Received-SPF: pass (google.com: domain of linux-kernel-owner@vger.kernel.org designates 2620:137:e000::3:3 as permitted sender) client-ip=2620:137:e000::3:3;
From:   Kees Cook <keescook@chromium.org>
To:     Pavel Machek <pavel@ucw.cz>
Cc:     Kees Cook <keescook@chromium.org>, Lee Jones <lee@kernel.org>,
        Matthias Brugger <matthias.bgg@gmail.com>,
        AngeloGioacchino Del Regno 
        <angelogioacchino.delregno@collabora.com>,
        Alice Chen <alice_chen@richtek.com>,
        Jacek Anaszewski <jacek.anaszewski@gmail.com>,
        ChiYuan Huang <cy_huang@richtek.com>,
        ChiaEn Wu <chiaen_wu@richtek.com>,
        kernel test robot <lkp@intel.com>,
        linux-leds@vger.kernel.org, linux-arm-kernel@lists.infradead.org,
        linux-mediatek@lists.infradead.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: mt6370: Annotate struct mt6370_priv with __counted_by
Date:   Fri, 15 Sep 2023 13:10:52 -0700
Message-Id: <20230915201051.never.429-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 mt6370_priv.

[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: Matthias Brugger <matthias.bgg@gmail.com>
Cc: AngeloGioacchino Del Regno <angelogioacchino.delregno@collabora.com>
Cc: Alice Chen <alice_chen@richtek.com>
Cc: Jacek Anaszewski <jacek.anaszewski@gmail.com>
Cc: ChiYuan Huang <cy_huang@richtek.com>
Cc: ChiaEn Wu <chiaen_wu@richtek.com>
Cc: kernel test robot <lkp@intel.com>
Cc: linux-leds@vger.kernel.org
Cc: linux-arm-kernel@lists.infradead.org
Cc: linux-mediatek@lists.infradead.org
Signed-off-by: Kees Cook <keescook@chromium.org>
---
 drivers/leds/flash/leds-mt6370-flash.c | 2 +-
 drivers/leds/rgb/leds-mt6370-rgb.c     | 2 +-
 2 files changed, 2 insertions(+), 2 deletions(-)

diff --git a/drivers/leds/flash/leds-mt6370-flash.c b/drivers/leds/flash/leds-mt6370-flash.c
index 931067c8a75f..912d9d622320 100644
--- a/drivers/leds/flash/leds-mt6370-flash.c
+++ b/drivers/leds/flash/leds-mt6370-flash.c
@@ -81,7 +81,7 @@ struct mt6370_priv {
 	unsigned int fled_torch_used;
 	unsigned int leds_active;
 	unsigned int leds_count;
-	struct mt6370_led leds[];
+	struct mt6370_led leds[] __counted_by(leds_count);
 };
 
 static int mt6370_torch_brightness_set(struct led_classdev *lcdev, enum led_brightness level)
diff --git a/drivers/leds/rgb/leds-mt6370-rgb.c b/drivers/leds/rgb/leds-mt6370-rgb.c
index bb62431efe83..448d0da11848 100644
--- a/drivers/leds/rgb/leds-mt6370-rgb.c
+++ b/drivers/leds/rgb/leds-mt6370-rgb.c
@@ -153,7 +153,7 @@ struct mt6370_priv {
 	const struct mt6370_pdata *pdata;
 	unsigned int leds_count;
 	unsigned int leds_active;
-	struct mt6370_led leds[];
+	struct mt6370_led leds[] __counted_by(leds_count);
 };
 
 static const struct reg_field common_reg_fields[F_MAX_FIELDS] = {
-- 
2.34.1