openvswitch: supply a dummy err_handler of gre_cisco_protocol to prevent kernel crash
authorWei Zhang <asuka.com@163.com>
Sat, 28 Jun 2014 19:34:53 +0000 (12:34 -0700)
committerPravin B Shelar <pshelar@nicira.com>
Sun, 29 Jun 2014 21:10:48 +0000 (14:10 -0700)
When use gre vport, openvswitch register a gre_cisco_protocol but
does not supply a err_handler with it. The gre_cisco_err() in
net/ipv4/gre_demux.c expect err_handler be provided with the
gre_cisco_protocol implementation, and call ->err_handler() without
existence check, cause the kernel crash.

This patch provide a err_handler to fix this bug.
This bug introduced by commit aa310701e787087d (openvswitch: Add gre
tunnel support.)

Signed-off-by: Wei Zhang <asuka.com@163.com>
Signed-off-by: Jesse Gross <jesse@nicira.com>
Signed-off-by: Pravin B Shelar <pshelar@nicira.com>
net/openvswitch/vport-gre.c

index 35ec4fed09e228c7e6fe889d2701cb3a3de7748a..f49148a07da29037c0799ab122b18b1d4d0599cd 100644 (file)
@@ -110,6 +110,22 @@ static int gre_rcv(struct sk_buff *skb,
        return PACKET_RCVD;
 }
 
+/* Called with rcu_read_lock and BH disabled. */
+static int gre_err(struct sk_buff *skb, u32 info,
+                  const struct tnl_ptk_info *tpi)
+{
+       struct ovs_net *ovs_net;
+       struct vport *vport;
+
+       ovs_net = net_generic(dev_net(skb->dev), ovs_net_id);
+       vport = rcu_dereference(ovs_net->vport_net.gre_vport);
+
+       if (unlikely(!vport))
+               return PACKET_REJECT;
+       else
+               return PACKET_RCVD;
+}
+
 static int gre_tnl_send(struct vport *vport, struct sk_buff *skb)
 {
        struct net *net = ovs_dp_get_net(vport->dp);
@@ -186,6 +202,7 @@ error:
 
 static struct gre_cisco_protocol gre_protocol = {
        .handler        = gre_rcv,
+       .err_handler    = gre_err,
        .priority       = 1,
 };