net: mdio_bus: validate "addr" for mdiobus_is_registered_device()

mdiobus_is_registered_device() doesn't checking that "addr" was valid
before dereferencing bus->mdio_map[]. Extract the code that checks
this from mdiobus_get_phy(), and use it here as well.

Signed-off-by: Russell King (Oracle) <rmk+kernel@armlinux.org.uk>
Reviewed-by: Andrew Lunn <andrew@lunn.ch>
Link: https://lore.kernel.org/r/E1qNxvu-00111m-1V@rmk-PC.armlinux.org.uk
Signed-off-by: Jakub Kicinski <kuba@kernel.org>

diff --git a/drivers/net/phy/mdio_bus.c b/drivers/net/phy/mdio_bus.c
index bc04048de2faf04e6da60716c7d83c5963d29463..25dcaa49ab8be9d2ea75ae46a38a4bf3b69dca3a 100644 (file)
--- a/drivers/net/phy/mdio_bus.c
+++ b/drivers/net/phy/mdio_bus.c
@@ -107,16 +107,21 @@ int mdiobus_unregister_device(struct mdio_device *mdiodev)
 }
 EXPORT_SYMBOL(mdiobus_unregister_device);
 
-struct phy_device *mdiobus_get_phy(struct mii_bus *bus, int addr)
+static struct mdio_device *mdiobus_find_device(struct mii_bus *bus, int addr)
 {
        bool addr_valid = addr >= 0 && addr < ARRAY_SIZE(bus->mdio_map);
-       struct mdio_device *mdiodev;
 
        if (WARN_ONCE(!addr_valid, "addr %d out of range\n", addr))
                return NULL;
 
-       mdiodev = bus->mdio_map[addr];
+       return bus->mdio_map[addr];
+}
 
+struct phy_device *mdiobus_get_phy(struct mii_bus *bus, int addr)
+{
+       struct mdio_device *mdiodev;
+
+       mdiodev = mdiobus_find_device(bus, addr);
        if (!mdiodev)
                return NULL;
 
@@ -129,7 +134,7 @@ EXPORT_SYMBOL(mdiobus_get_phy);
 
 bool mdiobus_is_registered_device(struct mii_bus *bus, int addr)
 {
-       return bus->mdio_map[addr];
+       return mdiobus_find_device(bus, addr) != NULL;
 }
 EXPORT_SYMBOL(mdiobus_is_registered_device);