RDMA/netdev: Fix netlink support in IPoIB

IPoIB netlink support was broken by the below commit since integrating
the rdma_netdev support relies on an allocation flow for netdevs that
was controlled by the ipoib driver while netdev's rtnl_newlink
implementation assumes that the netdev will be allocated by netlink.
Such situation leads to crash in __ipoib_device_add, once trying to
reuse netlink device.

This patch fixes the kernel oops for both mlx4 and mlx5
devices triggered by the following command:

Fixes: cd565b4b51e5 ("IB/IPoIB: Support acceleration options callbacks")
Signed-off-by: Denis Drozdov <denisd@mellanox.com>
Signed-off-by: Jason Gunthorpe <jgg@mellanox.com>
Signed-off-by: Feras Daoud <ferasda@mellanox.com>
Signed-off-by: Saeed Mahameed <saeedm@mellanox.com>

1 files changed, 21 insertions, 2 deletions

diff --git a/drivers/infiniband/ulp/ipoib/ipoib_netlink.c b/drivers/infiniband/ulp/ipoib/ipoib_netlink.c
index d4d553a51fa9..38c984d16996 100644
--- a/drivers/infiniband/ulp/ipoib/ipoib_netlink.c
+++ b/drivers/infiniband/ulp/ipoib/ipoib_netlink.c
@@ -122,12 +122,26 @@ static int ipoib_new_child_link(struct net *src_net, struct net_device *dev,
 	} else
 		child_pkey  = nla_get_u16(data[IFLA_IPOIB_PKEY]);
 
+	err = ipoib_intf_init(ppriv->ca, ppriv->port, dev->name, dev);
+	if (err) {
+		ipoib_warn(ppriv, "failed to initialize pkey device\n");
+		return err;
+	}
+
 	err = __ipoib_vlan_add(ppriv, ipoib_priv(dev),
 			       child_pkey, IPOIB_RTNL_CHILD);
+	if (err)
+		return err;
 
-	if (!err && data)
+	if (data) {
 		err = ipoib_changelink(dev, tb, data, extack);
-	return err;
+		if (err) {
+			unregister_netdevice(dev);
+			return err;
+		}
+	}
+
+	return 0;
 }
 
 static size_t ipoib_get_size(const struct net_device *dev)
@@ -149,6 +163,11 @@ static struct rtnl_link_ops ipoib_link_ops __read_mostly = {
 	.fill_info	= ipoib_fill_info,
 };
 
+struct rtnl_link_ops *ipoib_get_link_ops(void)
+{
+	return &ipoib_link_ops;
+}
+
 int __init ipoib_netlink_init(void)
 {
 	return rtnl_link_register(&ipoib_link_ops);