2023-09-16 05:40:49

by Kees Cook

Subject: [PATCH] leds: el15203000: Annotate struct el15203000 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 el15203000.

[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-el15203000.c | 2 +-
1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/drivers/leds/leds-el15203000.c b/drivers/leds/leds-el15203000.c
index 7e7b617bcd56..d40194a3029f 100644
--- a/drivers/leds/leds-el15203000.c
+++ b/drivers/leds/leds-el15203000.c
@@ -80,7 +80,7 @@ struct el15203000 {
struct spi_device *spi;
unsigned long delay;
size_t count;
- struct el15203000_led leds[];
+ struct el15203000_led leds[] __counted_by(count);
};

#define to_el15203000_led(d) container_of(d, struct el15203000_led, ldev)
--
2.34.1

2023-09-20 13:52:17

by Lee Jones

Subject: Re: (subset) [PATCH] leds: el15203000: Annotate struct el15203000 with __counted_by

On Fri, 15 Sep 2023 13:09:56 -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 el15203000.
>
> [...]

Applied, thanks!

[1/1] leds: el15203000: Annotate struct el15203000 with __counted_by
commit: 1d6d5c03fabeb5e5bb7fd7ac3319a8c5471be9e8

--
Lee Jones [李琼斯]