phy: fix of_mdio_find_bus() device refcount leak
of_mdio_find_bus() leaks a struct device refcount, caused by using
class_find_device() and not realising that the device reference has
its refcount incremented:
* Note, you will need to drop the reference with put_device() after use.
...
while ((dev = class_dev_iter_next(&iter))) {
if (match(dev, data)) {
get_device(dev);
break;
}
Update the comment, and arrange for the phy code to drop this refcount
when disposing of a reference to it.
Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>
Signed-off-by: David S. Miller <davem@davemloft.net>
diff --git a/drivers/net/phy/mdio-mux.c b/drivers/net/phy/mdio-mux.c
index 4d4d25e..280c7c3 100644
--- a/drivers/net/phy/mdio-mux.c
+++ b/drivers/net/phy/mdio-mux.c
@@ -113,18 +113,18 @@
if (!parent_bus_node)
return -ENODEV;
- parent_bus = of_mdio_find_bus(parent_bus_node);
- if (parent_bus == NULL) {
- ret_val = -EPROBE_DEFER;
- goto err_parent_bus;
- }
-
pb = devm_kzalloc(dev, sizeof(*pb), GFP_KERNEL);
if (pb == NULL) {
ret_val = -ENOMEM;
goto err_parent_bus;
}
+ parent_bus = of_mdio_find_bus(parent_bus_node);
+ if (parent_bus == NULL) {
+ ret_val = -EPROBE_DEFER;
+ goto err_parent_bus;
+ }
+
pb->switch_data = data;
pb->switch_fn = switch_fn;
pb->current_child = -1;
@@ -173,6 +173,10 @@
dev_info(dev, "Version " DRV_VERSION "\n");
return 0;
}
+
+ /* balance the reference of_mdio_find_bus() took */
+ put_device(&pb->mii_bus->dev);
+
err_parent_bus:
of_node_put(parent_bus_node);
return ret_val;
@@ -189,6 +193,9 @@
mdiobus_free(cb->mii_bus);
cb = cb->next;
}
+
+ /* balance the reference of_mdio_find_bus() in mdio_mux_init() took */
+ put_device(&pb->mii_bus->dev);
}
EXPORT_SYMBOL_GPL(mdio_mux_uninit);