Re: [PATCH linux-next 1/4] infiniband/ipoib: fix possible NULL pointer dereference in ipoib_get_iflink

Erez Shitrit
2015-04-14T16:30:03Z

On Tue, Apr 14, 2015 at 6:20 PM, Honggang Li <honli@redhat.com> wrote:
>

[...]

Hi,

> diff --git a/drivers/infiniband/ulp/ipoib/ipoib_main.c b/drivers/infiniband/ulp/ipoib/ipoib_main.c
> index 657b89b..11ea6e2 100644
> --- a/drivers/infiniband/ulp/ipoib/ipoib_main.c
> +++ b/drivers/infiniband/ulp/ipoib/ipoib_main.c
> @@ -846,7 +846,10 @@ static int ipoib_get_iflink(const struct net_device *dev)
> {
> struct ipoib_dev_priv *priv = netdev_priv(dev);
>
> - return priv->parent->ifindex;
> + if (priv && priv->parent)
> + return priv->parent->ifindex;
> + else
> + return 0;
This will make parent interface to return 0 instead of its own ifindex.
I would suggest write something like that:

+ /* parent interface */
+ if (!test_bit(IPOIB_FLAG_SUBINTERFACE, &priv->flags))
+ return dev->ifindex;
+
+ /* child/vlan interface */
+ if (!priv->parent)
+ return -1;
+
return priv->parent->ifindex;

Thanks,
Erez.

> }
>
> static u32 ipoib_addr_hash(struct ipoib_neigh_hash *htbl, u8 *daddr)
> --
> 1.8.3.1
>