Subject: [PATCH] bonding: disallow enslaving a bond to itself

From: Jiri Bohac <[email-masked]>
Date: Wed, 26 Feb 2014 18:20:13 +0100

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

Signed-off-by: Jiri Bohac <[email-masked]>

diff --git a/drivers/net/bonding/bond_main.c b/drivers/net/bonding/bond_main.c
index 1c6104d..8f028ac 100644
--- a/drivers/net/bonding/bond_main.c
+++ b/drivers/net/bonding/bond_main.c
@@ -1193,6 +1193,11 @@ 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) {
-- 
Jiri Bohac <[email-masked]>
SUSE Labs, SUSE CZ