Date: Fri, 7 Jul 2017 11:25:51 +0200
From: Thierry Reding <thierry.reding@gmail.com>
To: "Gustavo A. R. Silva" <garsilva@embeddedor.com>
Cc: David Airlie <airlied@linux.ie>,
        Jonathan Hunter <jonathanh@nvidia.com>,
        dri-devel@lists.freedesktop.org, linux-tegra@vger.kernel.org,
        linux-kernel@vger.kernel.org
Subject: Re: [PATCH] drm/tegra: vic: add NULL check on of_match_device()
 return value
Message-ID: <20170707092551.GB15652@ulmo.fritz.box>
References: <20170707061626.GA14016@embeddedgus>
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On Fri, Jul 07, 2017 at 01:16:26AM -0500, Gustavo A. R. Silva wrote:
> Check return value from call to of_match_device()
> in order to prevent a NULL pointer dereference.
>=20
> In case of NULL print error message and return.
>=20
> Signed-off-by: Gustavo A. R. Silva <garsilva@embeddedor.com>
> ---
>  drivers/gpu/drm/tegra/vic.c | 5 +++++
>  1 file changed, 5 insertions(+)
>=20
> diff --git a/drivers/gpu/drm/tegra/vic.c b/drivers/gpu/drm/tegra/vic.c
> index 47cb1aa..7e11825 100644
> --- a/drivers/gpu/drm/tegra/vic.c
> +++ b/drivers/gpu/drm/tegra/vic.c
> @@ -283,6 +283,11 @@ static int vic_probe(struct platform_device *pdev)
>  	int err;
> =20
>  	match =3D of_match_device(vic_match, dev);
> +	if (!match) {
> +		dev_err(&pdev->dev, "failed to match device\n");
> +		return -ENODEV;
> +	}

Someone would have to go to great lengths to trigger this condition,
might as well let it crash as a warning that they've done something
wrong.

Thierry

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