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From:   Linus Walleij <linus.walleij@linaro.org>
Date:   Wed, 15 Mar 2023 14:15:13 +0100
Message-ID: <CACRpkdbowrfYZpNKA32S8GT=8x_h+ZW4gd2Kj6FZkP1SZmDEPw@mail.gmail.com>
Subject: Re: [PATCH net 1/2] net: dsa: realtek: fix out-of-bounds access
To:     Ahmad Fatoum <a.fatoum@pengutronix.de>
Cc:     =?UTF-8?Q?Alvin_=C5=A0ipraga?= <alsi@bang-olufsen.dk>,
        Andrew Lunn <andrew@lunn.ch>,
        Florian Fainelli <f.fainelli@gmail.com>,
        Vladimir Oltean <olteanv@gmail.com>,
        Luiz Angelo Daros de Luca <luizluca@gmail.com>,
        "David S. Miller" <davem@davemloft.net>, kernel@pengutronix.de,
        Eric Dumazet <edumazet@google.com>,
        Jakub Kicinski <kuba@kernel.org>,
        Paolo Abeni <pabeni@redhat.com>, netdev@vger.kernel.org,
        linux-kernel@vger.kernel.org
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On Wed, Mar 15, 2023 at 2:09=E2=80=AFPM Ahmad Fatoum <a.fatoum@pengutronix.=
de> wrote:

> The probe function sets priv->chip_data to (void *)priv + sizeof(*priv)
> with the expectation that priv has enough trailing space.
>
> However, only realtek-smi actually allocated this chip_data space.
> Do likewise in realtek-mdio to fix out-of-bounds accesses.
>
> Fixes: aac94001067d ("net: dsa: realtek: add new mdio interface for drive=
rs")
> Signed-off-by: Ahmad Fatoum <a.fatoum@pengutronix.de>

Reviewed-by: Linus Walleij <linus.walleij@linaro.org>

That this worked for so long is kind of scary, and the reason why we run Ka=
san
over so much code, I don't know if Kasan would have found this one.

Rewriting the whole world in Rust will fix this problem, but it will
take a while...

Yours,
Linus Walleij