2023-09-15 23:53:54

by Kees Cook

Subject: [PATCH] leds: qcom-lpg: Annotate struct lpg_led 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 lpg_led.

[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: Bjorn Andersson <[email protected]>
Cc: "Uwe Kleine-König" <[email protected]>
Cc: Douglas Anderson <[email protected]>
Cc: Anjelique Melendez <[email protected]>
Cc: [email protected]
Signed-off-by: Kees Cook <[email protected]>
---
drivers/leds/rgb/leds-qcom-lpg.c | 2 +-
1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/drivers/leds/rgb/leds-qcom-lpg.c b/drivers/leds/rgb/leds-qcom-lpg.c
index df469aaa7e6e..7d93e02a030a 100644
--- a/drivers/leds/rgb/leds-qcom-lpg.c
+++ b/drivers/leds/rgb/leds-qcom-lpg.c
@@ -173,7 +173,7 @@ struct lpg_led {
struct led_classdev_mc mcdev;

unsigned int num_channels;
- struct lpg_channel *channels[];
+ struct lpg_channel *channels[] __counted_by(num_channels);
};

/**
--
2.34.1

2023-09-16 00:43:42

by Gustavo A. R. Silva

Subject: Re: [PATCH] leds: qcom-lpg: Annotate struct lpg_led with __counted_by

On 9/15/23 14:11, 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 lpg_led.
>
> [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: Bjorn Andersson <[email protected]>
> Cc: "Uwe Kleine-König" <[email protected]>
> Cc: Douglas Anderson <[email protected]>
> Cc: Anjelique Melendez <[email protected]>
> Cc: [email protected]
> Signed-off-by: Kees Cook <[email protected]>

Reviewed-by: Gustavo A. R. Silva <[email protected]>

Thanks
--
Gustavo

> ---
> drivers/leds/rgb/leds-qcom-lpg.c | 2 +-
> 1 file changed, 1 insertion(+), 1 deletion(-)
>
> diff --git a/drivers/leds/rgb/leds-qcom-lpg.c b/drivers/leds/rgb/leds-qcom-lpg.c
> index df469aaa7e6e..7d93e02a030a 100644
> --- a/drivers/leds/rgb/leds-qcom-lpg.c
> +++ b/drivers/leds/rgb/leds-qcom-lpg.c
> @@ -173,7 +173,7 @@ struct lpg_led {
> struct led_classdev_mc mcdev;
>
> unsigned int num_channels;
> - struct lpg_channel *channels[];
> + struct lpg_channel *channels[] __counted_by(num_channels);
> };
>
> /**

2023-09-20 14:54:39

by Lee Jones

Subject: Re: (subset) [PATCH] leds: qcom-lpg: Annotate struct lpg_led with __counted_by

On Fri, 15 Sep 2023 13:11:00 -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 lpg_led.
>
> [...]

Applied, thanks!

[1/1] leds: qcom-lpg: Annotate struct lpg_led with __counted_by
commit: 3a2a14ad346d60da60aef0a2afc1fb256a56c83c

--
Lee Jones [李琼斯]