The driver connects and disconnects the PHY device whenever the
net device is brought up and down. The ethtool get_settings,
set_settings and nway_reset operations will dereference a null
or dangling pointer if called while it is down.
I think it would be preferable to keep the PHY connected, but there
may be good reasons not to.
As an immediate fix for this bug:
- Set the phydev pointer to NULL after disconnecting the PHY
- Change those three operations to return -ENODEV while the PHY is
not connected
Signed-off-by: Ben Hutchings <ben.hutchings@codethink.co.uk>
Signed-off-by: David S. Miller <davem@davemloft.net>
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