net: dsa: bcm_sf2: Fix possible memory leak in bcm_sf2_mdio_register()
authorJinjie Ruan <ruanjinjie@huawei.com>
Wed, 11 Oct 2023 03:24:19 +0000 (11:24 +0800)
committerGreg Kroah-Hartman <gregkh@linuxfoundation.org>
Wed, 25 Oct 2023 10:03:07 +0000 (12:03 +0200)
commit3065fabd17c52de10e6bfb56719c66fdfe309a24
treec1b9a8e917246c204858c820364696b162750456
parent9c3d276fa866281cb4ec7ea4ccf2bd00fdb2f0b2
net: dsa: bcm_sf2: Fix possible memory leak in bcm_sf2_mdio_register()

commit 61b40cefe51af005c72dbdcf975a3d166c6e6406 upstream.

In bcm_sf2_mdio_register(), the class_find_device() will call get_device()
to increment reference count for priv->master_mii_bus->dev if
of_mdio_find_bus() succeeds. If mdiobus_alloc() or mdiobus_register()
fails, it will call get_device() twice without decrement reference count
for the device. And it is the same if bcm_sf2_mdio_register() succeeds but
fails in bcm_sf2_sw_probe(), or if bcm_sf2_sw_probe() succeeds. If the
reference count has not decremented to zero, the dev related resource will
not be freed.

So remove the get_device() in bcm_sf2_mdio_register(), and call
put_device() if mdiobus_alloc() or mdiobus_register() fails and in
bcm_sf2_mdio_unregister() to solve the issue.

And as Simon suggested, unwind from errors for bcm_sf2_mdio_register() and
just return 0 if it succeeds to make it cleaner.

Fixes: 461cd1b03e32 ("net: dsa: bcm_sf2: Register our slave MDIO bus")
Signed-off-by: Jinjie Ruan <ruanjinjie@huawei.com>
Suggested-by: Simon Horman <horms@kernel.org>
Reviewed-by: Simon Horman <horms@kernel.org>
Reviewed-by: Florian Fainelli <florian.fainelli@broadcom.com>
Link: https://lore.kernel.org/r/20231011032419.2423290-1-ruanjinjie@huawei.com
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
drivers/net/dsa/bcm_sf2.c