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

From: arvind Yadav
Date: Sun Dec 11 2016 - 21:59:34 EST

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


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.


cascade = devm_kzalloc(dev, sizeof(*cascade) * DOC_MAX_NBFLOORS,
if (!cascade)