[PATCH] the macvlan device causes SLAB corruption on network namespace exit.

[Anders Franzen <anders.franzen@ericsson.com>]

When doing exit from a network namespace, cleanup functions are executed from
the function default_device_exit_batch.
In the macvlan device, this will generate a call to macvlan_dellink.
If it is the last macvlan using a ''lowerdev'' the port is
destroyed.

Later the a call to macvlan_stop is executed. when the macvlan_hash_del(vlan) is
executed, the memory of the already freed port will be corrupted.

Signed-off-by: Anders Franzen <anders.franzen@ericsson.com>
---
 drivers/net/macvlan.c |    4 +++-
 1 files changed, 3 insertions(+), 1 deletions(-)

diff --git a/drivers/net/macvlan.c b/drivers/net/macvlan.c
index 6ed577b..c1cddb6 100644
--- a/drivers/net/macvlan.c
+++ b/drivers/net/macvlan.c
@@ -338,7 +338,9 @@ static int macvlan_stop(struct net_device *dev)
 	dev_uc_del(lowerdev, dev->dev_addr);
 
 hash_del:
-	macvlan_hash_del(vlan);
+	if (macvlan_port_exists(lowerdev))
+		macvlan_hash_del(vlan);
+
 	return 0;
 }
 
-- 
1.7.2.3