MIME-Version: 1.0
References: <20230226095933.3286710-1-void0red@gmail.com> <Y/t729AIYjxuP6X6@corigine.com>
In-Reply-To: <Y/t729AIYjxuP6X6@corigine.com>
From:   Kang Chen <void0red@gmail.com>
Date:   Mon, 27 Feb 2023 09:26:45 +0800
Message-ID: <CANE+tVrFOev4GjjbM1=P4gPHJEqLvbMHJfYfVH_L6NVVDnu0DA@mail.gmail.com>
Subject: Re: [PATCH] nfc: fdp: add null check of devm_kmalloc_array in fdp_nci_i2c_read_device_properties
To:     Simon Horman <simon.horman@corigine.com>
Cc:     krzysztof.kozlowski@linaro.org, netdev@vger.kernel.org,
        linux-kernel@vger.kernel.org
Content-Type: text/plain; charset="UTF-8"
Content-Transfer-Encoding: quoted-printable
Precedence: bulk

Hi Simon,

I will update the patch later.
Thank you for your review.

On Sun, Feb 26, 2023 at 11:33=E2=80=AFPM Simon Horman <simon.horman@corigin=
e.com> wrote:
>
> On Sun, Feb 26, 2023 at 05:59:33PM +0800, Kang Chen wrote:
> > devm_kmalloc_array may fails, *fw_vsc_cfg might be null and cause
> > out-of-bounds write in device_property_read_u8_array later.
> >
> > Signed-off-by: Kang Chen <void0red@gmail.com>
>
> I'm not sure if this is a bug-fix (for stable).
> But if so, I think the following is the appropriate fixes tag.
>
> Fixes: a06347c04c13 ("NFC: Add Intel Fields Peak NFC solution driver")
>
> > ---
> >  drivers/nfc/fdp/i2c.c | 3 +++
> >  1 file changed, 3 insertions(+)
> >
> > diff --git a/drivers/nfc/fdp/i2c.c b/drivers/nfc/fdp/i2c.c
> > index 2d53e0f88..d95d20efa 100644
> > --- a/drivers/nfc/fdp/i2c.c
> > +++ b/drivers/nfc/fdp/i2c.c
> > @@ -247,6 +247,9 @@ static void fdp_nci_i2c_read_device_properties(stru=
ct device *dev,
> >                                          len, sizeof(**fw_vsc_cfg),
> >                                          GFP_KERNEL);
> >
> > +             if (!*fw_vsc_cfg)
> > +                     goto vsc_read_err;
>
> This leads to:
>
>         dev_dbg(dev, "FW vendor specific commands not present\n");
>
> Which seems a little misleading for this error condition.
>
> > +
> >               r =3D device_property_read_u8_array(dev, FDP_DP_FW_VSC_CF=
G_NAME,
> >                                                 *fw_vsc_cfg, len);
> >
> > --
> > 2.34.1
> >