[PATCH net 2/4] openvswitch: supply a dummy err_handler of gre_cisco_protocol to prevent kernel crash
From: Pravin B Shelar <hidden>
Date: 2014-07-01 06:34:36
Subsystem:
networking [general], openvswitch, the rest · Maintainers:
"David S. Miller", Eric Dumazet, Jakub Kicinski, Paolo Abeni, Aaron Conole, Eelco Chaudron, Ilya Maximets, Linus Torvalds
From: Wei Zhang <redacted> 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 <redacted> Signed-off-by: Jesse Gross <redacted> Signed-off-by: Pravin B Shelar <redacted> --- net/openvswitch/vport-gre.c | 17 +++++++++++++++++ 1 file changed, 17 insertions(+)
diff --git a/net/openvswitch/vport-gre.c b/net/openvswitch/vport-gre.c
index 35ec4fe..f49148a 100644
--- a/net/openvswitch/vport-gre.c
+++ b/net/openvswitch/vport-gre.c@@ -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, };
--
1.9.3