In the Linux kernel, the following vulnerability has been resolved:

net: mdio: fix unbalanced fwnode reference count in mdio_device_release()

There is warning report about of_node refcount leak
while probing mdio device:

OF: ERROR: memory leak, expected refcount 1 instead of 2,
of_node_get()/of_node_put() unbalanced - destroy cset entry:
attach overlay node /spi/soc@0/mdio@710700c0/ethernet@4

In of_mdiobus_register_device(), we increase fwnode refcount
by fwnode_handle_get() before associating the of_node with
mdio device, but it has never been decreased in normal path.
Since that, in mdio_device_release(), it needs to call
fwnode_handle_put() in addition instead of calling kfree()
directly.

After above, just calling mdio_device_free() in the error handle
path of of_mdiobus_register_device() is enough to keep the
refcount balanced.

kernel.org https://git.kernel.org/stable/c/16854177745a5648f8ec322353b432e18460f43a [No types assigned]

kernel.org https://git.kernel.org/stable/c/a5c6de1a6656b8cc6bce7cb3d9874dd7df4968c3 [No types assigned]

kernel.org https://git.kernel.org/stable/c/cb37617687f2bfa5b675df7779f869147c9002bd [No types assigned]