net: dsa: fix of_mdio_find_bus() device refcount leak

[linux-drm-fsl-dcu.git] / net / dsa / dsa.c

diff --git a/net/dsa/dsa.c b/net/dsa/dsa.c
index 76e3800765f881c554e93385c85f965cc96f611c..bf4ba15fb780e96ed77858c68a5d724a065962d6 100644 (file)
--- a/net/dsa/dsa.c
+++ b/net/dsa/dsa.c
@@ -634,6 +634,10 @@ static void dsa_of_free_platform_data(struct dsa_platform_data *pd)
                        port_index++;
                }
                kfree(pd->chip[i].rtable);
+
+               /* Drop our reference to the MDIO bus device */
+               if (pd->chip[i].host_dev)
+                       put_device(pd->chip[i].host_dev);
        }
        kfree(pd->chip);
 }
@@ -661,16 +665,22 @@ static int dsa_of_probe(struct device *dev)
                return -EPROBE_DEFER;
 
        ethernet = of_parse_phandle(np, "dsa,ethernet", 0);
-       if (!ethernet)
-               return -EINVAL;
+       if (!ethernet) {
+               ret = -EINVAL;
+               goto out_put_mdio;
+       }
 
        ethernet_dev = of_find_net_device_by_node(ethernet);
-       if (!ethernet_dev)
-               return -EPROBE_DEFER;
+       if (!ethernet_dev) {
+               ret = -EPROBE_DEFER;
+               goto out_put_mdio;
+       }
 
        pd = kzalloc(sizeof(*pd), GFP_KERNEL);
-       if (!pd)
-               return -ENOMEM;
+       if (!pd) {
+               ret = -ENOMEM;
+               goto out_put_mdio;
+       }
 
        dev->platform_data = pd;
        pd->of_netdev = ethernet_dev;
@@ -691,7 +701,9 @@ static int dsa_of_probe(struct device *dev)
                cd = &pd->chip[chip_index];
 
                cd->of_node = child;
-               cd->host_dev = &mdio_bus->dev;
+
+               /* When assigning the host device, increment its refcount */
+               cd->host_dev = get_device(&mdio_bus->dev);
 
                sw_addr = of_get_property(child, "reg", NULL);
                if (!sw_addr)
@@ -711,6 +723,12 @@ static int dsa_of_probe(struct device *dev)
                                ret = -EPROBE_DEFER;
                                goto out_free_chip;
                        }
+
+                       /* Drop the mdio_bus device ref, replacing the host
+                        * device with the mdio_bus_switch device, keeping
+                        * the refcount from of_mdio_find_bus() above.
+                        */
+                       put_device(cd->host_dev);
                        cd->host_dev = &mdio_bus_switch->dev;
                }
 
@@ -744,6 +762,10 @@ static int dsa_of_probe(struct device *dev)
                }
        }
 
+       /* The individual chips hold their own refcount on the mdio bus,
+        * so drop ours */
+       put_device(&mdio_bus->dev);
+
        return 0;
 
 out_free_chip:
@@ -751,6 +773,8 @@ out_free_chip:
 out_free:
        kfree(pd);
        dev->platform_data = NULL;
+out_put_mdio:
+       put_device(&mdio_bus->dev);
        return ret;
 }