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authorRussell King <rmk+kernel@arm.linux.org.uk>2015-09-24 20:35:52 +0100
committerDavid S. Miller <davem@davemloft.net>2015-09-24 23:04:52 -0700
commita136442131443d929d2d8d243157824de4dfbae8 (patch)
tree1a6e439b37d344366bd275e157ac11b867e89f36 /drivers/net/phy
parent17a10c9215b39a5ea8faeb241759c1aee6553919 (diff)
downloadlinux-linaro-stable-a136442131443d929d2d8d243157824de4dfbae8.tar.gz
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>
Diffstat (limited to 'drivers/net/phy')
-rw-r--r--drivers/net/phy/mdio-mux.c19
-rw-r--r--drivers/net/phy/mdio_bus.c4
2 files changed, 16 insertions, 7 deletions
diff --git a/drivers/net/phy/mdio-mux.c b/drivers/net/phy/mdio-mux.c
index 4d4d25efc1e1..280c7c311f72 100644
--- a/drivers/net/phy/mdio-mux.c
+++ b/drivers/net/phy/mdio-mux.c
@@ -113,18 +113,18 @@ int mdio_mux_init(struct device *dev,
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 @@ int mdio_mux_init(struct device *dev,
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 @@ void mdio_mux_uninit(void *mux_handle)
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);
diff --git a/drivers/net/phy/mdio_bus.c b/drivers/net/phy/mdio_bus.c
index 02a4615b65f8..67553e13bd36 100644
--- a/drivers/net/phy/mdio_bus.c
+++ b/drivers/net/phy/mdio_bus.c
@@ -167,7 +167,9 @@ static int of_mdio_bus_match(struct device *dev, const void *mdio_bus_np)
* of_mdio_find_bus - Given an mii_bus node, find the mii_bus.
* @mdio_bus_np: Pointer to the mii_bus.
*
- * Returns a pointer to the mii_bus, or NULL if none found.
+ * Returns a reference to the mii_bus, or NULL if none found. The
+ * embedded struct device will have its reference count incremented,
+ * and this must be put once the bus is finished with.
*
* Because the association of a device_node and mii_bus is made via
* of_mdiobus_register(), the mii_bus cannot be found before it is