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Message-ID: <3b98d3af-02ef-8929-1e6b-7287f470df2a@embeddedor.com>
Date:   Fri, 15 Sep 2023 14:47:56 -0600
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Subject: Re: [PATCH] leds: qcom-lpg: Annotate struct lpg_led with __counted_by
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To:     Kees Cook <keescook@chromium.org>, Pavel Machek <pavel@ucw.cz>
Cc:     Lee Jones <lee@kernel.org>,
        Bjorn Andersson <quic_bjorande@quicinc.com>,
        =?UTF-8?Q?Uwe_Kleine-K=c3=b6nig?= <u.kleine-koenig@pengutronix.de>,
        Douglas Anderson <dianders@chromium.org>,
        Anjelique Melendez <quic_amelende@quicinc.com>,
        linux-leds@vger.kernel.org, Nathan Chancellor <nathan@kernel.org>,
        Nick Desaulniers <ndesaulniers@google.com>,
        Tom Rix <trix@redhat.com>,
        Neil Armstrong <neil.armstrong@linaro.org>,
        Luca Weiss <luca@z3ntu.xyz>, Lu Hongfei <luhongfei@vivo.com>,
        Dmitry Baryshkov <dmitry.baryshkov@linaro.org>,
        linux-kernel@vger.kernel.org, llvm@lists.linux.dev,
        linux-hardening@vger.kernel.org
References: <20230915201059.never.086-kees@kernel.org>
From:   "Gustavo A. R. Silva" <gustavo@embeddedor.com>
In-Reply-To: <20230915201059.never.086-kees@kernel.org>
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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 <pavel@ucw.cz>
> Cc: Lee Jones <lee@kernel.org>
> Cc: Bjorn Andersson <quic_bjorande@quicinc.com>
> Cc: "Uwe Kleine-König" <u.kleine-koenig@pengutronix.de>
> Cc: Douglas Anderson <dianders@chromium.org>
> Cc: Anjelique Melendez <quic_amelende@quicinc.com>
> Cc: linux-leds@vger.kernel.org
> Signed-off-by: Kees Cook <keescook@chromium.org>

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

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);
>   };
>   
>   /**