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References: <20211104014039.26772-1-zhiyong.tao@mediatek.com> <20211104014039.26772-2-zhiyong.tao@mediatek.com>
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From:   Sean Wang <sean.wang@kernel.org>
Date:   Wed, 3 Nov 2021 23:07:55 -0700
Message-ID: <CAGp9LzpEG_6w6fvmjaBAW3ihKQZm4uMEy9-5MaLLWkeu+QFqeQ@mail.gmail.com>
Subject: Re: [PATCH] pinctrl: mediatek: fix global-out-of-bounds issue
To:     Zhiyong Tao <zhiyong.tao@mediatek.com>
Cc:     Rob Herring <robh+dt@kernel.org>,
        Linus Walleij <linus.walleij@linaro.org>,
        Mark Rutland <mark.rutland@arm.com>,
        Matthias Brugger <matthias.bgg@gmail.com>,
        srv_heupstream <srv_heupstream@mediatek.com>,
        hui.liu@mediatek.com, Light Hsieh <light.hsieh@mediatek.com>,
        =?UTF-8?B?U2VhbiBXYW5nICjnjovlv5fkupgp?= <sean.wang@mediatek.com>,
        Seiya Wang <seiya.wang@mediatek.com>, rex-bc.chen@mediatek.com,
        "open list:OPEN FIRMWARE AND FLATTENED DEVICE TREE BINDINGS" 
        <devicetree@vger.kernel.org>, lkml <linux-kernel@vger.kernel.org>,
        linux-arm Mailing List <linux-arm-kernel@lists.infradead.org>,
        "moderated list:ARM/Mediatek SoC support" 
        <linux-mediatek@lists.infradead.org>,
        "open list:GPIO SUBSYSTEM" <linux-gpio@vger.kernel.org>,
        Guodong Liu <guodong.liu@mediatek.corp-partner.google.com>
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HI, Zhiyong

On Wed, Nov 3, 2021 at 6:40 PM Zhiyong Tao <zhiyong.tao@mediatek.com> wrote:
>
> From: Guodong Liu <guodong.liu@mediatek.corp-partner.google.com>
>
> When eint virtual eint number is greater than gpio number,
> it maybe produce 'desc[eint_n]' size globle-out-of-bounds issue.
>
> Signed-off-by: Zhiyong Tao <zhiyong.tao@mediatek.com>
> Signed-off-by: Guodong Liu <guodong.liu@mediatek.corp-partner.google.com>
> ---
>  drivers/pinctrl/mediatek/pinctrl-mtk-common-v2.c | 3 ++-
>  1 file changed, 2 insertions(+), 1 deletion(-)
>
> diff --git a/drivers/pinctrl/mediatek/pinctrl-mtk-common-v2.c b/drivers/pinctrl/mediatek/pinctrl-mtk-common-v2.c
> index 45ebdeba985a..9d57c897835c 100644
> --- a/drivers/pinctrl/mediatek/pinctrl-mtk-common-v2.c
> +++ b/drivers/pinctrl/mediatek/pinctrl-mtk-common-v2.c
> @@ -286,7 +286,8 @@ static int mtk_xt_get_gpio_n(void *data, unsigned long eint_n,
>         *gpio_chip = &hw->chip;
>
>         /* Be greedy to guess first gpio_n is equal to eint_n */
> -       if (desc[eint_n].eint.eint_n == eint_n)
> +       if (((*gpio_chip)->ngpio > eint_n) &&

please use "hw->soc->npins > eint_n" to perform the boundary check to
be consistent with the other places for the same purpose

> +           desc[eint_n].eint.eint_n == eint_n)
>                 *gpio_n = eint_n;
>         else
>                 *gpio_n = mtk_xt_find_eint_num(hw, eint_n);
> --
> 2.25.1
>