Re: [PATCH] mtd: nand: vf610_nfc: add NULL check on of_match_device() return value
From: Marek Vasut
Date: Mon Jul 17 2017 - 16:49:15 EST
On 07/17/2017 10:46 PM, Boris Brezillon wrote:
> Le Fri, 7 Jul 2017 01:59:26 -0500,
> "Gustavo A. R. Silva" <garsilva@xxxxxxxxxxxxxx> a Ãcrit :
>
>> Check return value from call to of_match_device()
>> in order to prevent a NULL pointer dereference.
>>
>> In case of NULL print error message and return -ENODEV
>>
>> Signed-off-by: Gustavo A. R. Silva <garsilva@xxxxxxxxxxxxxx>
>> ---
>> drivers/mtd/nand/vf610_nfc.c | 5 +++++
>> 1 file changed, 5 insertions(+)
>>
>> diff --git a/drivers/mtd/nand/vf610_nfc.c b/drivers/mtd/nand/vf610_nfc.c
>> index 744ab10..ca0ab96 100644
>> --- a/drivers/mtd/nand/vf610_nfc.c
>> +++ b/drivers/mtd/nand/vf610_nfc.c
>> @@ -674,6 +674,11 @@ static int vf610_nfc_probe(struct platform_device *pdev)
>> }
>>
>> of_id = of_match_device(vf610_nfc_dt_ids, &pdev->dev);
>> + if (!of_id) {
>> + dev_err(&pdev->dev, "Failed to match device!\n");
>> + return -ENODEV;
>> + }
>> +
>
> While this check is functionally correct, this case cannot happen,
> because this is DT-only driver, and without a valid match in
> vf610_nfc_dt_ids the dev wouldn't have been probed in the first place.
>
> I'll let Stefan decide whether he wants it or not, but I see no real
> reason for this extra check.
So how did you trigger the issue in the first place ?
--
Best regards,
Marek Vasut