Patch "sh_eth: Fix ethtool operation crash when net device is down" has been added to the 3.18-stable tree

This is a note to let you know that I've just added the patch titled

sh_eth: Fix ethtool operation crash when net device is down

to the 3.18-stable tree which can be found at:
http://www.kernel.org/git/?p=linux/kernel/git/stable/stable-queue.git;a=summary

The filename of the patch is:
sh_eth-fix-ethtool-operation-crash-when-net-device-is-down.patch
and it can be found in the queue-3.18 subdirectory.

If you, or anyone else, feels it should not be added to the stable tree, please let <[email protected]> know about it.

From: Ben Hutchings <[email protected]>
Date: Fri, 16 Jan 2015 17:51:25 +0000
Subject: sh_eth: Fix ethtool operation crash when net device is down

From: Ben Hutchings <[email protected]>

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

---
 drivers/net/ethernet/renesas/sh_eth.c |   10 ++++++++++
 1 file changed, 10 insertions(+)

@@ -1832,6 +1832,9 @@ static int sh_eth_get_settings(struct ne
 	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 ne
 	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_
 	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_devic
 	if (mdp->phydev) {
 		phy_stop(mdp->phydev);
 		phy_disconnect(mdp->phydev);
+		mdp->phydev = NULL;
 	}
 
 	free_irq(ndev->irq, ndev);

Patches currently in stable-queue which might be from [email protected] are

queue-3.18/sh_eth-fix-ethtool-operation-crash-when-net-device-is-down.patch