From e809a683c5daca37e39b408d4393b188a1915d85 Mon Sep 17 00:00:00 2001 From: Andrew Lunn Date: Mon, 9 Jan 2023 16:30:44 +0100 Subject: [PATCH] net: mdio: C22 is now optional, EOPNOTSUPP if not provided [ Upstream commit b063b1924fd9bf0bc157cf644764dc2151d04ccc ] When performing a C22 operation, check that the bus driver actually provides the methods, and return -EOPNOTSUPP if not. C45 only busses do exist, and in future their C22 methods will be NULL. Signed-off-by: Andrew Lunn Signed-off-by: Michael Walle Signed-off-by: Jakub Kicinski Stable-dep-of: 0e629694126c ("net/mdiobus: Fix potential out-of-bounds read/write access") Signed-off-by: Sasha Levin --- drivers/net/phy/mdio_bus.c | 10 ++++++++-- 1 file changed, 8 insertions(+), 2 deletions(-) diff --git a/drivers/net/phy/mdio_bus.c b/drivers/net/phy/mdio_bus.c index 16e021b477f06..ee5fc73cbe075 100644 --- a/drivers/net/phy/mdio_bus.c +++ b/drivers/net/phy/mdio_bus.c @@ -764,7 +764,10 @@ int __mdiobus_read(struct mii_bus *bus, int addr, u32 regnum) lockdep_assert_held_once(&bus->mdio_lock); - retval = bus->read(bus, addr, regnum); + if (bus->read) + retval = bus->read(bus, addr, regnum); + else + retval = -EOPNOTSUPP; trace_mdio_access(bus, 1, addr, regnum, retval, retval); mdiobus_stats_acct(&bus->stats[addr], true, retval); @@ -790,7 +793,10 @@ int __mdiobus_write(struct mii_bus *bus, int addr, u32 regnum, u16 val) lockdep_assert_held_once(&bus->mdio_lock); - err = bus->write(bus, addr, regnum, val); + if (bus->write) + err = bus->write(bus, addr, regnum, val); + else + err = -EOPNOTSUPP; trace_mdio_access(bus, 0, addr, regnum, val, err); mdiobus_stats_acct(&bus->stats[addr], false, err); -- 2.47.3