net: openvswitch: release vport resources on failure

A recent commit introducing upcall packet accounting failed to properly
release the vport object when the per-cpu stats struct couldn't be
allocated.  This can cause dangling pointers to dp objects long after
they've been released.

Cc: wangchuanlei <wangchuanlei@inspur.com>
Fixes: 1933ea3 ("net: openvswitch: Add support to count upcall packets")
Reported-by: syzbot+8f4e2dcfcb3209ac35f9@syzkaller.appspotmail.com
Signed-off-by: Aaron Conole <aconole@redhat.com>
Acked-by: Eelco Chaudron <echaudro@redhat.com>
Reviewed-by: Michal Swiatkowski <michal.swiatkowski@linux.intel.com>
Link: https://lore.kernel.org/r/20221220212717.526780-1-aconole@redhat.com
Signed-off-by: Jakub Kicinski <kuba@kernel.org>

net/openvswitch/datapath.c

@@ -1861,7 +1861,7 @@ static int ovs_dp_cmd_new(struct sk_buff *skb, struct genl_info *info)
 	vport->upcall_stats = netdev_alloc_pcpu_stats(struct vport_upcall_stats_percpu);
 	if (!vport->upcall_stats) {
 		err = -ENOMEM;
-		goto err_destroy_portids;
+		goto err_destroy_vport;
 	}
 
 	err = ovs_dp_cmd_fill_info(dp, reply, info->snd_portid,
@@ -1876,6 +1876,8 @@ static int ovs_dp_cmd_new(struct sk_buff *skb, struct genl_info *info)
 	ovs_notify(&dp_datapath_genl_family, reply, info);
 	return 0;
 
+err_destroy_vport:
+	ovs_dp_detach_port(vport);
 err_destroy_portids:
 	kfree(rcu_dereference_raw(dp->upcall_portids));
 err_unlock_and_destroy_meters:
@@ -2323,7 +2325,7 @@ static int ovs_vport_cmd_new(struct sk_buff *skb, struct genl_info *info)
 	vport->upcall_stats = netdev_alloc_pcpu_stats(struct vport_upcall_stats_percpu);
 	if (!vport->upcall_stats) {
 		err = -ENOMEM;
-		goto exit_unlock_free;
+		goto exit_unlock_free_vport;
 	}
 
 	err = ovs_vport_cmd_fill_info(vport, reply, genl_info_net(info),
@@ -2343,6 +2345,8 @@ static int ovs_vport_cmd_new(struct sk_buff *skb, struct genl_info *info)
 	ovs_notify(&dp_vport_genl_family, reply, info);
 	return 0;
 
+exit_unlock_free_vport:
+	ovs_dp_detach_port(vport);
 exit_unlock_free:
 	ovs_unlock();
 	kfree_skb(reply);