Re: [PATCH net-next 1/9] openvswitch: Scrub packet in ovs_vport_receive()

On 31 July 2015 at 07:34, Hannes Frederic Sowa [off-list ref] wrote:

On Thu, 2015-07-30 at 11:12 -0700, Joe Stringer wrote:

quoted

Signed-off-by: Joe Stringer <redacted>
---
 net/openvswitch/vport.c | 3 +++
 1 file changed, 3 insertions(+)

diff --git a/net/openvswitch/vport.c b/net/openvswitch/vport.c
index d14f594..baa018f 100644
--- a/net/openvswitch/vport.c
+++ b/net/openvswitch/vport.c

@@ -475,6 +475,9 @@ void ovs_vport_receive(struct vport *vport, struct

sk_buff *skb,
      struct sw_flow_key key;
      int error;

+     if (!skb->sk || (sock_net(skb->sk) != read_pnet(&vport->dp
->net)))
+             skb_scrub_packet(skb, true);
+
      stats = this_cpu_ptr(vport->percpu_stats);
      u64_stats_update_begin(&stats->syncp);
      stats->rx_packets++;

In general, this shouldn't be necessary as the packet should already be
scrubbed before they arrive here.

Could you maybe add a WARN_ON and check how those skbs with conntrack
data traverse the stack? I also didn't understand why make it dependent
on the socket.

OK, sure. One case I could think of is with an OVS internal port in
another namespace, directly attached to the bridge. I'll have a play
around with WARN_ON and see if I can come up with something more
trimmed down.