Commit 0553c891 authored Apr 14, 2011 by Krishna Kumar Committed by David S. Miller Apr 17, 2011

ip6_pol_route panic: Do not allow VLAN on loopback



Several tests in the ipv6 routing code check IFF_LOOPBACK, and
allowing stacking such as VLAN'ing on top of loopback results in a
netdevice which reports IFF_LOOPBACK but really isn't the loopback
device.

Instead of spamming the ipv6 routing code with even more special tests,
simply disallow VLAN over loopback.

The result of this patch is:

# modprobe 8021q
# vconfig add lo 43
ERROR: trying to add VLAN #43 to IF -:lo:-  error: Operation not supported

Signed-off-by: Krishna Kumar <krkumar2@in.ibm.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

parent 70dda99c

drivers/net/loopback.c

+2 −1

Original line number	Diff line number	Diff line
		@@ -173,7 +173,8 @@ static void loopback_setup(struct net_device *dev)
		\| NETIF_F_RXCSUM
		\| NETIF_F_HIGHDMA
		\| NETIF_F_LLTX
		\| NETIF_F_NETNS_LOCAL;
		\| NETIF_F_NETNS_LOCAL
		\| NETIF_F_VLAN_CHALLENGED;
		dev->ethtool_ops = &loopback_ethtool_ops;
		dev->header_ops = &eth_header_ops;
		dev->netdev_ops = &loopback_ops;

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