Re: [PATCH] I2c: busses - Fix possible NULL derefrence.

From: Uwe Kleine-König
Date: Mon Jan 30 2017 - 06:16:51 EST


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@xxxxxxxxxxx>
> > > > ---
> > > > 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

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