Re: [PATCH v2] mtd: fsl-quadspi: possible NULL dereference

From: Han Xu
Date: Tue Nov 17 2015 - 16:54:36 EST


On Mon, Nov 16, 2015 at 10:45:30AM -0800, Brian Norris wrote:
> It is theoretically possible to probe this driver without a matching
> device tree, so let's guard against this.
>
> Also, use the of_device_get_match_data() helper to make this a bit
> simpler.
>
> Coverity complained about this one.
>
> Signed-off-by: Brian Norris <computersforpeace@xxxxxxxxx>
> Cc: Han Xu <han.xu@xxxxxxxxxxxxx>
> ---
> v2:
> * missed a 'const' warning
> * s/reference/dereference in $subject
>
> drivers/mtd/spi-nor/fsl-quadspi.c | 8 ++++----
> 1 file changed, 4 insertions(+), 4 deletions(-)
>
> diff --git a/drivers/mtd/spi-nor/fsl-quadspi.c b/drivers/mtd/spi-nor/fsl-quadspi.c
> index cc3a70b9b020..916d6dd5b575 100644
> --- a/drivers/mtd/spi-nor/fsl-quadspi.c
> +++ b/drivers/mtd/spi-nor/fsl-quadspi.c
> @@ -269,7 +269,7 @@ struct fsl_qspi {
> struct clk *clk, *clk_en;
> struct device *dev;
> struct completion c;
> - struct fsl_qspi_devtype_data *devtype_data;
> + const struct fsl_qspi_devtype_data *devtype_data;
> u32 nor_size;
> u32 nor_num;
> u32 clk_rate;
> @@ -933,8 +933,6 @@ static int fsl_qspi_probe(struct platform_device *pdev)
> struct spi_nor *nor;
> struct mtd_info *mtd;
> int ret, i = 0;
> - const struct of_device_id *of_id =
> - of_match_device(fsl_qspi_dt_ids, &pdev->dev);
>
> q = devm_kzalloc(dev, sizeof(*q), GFP_KERNEL);
> if (!q)
> @@ -945,7 +943,9 @@ static int fsl_qspi_probe(struct platform_device *pdev)
> return -ENODEV;
>
> q->dev = dev;
> - q->devtype_data = (struct fsl_qspi_devtype_data *)of_id->data;
> + q->devtype_data = of_device_get_match_data(dev);
> + if (!q->devtype_data)
> + return -ENODEV;
> platform_set_drvdata(pdev, q);
>
> /* find the resources */
> --
> 2.6.0.rc2.230.g3dd15c0
>
Acked-by: Han xu <han.xu@xxxxxxxxxxxxx>
--
Best Regards,

Han "Allen" Xu

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