On Mon, 12 Dec 2016 08:30:04 +0530 Arvind Yadav <[email protected]> wrote:
> Here, If devm_ioremap will fail. It will return NULL. > Kernel can run into a NULL-pointer dereference. > > Signed-off-by: Arvind Yadav <[email protected]> > --- > drivers/mtd/devices/docg3.c | 7 ++++++- > 1 file changed, 6 insertions(+), 1 deletion(-) > > diff --git a/drivers/mtd/devices/docg3.c b/drivers/mtd/devices/docg3.c > index b833e6c..ffe3db0 100644 > --- a/drivers/mtd/devices/docg3.c > +++ b/drivers/mtd/devices/docg3.c > @@ -2083,9 +2083,14 @@ 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) { > + dev_err(dev, "failed to map I/O memory\n"); > + return ret; > + } > + > cascade = devm_kzalloc(dev, sizeof(*cascade) * DOC_MAX_NBFLOORS, > GFP_KERNEL); > if (!cascade) How about going even further and doing the following? This way you can drop the test on rres (it's done for you in devm_ioremap_resource()), and you can directly return the error returned by devm_ioremap_resource(). --->8--- diff --git a/drivers/mtd/devices/docg3.c b/drivers/mtd/devices/docg3.c index b833e6cc684c..c59b91734344 100644 --- a/drivers/mtd/devices/docg3.c +++ b/drivers/mtd/devices/docg3.c @@ -2077,13 +2077,10 @@ static int __init docg3_probe(struct platform_device *pdev) int ret, floor; struct docg3_cascade *cascade; - ret = -ENXIO; ress = platform_get_resource(pdev, IORESOURCE_MEM, 0); - if (!ress) { - dev_err(dev, "No I/O memory resource defined\n"); - return ret; - } - base = devm_ioremap(dev, ress->start, DOC_IOSPACE_SIZE); + base = devm_ioremap_resource(dev, ress); + if (IS_ERR(base)) + return PTR_ERR(base); ret = -ENOMEM; cascade = devm_kzalloc(dev, sizeof(*cascade) * DOC_MAX_NBFLOORS,
