Add comment for using copy slice

controlplane/kubeadm/api/v1beta1/kubeadm_control_plane_webhook.go

@@ -431,6 +431,8 @@ func paths(path []string, diff map[string]interface{}) [][]string {
 	for key, m := range diff {
 		nested, ok := m.(map[string]interface{})
 		if !ok {
+			// We have to use a copy of path, because otherwise the slice we append to
+			// allPaths would be overwritten in another iteration.
 			tmp := make([]string, len(path))
 			copy(tmp, path)
 			allPaths = append(allPaths, append(tmp, key))