Patch "net/bonding: Enforce active-backup policy for IPoIB bonds" has been added to the 4.7-stable tree

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

net/bonding: Enforce active-backup policy for IPoIB bonds

to the 4.7-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:
net-bonding-enforce-active-backup-policy-for-ipoib-bonds.patch
and it can be found in the queue-4.7 subdirectory.

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

From: Mark Bloch <[email protected]>
Date: Thu, 21 Jul 2016 11:52:55 +0300
Subject: net/bonding: Enforce active-backup policy for IPoIB bonds

From: Mark Bloch <[email protected]>

[ Upstream commit 1533e77315220dc1d5ec3bd6d9fe32e2aa0a74c0 ]

When using an IPoIB bond currently only active-backup mode is a valid use case and this commit strengthens it.

Since commit 2ab82852a270 ("net/bonding: Enable bonding to enslave netdevices not supporting set_mac_address()") was introduced till 4.7-rc1, IPoIB didn't support the set_mac_address ndo, and hence the fail over mac policy always applied to IPoIB bonds.

With the introduction of commit 492a7e67ff83 ("IB/IPoIB: Allow setting the device address"), that doesn't hold and practically IPoIB bonds are broken as of that. To fix it, lets go to fail over mac if the device doesn't support the ndo OR this is IPoIB device.

As a by-product, this commit also prevents a stack corruption which occurred when trying to copy 20 bytes (IPoIB) device address to a sockaddr struct that has only 16 bytes of storage.

---
 drivers/net/bonding/bond_main.c |   11 ++++++++++-
 1 file changed, 10 insertions(+), 1 deletion(-)

@@ -1422,7 +1422,16 @@ int bond_enslave(struct net_device *bond
 		return -EINVAL;
 	}
 
-	if (slave_ops->ndo_set_mac_address == NULL) {
+	if (slave_dev->type == ARPHRD_INFINIBAND &&
+	    BOND_MODE(bond) != BOND_MODE_ACTIVEBACKUP) {
+		netdev_warn(bond_dev, "Type (%d) supports only active-backup mode\n",
+			    slave_dev->type);
+		res = -EOPNOTSUPP;
+		goto err_undo_flags;
+	}
+
+	if (!slave_ops->ndo_set_mac_address ||
+	    slave_dev->type == ARPHRD_INFINIBAND) {
 		netdev_warn(bond_dev, "The slave device specified does not support setting the MAC address\n");
 		if (BOND_MODE(bond) == BOND_MODE_ACTIVEBACKUP &&
 		    bond->params.fail_over_mac != BOND_FOM_ACTIVE) {

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

queue-4.7/net-bonding-enforce-active-backup-policy-for-ipoib-bonds.patch