Date: Thu, 12 Nov 2015 14:55:49 +0100
From: Thierry Reding <thierry.reding@gmail.com>
To: Jon Hunter <jonathanh@nvidia.com>
Cc: LABBE Corentin <clabbe.montjoie@gmail.com>, gnurou@gmail.com,
        ldewangan@nvidia.com, swarren@wwwdotorg.org, wsa@the-dreams.de,
        linux-i2c@vger.kernel.org, linux-kernel@vger.kernel.org,
        linux-tegra@vger.kernel.org
Subject: Re: [PATCH] i2c: tegra: fix a possible NULL dereference
Message-ID: <20151112135549.GB1131@ulmo>
References: <1447313163-23848-1-git-send-email-clabbe.montjoie@gmail.com>
 <20151112122923.GA31671@ulmo>
 <564496E8.60106@nvidia.com>
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On Thu, Nov 12, 2015 at 01:40:56PM +0000, Jon Hunter wrote:
>=20
> On 12/11/15 12:29, Thierry Reding wrote:
> > * PGP Signed by an unknown key
> >=20
> > On Thu, Nov 12, 2015 at 08:26:03AM +0100, LABBE Corentin wrote:
> >> of_match_device could return NULL, and so cause a NULL pointer
> >=20
> > No. There is no way that of_match_device() can ever fail. The driver
> > core uses the same table to match the OF device to the driver, so the
> > only case where of_match_device() would return NULL is if no match was
> > found, in which case the tegra_i2c_probe() function would never have
> > been called in the first place.
>=20
> Right and so ...
>=20
> >> dereference later at line 809:
> >> i2c_dev->hw =3D match->data;
> >>
> >> Signed-off-by: LABBE Corentin <clabbe.montjoie@gmail.com>
> >> ---
> >>  drivers/i2c/busses/i2c-tegra.c | 3 +++
> >>  1 file changed, 3 insertions(+)
> >>
> >> diff --git a/drivers/i2c/busses/i2c-tegra.c b/drivers/i2c/busses/i2c-t=
egra.c
> >> index a0522fc..c803551 100644
> >> --- a/drivers/i2c/busses/i2c-tegra.c
> >> +++ b/drivers/i2c/busses/i2c-tegra.c
> >> @@ -806,7 +806,10 @@ static int tegra_i2c_probe(struct platform_device=
 *pdev)
> >> =20
> >>  	if (pdev->dev.of_node) {
>=20
> Can we get rid of this if-statement?

Yeah, I guess we can drop that, too. It's been a long time since Tegra
was converted to OF only.

Thierry

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