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Date: Mon, 30 Jan 2017 12:15:53 +0100
From: Uwe =?iso-8859-1?Q?Kleine-K=F6nig?= 
        <u.kleine-koenig@pengutronix.de>
To: Thierry Reding <thierry.reding@gmail.com>
Cc: Shailendra Verma <shailendra.v@samsung.com>,
        Laxman Dewangan <ldewangan@nvidia.com>,
        Wolfram Sang <wsa@the-dreams.de>,
        Stephen Warren <swarren@wwwdotorg.org>,
        Alexandre Courbot <gnurou@gmail.com>, linux-i2c@vger.kernel.org,
        linux-tegra@vger.kernel.org, linux-kernel@vger.kernel.org,
        p.shailesh@samsung.com, ashish.kalra@samsung.com,
        Shailendra Verma <shailendra.capricorn@gmail.com>
Subject: Re: [PATCH] I2c: busses - Fix possible NULL derefrence.
Message-ID: <20170130111553.cbwxu23lzd46qtt7@pengutronix.de>
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On Mon, Jan 30, 2017 at 09:54:55AM +0100, Thierry Reding wrote:
> On Mon, Jan 30, 2017 at 09:07:15AM +0100, Uwe Kleine-König wrote:
> > Hello,
> > 
> > On Mon, Jan 30, 2017 at 08:12:17AM +0100, Thierry Reding wrote:
> > > On Mon, Jan 30, 2017 at 10:33:07AM +0530, Shailendra Verma wrote:
> > > > of_device_get_match_data could return NULL, and so can cause
> > > > a NULL pointer dereference later.
> > > > 
> > > > Signed-off-by: Shailendra Verma <shailendra.v@samsung.com>
> > > > ---
> > > >  drivers/i2c/busses/i2c-tegra.c |    4 ++++
> > > >  1 file changed, 4 insertions(+)
> > > 
> > > This will never happen. Any match in the OF table that would cause the
> > > ->probe() to occur has a valid .data pointer associated with it.
> > 
> > Theoretically you could (I think) bind that driver to a node with
> > 
> > 	compatible = "tegra-i2c";
> 
> That's not a valid compatible string and I don't think this could end up
> anywhere that would make the driver bind. Even if it did I think it'd be

Look at platform_match() in drivers/base/platform.c. If
of_driver_match_device fails it might still match based on
strcmp(pdev->name, drv->name).

Best regards
Uwe

-- 
Pengutronix e.K.                           | Uwe Kleine-König            |
Industrial Linux Solutions                 | http://www.pengutronix.de/  |