[PATCH 6.0 0705/1073] usb: roles: fix of node refcount leak in usb_role_switch_is_parent()

Greg Kroah-Hartman
2022-12-28T16:23:35Z

From: Yang Yingliang <yangyingliang@huawei.com>

[ Upstream commit 1ab30c610630da5391a373cddb8a065bf4c4bc01 ]

I got the following report while doing device(mt6370-tcpc) load
test with CONFIG_OF_UNITTEST and CONFIG_OF_DYNAMIC enabled:

OF: ERROR: memory leak, expected refcount 1 instead of 2,
of_node_get()/of_node_put() unbalanced - destroy cset entry:
attach overlay node /i2c/pmic@34

The 'parent' returned by fwnode_get_parent() with refcount incremented.
it needs be put after using.

Fixes: 6fadd72943b8 ("usb: roles: get usb-role-switch from parent")
Reviewed-by: Heikki Krogerus <heikki.krogerus@linux.intel.com>
Signed-off-by: Yang Yingliang <yangyingliang@huawei.com>
Link: https://lore.kernel.org/r/20221122111226.251588-1-yangyingliang@huawei.com
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Signed-off-by: Sasha Levin <sashal@kernel.org>
---
drivers/usb/roles/class.c | 5 ++++-
1 file changed, 4 insertions(+), 1 deletion(-)

diff --git a/drivers/usb/roles/class.c b/drivers/usb/roles/class.c
index dfaed7eee94f..32e6d19f7011 100644
--- a/drivers/usb/roles/class.c
+++ b/drivers/usb/roles/class.c
@@ -106,10 +106,13 @@ usb_role_switch_is_parent(struct fwnode_handle *fwnode)
struct fwnode_handle *parent = fwnode_get_parent(fwnode);
struct device *dev;

- if (!parent || !fwnode_property_present(parent, "usb-role-switch"))
+ if (!fwnode_property_present(parent, "usb-role-switch")) {
+ fwnode_handle_put(parent);
return NULL;
+ }

dev = class_find_device_by_fwnode(role_class, parent);
+ fwnode_handle_put(parent);
return dev ? to_role_switch(dev) : ERR_PTR(-EPROBE_DEFER);
}

--
2.35.1