2023-09-16 03:55:53

by Kees Cook

Subject: [PATCH] leds: gpio: Annotate struct gpio_leds_priv with __counted_by

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 gpio_leds_priv.

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

Cc: Pavel Machek <[email protected]>
Cc: Lee Jones <[email protected]>
Cc: [email protected]
Signed-off-by: Kees Cook <[email protected]>
---
drivers/leds/leds-gpio.c | 2 +-
1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/drivers/leds/leds-gpio.c b/drivers/leds/leds-gpio.c
index 7bfe40a6bfdd..a6597f0f3eb4 100644
--- a/drivers/leds/leds-gpio.c
+++ b/drivers/leds/leds-gpio.c
@@ -142,7 +142,7 @@ static int create_gpio_led(const struct gpio_led *template,

struct gpio_leds_priv {
int num_leds;
- struct gpio_led_data leds[];
+ struct gpio_led_data leds[] __counted_by(num_leds);
};

static struct gpio_leds_priv *gpio_leds_create(struct platform_device *pdev)
--
2.34.1

2023-09-20 13:49:22

by Lee Jones

Subject: Re: (subset) [PATCH] leds: gpio: Annotate struct gpio_leds_priv with __counted_by

On Fri, 15 Sep 2023 13:10:04 -0700, 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 gpio_leds_priv.
>
> [...]

Applied, thanks!

[1/1] leds: gpio: Annotate struct gpio_leds_priv with __counted_by
commit: 00f91ead9c8037d044414ae44a0e75ef3df27e6f

--
Lee Jones [李琼斯]