From: Ben Hutchings <ben.hutchings@xxxxxxxxxxxxxxx>
commit 4f9dce230b32eec45cec8c28cae61efdfa2f7d57 upstream.
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@xxxxxxxxxxxxxxx>
Signed-off-by: David S. Miller <davem@xxxxxxxxxxxxx>
Signed-off-by: Amit Pundir <amit.pundir@xxxxxxxxxx>
---
drivers/net/ethernet/renesas/sh_eth.c | 10 ++++++++++
1 file changed, 10 insertions(+)
diff --git a/drivers/net/ethernet/renesas/sh_eth.c b/drivers/net/ethernet/renesas/sh_eth.c
index c44bae495804..f25b5b8b120f 100644
--- a/drivers/net/ethernet/renesas/sh_eth.c
+++ b/drivers/net/ethernet/renesas/sh_eth.c
@@ -1832,6 +1832,9 @@ static int sh_eth_get_settings(struct net_device *ndev,
unsigned long flags;
int ret;
+ if (!mdp->phydev)
+ return -ENODEV;
+
spin_lock_irqsave(&mdp->lock, flags);
ret = phy_ethtool_gset(mdp->phydev, ecmd);
spin_unlock_irqrestore(&mdp->lock, flags);
@@ -1846,6 +1849,9 @@ static int sh_eth_set_settings(struct net_device *ndev,
unsigned long flags;
int ret;
+ if (!mdp->phydev)
+ return -ENODEV;
+
spin_lock_irqsave(&mdp->lock, flags);
/* disable tx and rx */
@@ -1880,6 +1886,9 @@ static int sh_eth_nway_reset(struct net_device *ndev)
unsigned long flags;
int ret;
+ if (!mdp->phydev)
+ return -ENODEV;
+
spin_lock_irqsave(&mdp->lock, flags);
ret = phy_start_aneg(mdp->phydev);
spin_unlock_irqrestore(&mdp->lock, flags);
@@ -2189,6 +2198,7 @@ static int sh_eth_close(struct net_device *ndev)
if (mdp->phydev) {
phy_stop(mdp->phydev);
phy_disconnect(mdp->phydev);
+ mdp->phydev = NULL;
}
free_irq(ndev->irq, ndev);
--
2.7.4