From 6d9f66ac7fec2a6ccd649e5909806dfe36f1fc25 Mon Sep 17 00:00:00 2001 From: Florian Fainelli Date: Wed, 8 Feb 2017 19:05:26 -0800 Subject: net: phy: Fix PHY module checks and NULL deref in phy_attach_direct() The Generic PHY drivers gets assigned after we checked that the current PHY driver is NULL, so we need to check a few things before we can safely dereference d->driver. This would be causing a NULL deference to occur when a system binds to the Generic PHY driver. Update phy_attach_direct() to do the following: - grab the driver module reference after we have assigned the Generic PHY drivers accordingly, and remember we came from the generic PHY path - update the error path to clean up the module reference in case the Generic PHY probe function fails - split the error path involving phy_detacht() to avoid double free/put since phy_detach() does all the clean up - finally, have phy_detach() drop the module reference count before we call device_release_driver() for the Generic PHY driver case Fixes: cafe8df8b9bc ("net: phy: Fix lack of reference count on PHY driver") Signed-off-by: Florian Fainelli Signed-off-by: David S. Miller --- drivers/net/phy/phy_device.c | 28 ++++++++++++++++++++-------- 1 file changed, 20 insertions(+), 8 deletions(-) (limited to 'drivers/net/phy') diff --git a/drivers/net/phy/phy_device.c b/drivers/net/phy/phy_device.c index 0d8f4d3847f6..8c8e15b8739d 100644 --- a/drivers/net/phy/phy_device.c +++ b/drivers/net/phy/phy_device.c @@ -908,6 +908,7 @@ int phy_attach_direct(struct net_device *dev, struct phy_device *phydev, struct module *ndev_owner = dev->dev.parent->driver->owner; struct mii_bus *bus = phydev->mdio.bus; struct device *d = &phydev->mdio.dev; + bool using_genphy = false; int err; /* For Ethernet device drivers that register their own MDIO bus, we @@ -920,11 +921,6 @@ int phy_attach_direct(struct net_device *dev, struct phy_device *phydev, return -EIO; } - if (!try_module_get(d->driver->owner)) { - dev_err(&dev->dev, "failed to get the device driver module\n"); - return -EIO; - } - get_device(d); /* Assume that if there is no driver, that it doesn't @@ -938,12 +934,22 @@ int phy_attach_direct(struct net_device *dev, struct phy_device *phydev, d->driver = &genphy_driver[GENPHY_DRV_1G].mdiodrv.driver; + using_genphy = true; + } + + if (!try_module_get(d->driver->owner)) { + dev_err(&dev->dev, "failed to get the device driver module\n"); + err = -EIO; + goto error_put_device; + } + + if (using_genphy) { err = d->driver->probe(d); if (err >= 0) err = device_bind_driver(d); if (err) - goto error; + goto error_module_put; } if (phydev->attached_dev) { @@ -980,9 +986,14 @@ int phy_attach_direct(struct net_device *dev, struct phy_device *phydev, return err; error: + /* phy_detach() does all of the cleanup below */ phy_detach(phydev); - put_device(d); + return err; + +error_module_put: module_put(d->driver->owner); +error_put_device: + put_device(d); if (ndev_owner != bus->owner) module_put(bus->owner); return err; @@ -1045,6 +1056,8 @@ void phy_detach(struct phy_device *phydev) phy_led_triggers_unregister(phydev); + module_put(phydev->mdio.dev.driver->owner); + /* If the device had no specific driver before (i.e. - it * was using the generic driver), we unbind the device * from the generic driver so that there's a chance a @@ -1065,7 +1078,6 @@ void phy_detach(struct phy_device *phydev) bus = phydev->mdio.bus; put_device(&phydev->mdio.dev); - module_put(phydev->mdio.dev.driver->owner); if (ndev_owner != bus->owner) module_put(bus->owner); } -- cgit v1.2.3 From bb1a619735b4660f21bce3e728b937640024b4ad Mon Sep 17 00:00:00 2001 From: Yendapally Reddy Dhananjaya Reddy Date: Wed, 8 Feb 2017 17:14:26 -0500 Subject: net: phy: Initialize mdio clock at probe function USB PHYs need the MDIO clock divisor enabled earlier to work. Initialize mdio clock divisor in probe function. The ext bus bit available in the same register will be used by mdio mux to enable external mdio. Signed-off-by: Yendapally Reddy Dhananjaya Reddy Fixes: ddc24ae1 ("net: phy: Broadcom iProc MDIO bus driver") Reviewed-by: Florian Fainelli Signed-off-by: Jon Mason Signed-off-by: David S. Miller --- drivers/net/phy/mdio-bcm-iproc.c | 6 ++---- 1 file changed, 2 insertions(+), 4 deletions(-) (limited to 'drivers/net/phy') diff --git a/drivers/net/phy/mdio-bcm-iproc.c b/drivers/net/phy/mdio-bcm-iproc.c index c0b4e65267af..46fe1ae919a3 100644 --- a/drivers/net/phy/mdio-bcm-iproc.c +++ b/drivers/net/phy/mdio-bcm-iproc.c @@ -81,8 +81,6 @@ static int iproc_mdio_read(struct mii_bus *bus, int phy_id, int reg) if (rc) return rc; - iproc_mdio_config_clk(priv->base); - /* Prepare the read operation */ cmd = (MII_DATA_TA_VAL << MII_DATA_TA_SHIFT) | (reg << MII_DATA_RA_SHIFT) | @@ -112,8 +110,6 @@ static int iproc_mdio_write(struct mii_bus *bus, int phy_id, if (rc) return rc; - iproc_mdio_config_clk(priv->base); - /* Prepare the write operation */ cmd = (MII_DATA_TA_VAL << MII_DATA_TA_SHIFT) | (reg << MII_DATA_RA_SHIFT) | @@ -163,6 +159,8 @@ static int iproc_mdio_probe(struct platform_device *pdev) bus->read = iproc_mdio_read; bus->write = iproc_mdio_write; + iproc_mdio_config_clk(priv->base); + rc = of_mdiobus_register(bus, pdev->dev.of_node); if (rc) { dev_err(&pdev->dev, "MDIO bus registration failed\n"); -- cgit v1.2.3