diff options
| author | Russell King <rmk+kernel@arm.linux.org.uk> | 2015-09-24 22:35:52 +0300 |
|---|---|---|
| committer | David S. Miller <davem@davemloft.net> | 2015-09-25 09:04:52 +0300 |
| commit | a136442131443d929d2d8d243157824de4dfbae8 (patch) | |
| tree | 1a6e439b37d344366bd275e157ac11b867e89f36 | |
| parent | 17a10c9215b39a5ea8faeb241759c1aee6553919 (diff) | |
| download | linux-a136442131443d929d2d8d243157824de4dfbae8.tar.xz | |
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>
| -rw-r--r-- | drivers/net/phy/mdio-mux.c | 19 | ||||
| -rw-r--r-- | drivers/net/phy/mdio_bus.c | 4 |
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 |