Re: [PATCH] leds: lm3697: Annotate struct lm3697 with __counted_by

From: Gustavo A. R. Silva
Date: Fri Sep 15 2023 - 16:47:11 EST




On 9/15/23 14:10, 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 lm3697.

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

Cc: Pavel Machek <pavel@xxxxxx>
Cc: Lee Jones <lee@xxxxxxxxxx>
Cc: linux-leds@xxxxxxxxxxxxxxx
Signed-off-by: Kees Cook <keescook@xxxxxxxxxxxx>

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

Thanks
--
Gustavo

---
drivers/leds/leds-lm3697.c | 2 +-
1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/drivers/leds/leds-lm3697.c b/drivers/leds/leds-lm3697.c
index cfb8ac220db6..380d17a58fe9 100644
--- a/drivers/leds/leds-lm3697.c
+++ b/drivers/leds/leds-lm3697.c
@@ -89,7 +89,7 @@ struct lm3697 {
int bank_cfg;
int num_banks;
- struct lm3697_led leds[];
+ struct lm3697_led leds[] __counted_by(num_banks);
};
static const struct reg_default lm3697_reg_defs[] = {