OVS actions like pop_eth followed by pop_mpls(ETH_P_TEB) or pop_nsh
can expose an inner Ethernet header which is not in the linear part
of the skb. Output to an internal port then crashes in eth_type_trans():
flow: in_port(0),eth(),eth_type(0x8847),mpls(lse=0x00010140)
actions: pop_eth,pop_mpls(0x6558),0
# AF_PACKET SOCK_RAW on dp0: eth / mpls / eth / 4096 bytes of payload
kernel BUG at include/linux/skbuff.h:2839!
RIP: 0010:eth_type_trans (include/linux/etherdevice.h:635
net/ethernet/eth.c:163)
Call Trace:
internal_dev_recv (net/openvswitch/vport-internal_dev.c:202) openvswitch
do_execute_actions (net/openvswitch/actions.c:1296) openvswitch
ovs_execute_actions (net/openvswitch/actions.c:1606) openvswitch
ovs_dp_process_packet (net/openvswitch/datapath.c:310) openvswitch
ovs_vport_receive (net/openvswitch/vport.c:448) openvswitch
internal_dev_xmit (net/openvswitch/vport-internal_dev.c:42) openvswitch
dev_hard_start_xmit (include/linux/netdevice.h:5455
include/linux/netdevice.h:5464 net/core/dev.c:4057 net/core/dev.c:4073)
__dev_queue_xmit (net/core/dev.c:5066)
packet_sendmsg (net/packet/af_packet.c:3157 net/packet/af_packet.c:3189)
Use eth_type_trans_careful(), and drop the packet if the Ethernet
header can not be pulled. This covers all OVS actions at the consumer,
instead of fixing each producer.
Fixes: b2d0f5d5dc53 ("openvswitch: enable NSH support")
Fixes: f66b53fdbb22 ("openvswitch: New MPLS actions for layer 2 tunnelling")
Signed-off-by: Eric Dumazet <[email protected]>
---
net/openvswitch/vport-internal_dev.c | 8 +++++++-
1 file changed, 7 insertions(+), 1 deletion(-)
diff --git a/net/openvswitch/vport-internal_dev.c
b/net/openvswitch/vport-internal_dev.c
index
77a16d5ebd54343c80a2def261aadcb8ff0d1274..8f035087f0eec80eddf6b493cf5ba7915a3e01c6
100644
--- a/net/openvswitch/vport-internal_dev.c
+++ b/net/openvswitch/vport-internal_dev.c
@@ -188,6 +188,7 @@ static void internal_dev_destroy(struct vport *vport)
static int internal_dev_recv(struct sk_buff *skb)
{
struct net_device *netdev = skb->dev;
+ enum skb_drop_reason reason;
if (unlikely(!(netdev->flags & IFF_UP))) {
kfree_skb(skb);
@@ -199,7 +200,12 @@ static int internal_dev_recv(struct sk_buff *skb)
nf_reset_ct(skb);
skb->pkt_type = PACKET_HOST;
- skb->protocol = eth_type_trans(skb, netdev);
+ reason = eth_type_trans_careful(skb, netdev);
+ if (unlikely(reason)) {
+ dev_core_stats_rx_dropped_inc(netdev);
+ kfree_skb_reason(skb, reason);
+ return NETDEV_TX_OK;
+ }
skb_postpull_rcsum(skb, eth_hdr(skb), ETH_HLEN);
dev_sw_netstats_rx_add(netdev, skb->len);
--
2.53.0
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