Re: [V1] mtd: devices: docg3:- Handle return value of devm_ioremap.

[arvind Yadav]

Yes, We are returning -ENOMEM, ret is initialized to -ENOMEM.
As per your concern, I have added dev_err failure message.

Thanks
-Arvind

On Monday 12 December 2016 12:45 AM, Marek Vasut wrote:
> On 12/11/2016 07:01 PM, Arvind Yadav wrote:
> > Here, If devm_ioremap will fail. It will return NULL.
> > Kernel can run into a NULL-pointer dereference.
> >
> > Signed-off-by: Arvind Yadav <arvind.yadav.cs@xxxxxxxxx>
> > ---
> >   drivers/mtd/devices/docg3.c | 5 ++++-
> >   1 file changed, 4 insertions(+), 1 deletion(-)
> >
> > diff --git a/drivers/mtd/devices/docg3.c b/drivers/mtd/devices/docg3.c
> > index b833e6c..013b5b9 100644
> > --- a/drivers/mtd/devices/docg3.c
> > +++ b/drivers/mtd/devices/docg3.c
> > @@ -2083,9 +2083,12 @@ static int __init docg3_probe(struct platform_device *pdev)
> >   		dev_err(dev, "No I/O memory resource defined\n");
> >   		return ret;
> >   	}
> > -	base = devm_ioremap(dev, ress->start, DOC_IOSPACE_SIZE);
> >   
> >   	ret = -ENOMEM;
> > +	base = devm_ioremap(dev, ress->start, DOC_IOSPACE_SIZE);
> > +	if (!base)
> > +		return ret;
> I think return -ENOMEM right away won't hurt here. Also, dev_err()
> explaining the failure would be nice to add.
>
> Thanks!
>
> >   	cascade = devm_kzalloc(dev, sizeof(*cascade) * DOC_MAX_NBFLOORS,
> >   			       GFP_KERNEL);
> >   	if (!cascade)