[PATCH 4.15 122/128] ipvlan: add L2 check for packets arriving via virtual devices

Greg Kroah-Hartman
2018-03-16T15:46:02Z

From: Mahesh Bandewar <maheshb@google.com>

[ Upstream commit 92ff42645028fa6f9b8aa767718457b9264316b4 ]

Packets that don't have dest mac as the mac of the master device should
not be entertained by the IPvlan rx-handler. This is mostly true as the
packet path mostly takes care of that, except when the master device is
a virtual device. As demonstrated in the following case -

ip netns add ns1
ip link add ve1 type veth peer name ve2
ip link add link ve2 name iv1 type ipvlan mode l2
ip link set dev iv1 netns ns1
ip link set ve1 up
ip link set ve2 up
ip -n ns1 link set iv1 up
ip addr add 192.168.10.1/24 dev ve1
ip -n ns1 addr 192.168.10.2/24 dev iv1
ping -c2 192.168.10.2
<Works!>
ip neigh show dev ve1
ip neigh show 192.168.10.2 lladdr <random> dev ve1
ping -c2 192.168.10.2
<Still works! Wrong!!>

This patch adds that missing check in the IPvlan rx-handler.

Reported-by: Amit Sikka <amit.sikka@ericsson.com>
Signed-off-by: Mahesh Bandewar <maheshb@google.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Signed-off-by: Sasha Levin <alexander.levin@microsoft.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
---
drivers/net/ipvlan/ipvlan_core.c | 4 ++++
1 file changed, 4 insertions(+)

--- a/drivers/net/ipvlan/ipvlan_core.c
+++ b/drivers/net/ipvlan/ipvlan_core.c
@@ -322,6 +322,10 @@ static int ipvlan_rcv_frame(struct ipvl_
if (dev_forward_skb(ipvlan->dev, skb) == NET_RX_SUCCESS)
success = true;
} else {
+ if (!ether_addr_equal_64bits(eth_hdr(skb)->h_dest,
+ ipvlan->phy_dev->dev_addr))
+ skb->pkt_type = PACKET_OTHERHOST;
+
ret = RX_HANDLER_ANOTHER;
success = true;
}