[PATCH net] bonding: fix bond dev flags after convert to arphrd_ether

[Nikolay Aleksandrov <razor@blackwall.org>]

From: Nikolay Aleksandrov <nikolay@cumulusnetworks.com>

If a bonding device enslaves devices != arphrd_ether it'll change types
and if later these devices are released, it can enslave an arphrd_ether
device and switch back calling ether_setup() which resets dev->flags to
IFF_BROADCAST|IFF_MULTICAST and clears IFF_MASTER which then could lead
to many different bugs. This bug seems to have been there since the
introduction of ether_setup() in bond_enslave().

Signed-off-by: Nikolay Aleksandrov <nikolay@cumulusnetworks.com>
Fixes: e36b9d16c6a6 ("bonding: clean muticast addresses when device changes type")
---
 drivers/net/bonding/bond_main.c | 1 +
 1 file changed, 1 insertion(+)

diff --git a/drivers/net/bonding/bond_main.c b/drivers/net/bonding/bond_main.c
index 317a49480475..8ba119896e55 100644
--- a/drivers/net/bonding/bond_main.c
+++ b/drivers/net/bonding/bond_main.c
@@ -1368,6 +1368,7 @@ int bond_enslave(struct net_device *bond_dev, struct net_device *slave_dev)
 				bond_setup_by_slave(bond_dev, slave_dev);
 			else {
 				ether_setup(bond_dev);
+				bond_dev->flags |= IFF_MASTER;
 				bond_dev->priv_flags &= ~IFF_TX_SKB_SHARING;
 			}
 
-- 
1.9.3