[3.16.y-ckt stable] Patch "bonding: Prevent IPv6 link local address on enslaved devices" has been added to the 3.16.y-ckt tree

[Luis Henriques]

This is a note to let you know that I have just added a patch titled

    bonding: Prevent IPv6 link local address on enslaved devices

to the linux-3.16.y-queue branch of the 3.16.y-ckt extended stable tree 
which can be found at:

    http://kernel.ubuntu.com/git/ubuntu/linux.git/log/?h=linux-3.16.y-queue

This patch is scheduled to be released in version 3.16.7-ckt24.

If you, or anyone else, feels it should not be added to this tree, please 
reply to this email.

For more information about the 3.16.y-ckt tree, see
https://wiki.ubuntu.com/Kernel/Dev/ExtendedStable

Thanks.
-Luis

---8<------------------------------------------------------------

>From e89bf2a454dde25fe85e44c7e5c7deea1125a3a4 Mon Sep 17 00:00:00 2001
From: Karl Heiss <kheiss at gmail.com>
Date: Mon, 11 Jan 2016 08:28:43 -0500
Subject: bonding: Prevent IPv6 link local address on enslaved devices

commit 03d84a5f83a67e692af00a3d3901e7820e3e84d5 upstream.

Commit 1f718f0f4f97 ("bonding: populate neighbour's private on enslave")
undoes the fix provided by commit c2edacf80e15 ("bonding / ipv6: no addrconf
for slaves separately from master") by effectively setting the slave flag
after the slave has been opened.  If the slave comes up quickly enough, it
will go through the IPv6 addrconf before the slave flag has been set and
will get a link local IPv6 address.

In order to ensure that addrconf knows to ignore the slave devices on state
change, set IFF_SLAVE before dev_open() during bonding enslavement.

Fixes: 1f718f0f4f97 ("bonding: populate neighbour's private on enslave")
Signed-off-by: Karl Heiss <kheiss at gmail.com>
Signed-off-by: Jay Vosburgh <jay.vosburgh at canonical.com>
Reviewed-by: Jarod Wilson <jarod at redhat.com>
Signed-off-by: Andy Gospodarek <gospo at cumulusnetworks.com>
Signed-off-by: David S. Miller <davem at davemloft.net>
Signed-off-by: Luis Henriques <luis.henriques at canonical.com>
---
 drivers/net/bonding/bond_main.c | 5 ++++-
 1 file changed, 4 insertions(+), 1 deletion(-)

diff --git a/drivers/net/bonding/bond_main.c b/drivers/net/bonding/bond_main.c
index 8fe94f711f39..8b555aca45eb 100644
--- a/drivers/net/bonding/bond_main.c
+++ b/drivers/net/bonding/bond_main.c
@@ -1179,7 +1179,6 @@ static int bond_master_upper_dev_link(struct net_device *bond_dev,
 	err = netdev_master_upper_dev_link_private(slave_dev, bond_dev, slave);
 	if (err)
 		return err;
-	slave_dev->flags |= IFF_SLAVE;
 	rtmsg_ifinfo(RTM_NEWLINK, slave_dev, IFF_SLAVE, GFP_KERNEL);
 	return 0;
 }
@@ -1392,6 +1391,9 @@ int bond_enslave(struct net_device *bond_dev, struct net_device *slave_dev)
 		}
 	}

+	/* set slave flag before open to prevent IPv6 addrconf */
+	slave_dev->flags |= IFF_SLAVE;
+
 	/* open the slave since the application closed it */
 	res = dev_open(slave_dev);
 	if (res) {
@@ -1643,6 +1645,7 @@ err_close:
 	dev_close(slave_dev);

 err_restore_mac:
+	slave_dev->flags &= ~IFF_SLAVE;
 	if (!bond->params.fail_over_mac ||
 	    BOND_MODE(bond) != BOND_MODE_ACTIVEBACKUP) {
 		/* XXX TODO - fom follow mode needs to change master's