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Date:   Sat, 23 Sep 2023 11:03:56 -0600
From:   "Gustavo A. R. Silva" <gustavoars@kernel.org>
To:     Kees Cook <keescook@chromium.org>
Cc:     Sebastian Reichel <sre@kernel.org>, Chen-Yu Tsai <wens@csie.org>,
        linux-pm@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: Re: [PATCH] power: supply: axp20x_usb_power: Annotate struct
 axp20x_usb_power with __counted_by
Message-ID: <ZQ8afIKwo5DtIciT@work>
References: <20230922175358.work.774-kees@kernel.org>
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On Fri, Sep 22, 2023 at 10:53:58AM -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 axp20x_usb_power.
> 
> [1] https://github.com/kees/kernel-tools/blob/trunk/coccinelle/examples/counted_by.cocci
> 
> Cc: Sebastian Reichel <sre@kernel.org>
> Cc: Chen-Yu Tsai <wens@csie.org>
> Cc: linux-pm@vger.kernel.org
> Signed-off-by: Kees Cook <keescook@chromium.org>

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

Thanks
--
Gustavo

> ---
>  drivers/power/supply/axp20x_usb_power.c | 2 +-
>  1 file changed, 1 insertion(+), 1 deletion(-)
> 
> diff --git a/drivers/power/supply/axp20x_usb_power.c b/drivers/power/supply/axp20x_usb_power.c
> index bde17406c130..e23308ad4cc7 100644
> --- a/drivers/power/supply/axp20x_usb_power.c
> +++ b/drivers/power/supply/axp20x_usb_power.c
> @@ -73,7 +73,7 @@ struct axp20x_usb_power {
>  	unsigned int old_status;
>  	unsigned int online;
>  	unsigned int num_irqs;
> -	unsigned int irqs[];
> +	unsigned int irqs[] __counted_by(num_irqs);
>  };
>  
>  static bool axp20x_usb_vbus_needs_polling(struct axp20x_usb_power *power)
> -- 
> 2.34.1
> 
>