From 0da7130a1ace84869742521bac5831d1f5d183e5 Mon Sep 17 00:00:00 2001
From: Mahmood Ali <mahmood@hashicorp.com>
Date: Tue, 17 Mar 2020 21:35:56 -0400
Subject: [PATCH] Protect against args being modified

---
 nomad/node_endpoint.go | 9 ++++++---
 1 file changed, 6 insertions(+), 3 deletions(-)

diff --git a/nomad/node_endpoint.go b/nomad/node_endpoint.go
index f635abc27..e26891349 100644
--- a/nomad/node_endpoint.go
+++ b/nomad/node_endpoint.go
@@ -78,11 +78,12 @@ type Node struct {
 
 // Register is used to upsert a client that is available for scheduling
 func (n *Node) Register(args *structs.NodeRegisterRequest, reply *structs.NodeUpdateResponse) error {
+	isForwarded := args.IsForwarded()
 	if done, err := n.srv.forward("Node.Register", args, args, reply); done {
 		// We have a valid node connection since there is no error from the
 		// forwarded server, so add the mapping to cache the
 		// connection and allow the server to send RPCs to the client.
-		if err == nil && n.ctx != nil && n.ctx.NodeID == "" && !args.IsForwarded() {
+		if err == nil && n.ctx != nil && n.ctx.NodeID == "" && !isForwarded {
 			n.ctx.NodeID = args.Node.ID
 			n.srv.addNodeConn(n.ctx)
 		}
@@ -370,11 +371,12 @@ func (n *Node) deregister(args *structs.NodeBatchDeregisterRequest,
 
 // UpdateStatus is used to update the status of a client node
 func (n *Node) UpdateStatus(args *structs.NodeUpdateStatusRequest, reply *structs.NodeUpdateResponse) error {
+	isForwarded := args.IsForwarded()
 	if done, err := n.srv.forward("Node.UpdateStatus", args, args, reply); done {
 		// We have a valid node connection since there is no error from the
 		// forwarded server, so add the mapping to cache the
 		// connection and allow the server to send RPCs to the client.
-		if err == nil && n.ctx != nil && n.ctx.NodeID == "" && !args.IsForwarded() {
+		if err == nil && n.ctx != nil && n.ctx.NodeID == "" && !isForwarded {
 			n.ctx.NodeID = args.NodeID
 			n.srv.addNodeConn(n.ctx)
 		}
@@ -921,11 +923,12 @@ func (n *Node) GetAllocs(args *structs.NodeSpecificRequest,
 // per allocation.
 func (n *Node) GetClientAllocs(args *structs.NodeSpecificRequest,
 	reply *structs.NodeClientAllocsResponse) error {
+	isForwarded := args.IsForwarded()
 	if done, err := n.srv.forward("Node.GetClientAllocs", args, args, reply); done {
 		// We have a valid node connection since there is no error from the
 		// forwarded server, so add the mapping to cache the
 		// connection and allow the server to send RPCs to the client.
-		if err == nil && n.ctx != nil && n.ctx.NodeID == "" && !args.IsForwarded() {
+		if err == nil && n.ctx != nil && n.ctx.NodeID == "" && !isForwarded {
 			n.ctx.NodeID = args.NodeID
 			n.srv.addNodeConn(n.ctx)
 		}