openvswitch: Fix race.
ovs_vport_cmd_dump() did rcu_read_lock() only after getting the
datapath, which could have been deleted in between. Resolved by
taking rcu_read_lock() before the get_dp() call.
Signed-off-by: Jarno Rajahalme <jrajahalme@nicira.com>
Signed-off-by: Pravin B Shelar <pshelar@nicira.com>
diff --git a/net/openvswitch/datapath.c b/net/openvswitch/datapath.c
index e42340d..8601b32 100644
--- a/net/openvswitch/datapath.c
+++ b/net/openvswitch/datapath.c
@@ -1762,11 +1762,12 @@
int bucket = cb->args[0], skip = cb->args[1];
int i, j = 0;
- dp = get_dp(sock_net(skb->sk), ovs_header->dp_ifindex);
- if (!dp)
- return -ENODEV;
-
rcu_read_lock();
+ dp = get_dp(sock_net(skb->sk), ovs_header->dp_ifindex);
+ if (!dp) {
+ rcu_read_unlock();
+ return -ENODEV;
+ }
for (i = bucket; i < DP_VPORT_HASH_BUCKETS; i++) {
struct vport *vport;
