From: Andrew Lunn Date: Mon, 9 Jan 2023 15:30:44 +0000 (+0100) Subject: net: mdio: C22 is now optional, EOPNOTSUPP if not provided X-Git-Tag: v5.10.239~224 X-Git-Url: http://git.ipfire.org/gitweb.cgi?a=commitdiff_plain;h=72e9c8aa595b3ec65488099ed0c541c7cae4bfd9;p=thirdparty%2Fkernel%2Fstable.git 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 --- diff --git a/drivers/net/phy/mdio_bus.c b/drivers/net/phy/mdio_bus.c index e9303be486556..743a63eca7840 100644 --- a/drivers/net/phy/mdio_bus.c +++ b/drivers/net/phy/mdio_bus.c @@ -754,7 +754,10 @@ 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); mdiobus_stats_acct(&bus->stats[addr], true, retval); @@ -780,7 +783,10 @@ 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); mdiobus_stats_acct(&bus->stats[addr], false, err);