bonding: disallow enslaving a bond to itself

Enslaving a bond to itself leads to an endless loop and hangs the kernel.

Signed-off-by: Jiri Bohac <jbohac@suse.cz>
Tested-by: Ding Tianhong <dingtianhong@huawei.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

diff --git a/drivers/net/bonding/bond_main.c b/drivers/net/bonding/bond_main.c
index b47fa0421e01e63231fd659c02ed04ffbd89ca52..e5628fc725c3fc3885b7deac79074caa41edbae4 100644 (file)
--- a/drivers/net/bonding/bond_main.c
+++ b/drivers/net/bonding/bond_main.c
@@ -1197,6 +1197,11 @@ int bond_enslave(struct net_device *bond_dev, struct net_device *slave_dev)
                return -EBUSY;
        }
 
+       if (bond_dev == slave_dev) {
+               pr_err("%s: cannot enslave bond to itself.\n", bond_dev->name);
+               return -EPERM;
+       }
+
        /* vlan challenged mutual exclusion */
        /* no need to lock since we're protected by rtnl_lock */
        if (slave_dev->features & NETIF_F_VLAN_CHALLENGED) {