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From:   Kees Cook <keescook@chromium.org>
To:     Pavel Machek <pavel@ucw.cz>
Cc:     Kees Cook <keescook@chromium.org>, Lee Jones <lee@kernel.org>,
        linux-leds@vger.kernel.org, Nathan Chancellor <nathan@kernel.org>,
        Nick Desaulniers <ndesaulniers@google.com>,
        Tom Rix <trix@redhat.com>, linux-kernel@vger.kernel.org,
        llvm@lists.linux.dev, linux-hardening@vger.kernel.org
Subject: [PATCH] leds: el15203000: Annotate struct el15203000 with __counted_by
Date:   Fri, 15 Sep 2023 13:09:56 -0700
Message-Id: <20230915200955.never.871-kees@kernel.org>
MIME-Version: 1.0
Content-Transfer-Encoding: 8bit
Precedence: bulk

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 <pavel@ucw.cz>
Cc: Lee Jones <lee@kernel.org>
Cc: linux-leds@vger.kernel.org
Signed-off-by: Kees Cook <keescook@chromium.org>
---
 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