diff --git a/drivers/net/phy/mdio_bus.c b/drivers/net/phy/mdio_bus.c
index 103998969d44..e02706b7cc1e 100644
--- a/drivers/net/phy/mdio_bus.c
+++ b/drivers/net/phy/mdio_bus.c
@@ -946,6 +946,9 @@ int __mdiobus_c45_read(struct mii_bus *bus, int addr, int devad, u32 regnum)
 
 	lockdep_assert_held_once(&bus->mdio_lock);
 
+	if (addr >= PHY_MAX_ADDR)
+		return -ENXIO;
+
 	if (bus->read_c45)
 		retval = bus->read_c45(bus, addr, devad, regnum);
 	else
@@ -977,6 +980,9 @@ int __mdiobus_c45_write(struct mii_bus *bus, int addr, int devad, u32 regnum,
 
 	lockdep_assert_held_once(&bus->mdio_lock);
 
+	if (addr >= PHY_MAX_ADDR)
+		return -ENXIO;
+
 	if (bus->write_c45)
 		err = bus->write_c45(bus, addr, devad, regnum, val);
 	else