Hello Florian,
Am 09.02.2017 um 01:13 schrieb Florian Fainelli:
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
- update the error path to clean up the module reference in case the
Generic PHY probe function fails
Fixes: cafe8df8b9bc ("net: phy: Fix lack of reference count on PHY driver")
Signed-off-by: Florian Fainelli <f.faine...@gmail.com>
---
drivers/net/phy/phy_device.c | 16 +++++++++++++++-
1 file changed, 15 insertions(+), 1 deletion(-)
just stumbled over this bug on an am335x based board, with an
KSZ8081 attached, so there a "fixed-link" is used like:
http://git.kernel.org/cgit/linux/kernel/git/torvalds/linux.git/tree/arch/arm/boot/dts/am335x-baltos-ir3220.dts#n105
With your patch it crashes also ...
If I remove this part:
diff --git a/drivers/net/phy/phy_device.c b/drivers/net/phy/phy_device.c
index d63d190..9dd08a4 100644
--- a/drivers/net/phy/phy_device.c
+++ b/drivers/net/phy/phy_device.c
@@ -921,11 +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
it boots again .. I think, you forgot? simply this remove ?
bye,
Heiko
diff --git a/drivers/net/phy/phy_device.c b/drivers/net/phy/phy_device.c
index 0d8f4d3847f6..d63d190a95ef 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
@@ -938,12 +939,22 @@ 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) {
@@ -981,6 +992,9 @@ int phy_attach_direct(struct net_device *dev, struct
phy_device *phydev,
error:
phy_detach(phydev);
+error_module_put:
+ module_put(d->driver->owner);
+error_put_device:
put_device(d);
module_put(d->driver->owner);
if (ndev_owner != bus->owner)
--
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