net: emaclite: Add error handling for of_address_to_resource()

check the return value of of_address_to_resource() and also add
missing of_node_put() for np and npp nodes.

Fixes: e0a3bc6 ("net: emaclite: Support multiple phys connected to one MDIO bus")
Addresses-Coverity: Event check_return value.
Signed-off-by: Shravya Kumbham <[email protected]>
Signed-off-by: Radhey Shyam Pandey <[email protected]>
Signed-off-by: Paolo Abeni <[email protected]>

Author: Shravya Kumbham

drivers/net/ethernet/xilinx/xilinx_emaclite.c

@@ -823,10 +823,10 @@ static int xemaclite_mdio_write(struct mii_bus *bus, int phy_id, int reg,
 static int xemaclite_mdio_setup(struct net_local *lp, struct device *dev)
 {
 	struct mii_bus *bus;
-	int rc;
 	struct resource res;
 	struct device_node *np = of_get_parent(lp->phy_node);
 	struct device_node *npp;
+	int rc, ret;
 
 	/* Don't register the MDIO bus if the phy_node or its parent node
 	 * can't be found.
@@ -836,8 +836,14 @@ static int xemaclite_mdio_setup(struct net_local *lp, struct device *dev)
 		return -ENODEV;
 	}
 	npp = of_get_parent(np);
-
-	of_address_to_resource(npp, 0, &res);
+	ret = of_address_to_resource(npp, 0, &res);
+	of_node_put(npp);
+	if (ret) {
+		dev_err(dev, "%s resource error!\n",
+			dev->of_node->full_name);
+		of_node_put(np);
+		return ret;
+	}
 	if (lp->ndev->mem_start != res.start) {
 		struct phy_device *phydev;
 		phydev = of_phy_find_device(lp->phy_node);
@@ -846,6 +852,7 @@ static int xemaclite_mdio_setup(struct net_local *lp, struct device *dev)
 				 "MDIO of the phy is not registered yet\n");
 		else
 			put_device(&phydev->mdio.dev);
+		of_node_put(np);
 		return 0;
 	}
 
@@ -858,6 +865,7 @@ static int xemaclite_mdio_setup(struct net_local *lp, struct device *dev)
 	bus = mdiobus_alloc();
 	if (!bus) {
 		dev_err(dev, "Failed to allocate mdiobus\n");
+		of_node_put(np);
 		return -ENOMEM;
 	}
 
@@ -870,6 +878,7 @@ static int xemaclite_mdio_setup(struct net_local *lp, struct device *dev)
 	bus->parent = dev;
 
 	rc = of_mdiobus_register(bus, np);
+	of_node_put(np);
 	if (rc) {
 		dev_err(dev, "Failed to register mdio bus.\n");
 		goto err_register;