eeprom: at24: Annotate struct at24_data with __counted_by

[PATCH] eeprom: at24: Annotate struct at24_data with __counted_by

Posted by Kees Cook 2 years, 2 months ago

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 at24_data.

[1] https://github.com/kees/kernel-tools/blob/trunk/coccinelle/examples/counted_by.cocci

Cc: Bartosz Golaszewski <brgl@bgdev.pl>
Cc: Arnd Bergmann <arnd@arndb.de>
Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Cc: linux-i2c@vger.kernel.org
Signed-off-by: Kees Cook <keescook@chromium.org>
---
 drivers/misc/eeprom/at24.c | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/drivers/misc/eeprom/at24.c b/drivers/misc/eeprom/at24.c
index af83aca452b7..7dfd7fdb423e 100644
--- a/drivers/misc/eeprom/at24.c
+++ b/drivers/misc/eeprom/at24.c
@@ -92,7 +92,7 @@ struct at24_data {
 	 * them for us.
 	 */
 	u8 bank_addr_shift;
-	struct regmap *client_regmaps[];
+	struct regmap *client_regmaps[] __counted_by(num_addresses);
 };
 
 /*
-- 
2.34.1

Re: [PATCH] eeprom: at24: Annotate struct at24_data with __counted_by

Posted by Bartosz Golaszewski 2 years, 2 months ago

On Fri, Sep 22, 2023 at 7:51 PM Kees Cook <keescook@chromium.org> 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 at24_data.
>
> [1] https://github.com/kees/kernel-tools/blob/trunk/coccinelle/examples/counted_by.cocci
>
> Cc: Bartosz Golaszewski <brgl@bgdev.pl>
> Cc: Arnd Bergmann <arnd@arndb.de>
> Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
> Cc: linux-i2c@vger.kernel.org
> Signed-off-by: Kees Cook <keescook@chromium.org>
> ---
>  drivers/misc/eeprom/at24.c | 2 +-
>  1 file changed, 1 insertion(+), 1 deletion(-)
>
> diff --git a/drivers/misc/eeprom/at24.c b/drivers/misc/eeprom/at24.c
> index af83aca452b7..7dfd7fdb423e 100644
> --- a/drivers/misc/eeprom/at24.c
> +++ b/drivers/misc/eeprom/at24.c
> @@ -92,7 +92,7 @@ struct at24_data {
>          * them for us.
>          */
>         u8 bank_addr_shift;
> -       struct regmap *client_regmaps[];
> +       struct regmap *client_regmaps[] __counted_by(num_addresses);
>  };
>
>  /*
> --
> 2.34.1
>

Applied, thanks!

Bart

Re: [PATCH] eeprom: at24: Annotate struct at24_data with __counted_by

Posted by Gustavo A. R. Silva 2 years, 2 months ago


On 9/22/23 11:51, 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 at24_data.
> 
> [1] https://github.com/kees/kernel-tools/blob/trunk/coccinelle/examples/counted_by.cocci
> 
> Cc: Bartosz Golaszewski <brgl@bgdev.pl>
> Cc: Arnd Bergmann <arnd@arndb.de>
> Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
> Cc: linux-i2c@vger.kernel.org
> Signed-off-by: Kees Cook <keescook@chromium.org>

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

Thanks
-- 
Gustavo

> ---
>   drivers/misc/eeprom/at24.c | 2 +-
>   1 file changed, 1 insertion(+), 1 deletion(-)
> 
> diff --git a/drivers/misc/eeprom/at24.c b/drivers/misc/eeprom/at24.c
> index af83aca452b7..7dfd7fdb423e 100644
> --- a/drivers/misc/eeprom/at24.c
> +++ b/drivers/misc/eeprom/at24.c
> @@ -92,7 +92,7 @@ struct at24_data {
>   	 * them for us.
>   	 */
>   	u8 bank_addr_shift;
> -	struct regmap *client_regmaps[];
> +	struct regmap *client_regmaps[] __counted_by(num_addresses);
>   };
>   
>   /*