From 54a25a1e04af2e69d45bb757d40dccf22354a170 Mon Sep 17 00:00:00 2001
From: Joe Hattori <joe@pf.is.s.u-tokyo.ac.jp>
Date: Tue, 6 Aug 2024 10:13:27 +0900
Subject: [PATCH] net: dsa: bcm_sf2: Fix a possible memory leak in
 bcm_sf2_mdio_register()

[ Upstream commit e3862093ee93fcfbdadcb7957f5f8974fffa806a ]

bcm_sf2_mdio_register() calls of_phy_find_device() and then
phy_device_remove() in a loop to remove existing PHY devices.
of_phy_find_device() eventually calls bus_find_device(), which calls
get_device() on the returned struct device * to increment the refcount.
The current implementation does not decrement the refcount, which causes
memory leak.

This commit adds the missing phy_device_free() call to decrement the
refcount via put_device() to balance the refcount.

Fixes: 771089c2a485 ("net: dsa: bcm_sf2: Ensure that MDIO diversion is used")
Signed-off-by: Joe Hattori <joe@pf.is.s.u-tokyo.ac.jp>
Tested-by: Florian Fainelli <florian.fainelli@broadcom.com>
Reviewed-by: Florian Fainelli <florian.fainelli@broadcom.com>
Link: https://patch.msgid.link/20240806011327.3817861-1-joe@pf.is.s.u-tokyo.ac.jp
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
Signed-off-by: Sasha Levin <sashal@kernel.org>
---
 drivers/net/dsa/bcm_sf2.c | 4 +++-
 1 file changed, 3 insertions(+), 1 deletion(-)

diff --git a/drivers/net/dsa/bcm_sf2.c b/drivers/net/dsa/bcm_sf2.c
index 1fa392aee52de0..f259b0add5b2e1 100644
--- a/drivers/net/dsa/bcm_sf2.c
+++ b/drivers/net/dsa/bcm_sf2.c
@@ -638,8 +638,10 @@ static int bcm_sf2_mdio_register(struct dsa_switch *ds)
 			of_remove_property(child, prop);
 
 		phydev = of_phy_find_device(child);
-		if (phydev)
+		if (phydev) {
 			phy_device_remove(phydev);
+			phy_device_free(phydev);
+		}
 	}
 
 	err = mdiobus_register(priv->slave_mii_bus);