of_phy_find_device() is used to find the phy device associated with a device node. It is expected the node is for a PHY device, but in fact it could of been probed as a generic MDIO device. Ensure the device is a PHY before returning it.
Fixes: a9049e0c513c ("mdio: Add support for mdio drivers.") Reported-by: Aaro Koskinen <aaro.koski...@nokia.com> Reported-by: Olof Johansson <o...@lixom.net> Signed-off-by: Andrew Lunn <and...@lunn.ch> --- This is only 1/2 the fix. It will stop the NULL pointer dereference in the mutex code, but the Ethernet device probe is likely to return an error when it cannot find its PHY. --- drivers/of/of_mdio.c | 10 +++++++++- 1 file changed, 9 insertions(+), 1 deletion(-) diff --git a/drivers/of/of_mdio.c b/drivers/of/of_mdio.c index 86829f8064a6..b5aa004a24b6 100644 --- a/drivers/of/of_mdio.c +++ b/drivers/of/of_mdio.c @@ -256,11 +256,19 @@ static int of_phy_match(struct device *dev, void *phy_np) struct phy_device *of_phy_find_device(struct device_node *phy_np) { struct device *d; + struct mdio_device *mdiodev; + if (!phy_np) return NULL; d = bus_find_device(&mdio_bus_type, NULL, phy_np, of_phy_match); - return d ? to_phy_device(d) : NULL; + if (d) { + mdiodev = to_mdio_device(d); + if (mdiodev->flags & MDIO_DEVICE_FLAG_PHY) + return to_phy_device(d); + } + + return NULL; } EXPORT_SYMBOL(of_phy_find_device); -- 2.7.0