc: Tudor Ambarus <tudor.ambarus@linaro.org>
> Cc: Miquel Raynal <miquel.raynal@bootlin.com>
> Cc: Richard Weinberger <richard@nod.at>
> Cc: Vignesh Raghavendra <vigneshr@ti.com>
> Cc: Nicolas Ferre <nicolas.ferre@microchip.com>
> Cc: Alexandre Belloni <alexandre.belloni@bootlin.com>
> Cc: Claudiu Beznea <claudiu.beznea@tuxon.dev>
> Cc: linux-mtd@lists.infradead.org
> Cc: linux-arm-kernel@lists.infradead.org
> Signed-off-by: Kees Cook <keescook@chromium.org>

Reviewed-by: Tudor Ambarus <tudor.ambarus@linaro.org>
> ---
>  drivers/mtd/nand/raw/atmel/nand-controller.c | 2 +-
>  1 file changed, 1 insertion(+), 1 deletion(-)
> 
> diff --git a/drivers/mtd/nand/raw/atmel/nand-controller.c b/drivers/mtd/nand/raw/atmel/nand-controller.c
> index 3f494f7c7ecb..4cb478bbee4a 100644
> --- a/drivers/mtd/nand/raw/atmel/nand-controller.c
> +++ b/drivers/mtd/nand/raw/atmel/nand-controller.c
> @@ -165,7 +165,7 @@ struct atmel_nand {
>  	struct atmel_pmecc_user *pmecc;
>  	struct gpio_desc *cdgpio;
>  	int numcs;
> -	struct atmel_nand_cs cs[];
> +	struct atmel_nand_cs cs[] __counted_by(numcs);
>  };
>  
>  static inline struct atmel_nand *to_atmel_nand(struct nand_chip *chip)