From 38c9d4f8e62e3c728e5285e4e6cc82e898ddda71 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 fdf8221f46fa..e5c25beae21e 100644 --- a/drivers/net/phy/mdio_bus.c +++ b/drivers/net/phy/mdio_bus.c @@ -565,7 +565,10 @@ int __mdiobus_read(struct mii_bus *bus, int addr, u32 regnum) WARN_ON_ONCE(!mutex_is_locked(&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); @@ -590,7 +593,10 @@ int __mdiobus_write(struct mii_bus *bus, int addr, u32 regnum, u16 val) WARN_ON_ONCE(!mutex_is_locked(&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);