output: #fixed code
                                  @Override
      public boolean start() throws Exception {
  
          Cloud cloud = Jenkins.get().getCloud(cloudName);
          if (cloud == null) {
              throw new AbortException(String.format("Cloud does not exist: %s", cloudName));
          }
          if (!(cloud instanceof KubernetesCloud)) {
              throw new AbortException(String.format("Cloud is not a Kubernetes cloud: %s (%s)", cloudName,
                      cloud.getClass().getName()));
          }
          KubernetesCloud kubernetesCloud = (KubernetesCloud) cloud;
  
          Run<?, ?> run = getContext().get(Run.class);
          if (kubernetesCloud.isUsageRestricted()) {
              checkAccess(run, kubernetesCloud);
          }
  
          PodTemplateContext podTemplateContext = getContext().get(PodTemplateContext.class);
          String parentTemplates = podTemplateContext != null ? podTemplateContext.getName() : null;
  
          String label = step.getLabel();
          if (label == null) {
              label = labelify(run.getExternalizableId());
          }
  
          //Let's generate a random name based on the user specified to make sure that we don't have
          //issues with concurrent builds, or messing with pre-existing configuration
          String randString = RandomStringUtils.random(5, "bcdfghjklmnpqrstvwxz0123456789");
          String stepName = step.getName();
          if (stepName == null) {
              stepName = label;
          }
          String name = String.format(NAME_FORMAT, stepName, randString);
          String namespace = checkNamespace(kubernetesCloud, podTemplateContext);
  
          newTemplate = new PodTemplate();
          newTemplate.setName(name);
          newTemplate.setNamespace(namespace);
  
          if (step.getInheritFrom() == null) {
              newTemplate.setInheritFrom(Strings.emptyToNull(parentTemplates));
          } else {
              newTemplate.setInheritFrom(Strings.emptyToNull(step.getInheritFrom()));
          }
          newTemplate.setInstanceCap(step.getInstanceCap());
          newTemplate.setIdleMinutes(step.getIdleMinutes());
          newTemplate.setSlaveConnectTimeout(step.getSlaveConnectTimeout());
          newTemplate.setLabel(label);
          newTemplate.setEnvVars(step.getEnvVars());
          newTemplate.setVolumes(step.getVolumes());
          if (step.getWorkspaceVolume() != null) {
              newTemplate.setWorkspaceVolume(step.getWorkspaceVolume());
          }
          newTemplate.setContainers(step.getContainers());
          newTemplate.setNodeSelector(step.getNodeSelector());
          newTemplate.setNodeUsageMode(step.getNodeUsageMode());
          newTemplate.setServiceAccount(step.getServiceAccount());
          newTemplate.setAnnotations(step.getAnnotations());
          newTemplate.setYamlMergeStrategy(step.getYamlMergeStrategy());
          if(run!=null) {
              String url = ((KubernetesCloud)cloud).getJenkinsUrlOrNull();
              if(url != null) {
                  newTemplate.getAnnotations().add(new PodAnnotation("buildUrl", url + run.getUrl()));
              }
          }
          newTemplate.setImagePullSecrets(
                  step.getImagePullSecrets().stream().map(x -> new PodImagePullSecret(x)).collect(toList()));
          newTemplate.setYaml(step.getYaml());
          if (step.isShowRawYamlSet()) {
              newTemplate.setShowRawYaml(step.isShowRawYaml());
          }
          newTemplate.setPodRetention(step.getPodRetention());
  
          if(step.getActiveDeadlineSeconds() != 0) {
              newTemplate.setActiveDeadlineSeconds(step.getActiveDeadlineSeconds());
          }
  
          for (ContainerTemplate container : newTemplate.getContainers()) {
              if (!PodTemplateUtils.validateContainerName(container.getName())) {
                  throw new AbortException(Messages.RFC1123_error(container.getName()));
              }
          }
          Collection<String> errors = PodTemplateUtils.validateYamlContainerNames(newTemplate.getYamls());
          if (!errors.isEmpty()) {
              throw new AbortException(Messages.RFC1123_error(String.join(", ", errors)));
          }
  
          // Note that after JENKINS-51248 this must be a single label atom, not a space-separated list, unlike PodTemplate.label generally.
          if (!PodTemplateUtils.validateLabel(newTemplate.getLabel())) {
              throw new AbortException(Messages.label_error(newTemplate.getLabel()));
          }
  
          kubernetesCloud.addDynamicTemplate(newTemplate);
          BodyInvoker invoker = getContext().newBodyInvoker().withContexts(step, new PodTemplateContext(namespace, name)).withCallback(new PodTemplateCallback(newTemplate));
          if (step.getLabel() == null) {
              invoker.withContext(EnvironmentExpander.merge(getContext().get(EnvironmentExpander.class), EnvironmentExpander.constant(Collections.singletonMap("POD_LABEL", label))));
          }
          invoker.start();
  
          return false;
      }
input: #vulnerable code 
                                  @Override
      public boolean start() throws Exception {
  
          Cloud cloud = Jenkins.getInstance().getCloud(cloudName);
          if (cloud == null) {
              throw new AbortException(String.format("Cloud does not exist: %s", cloudName));
          }
          if (!(cloud instanceof KubernetesCloud)) {
              throw new AbortException(String.format("Cloud is not a Kubernetes cloud: %s (%s)", cloudName,
                      cloud.getClass().getName()));
          }
          KubernetesCloud kubernetesCloud = (KubernetesCloud) cloud;
  
          Run<?, ?> run = getContext().get(Run.class);
          if (kubernetesCloud.isUsageRestricted()) {
              checkAccess(run, kubernetesCloud);
          }
  
          PodTemplateContext podTemplateContext = getContext().get(PodTemplateContext.class);
          String parentTemplates = podTemplateContext != null ? podTemplateContext.getName() : null;
  
          String label = step.getLabel();
          if (label == null) {
              label = labelify(run.getExternalizableId());
          }
  
          //Let's generate a random name based on the user specified to make sure that we don't have
          //issues with concurrent builds, or messing with pre-existing configuration
          String randString = RandomStringUtils.random(5, "bcdfghjklmnpqrstvwxz0123456789");
          String stepName = step.getName();
          if (stepName == null) {
              stepName = label;
          }
          String name = String.format(NAME_FORMAT, stepName, randString);
          String namespace = checkNamespace(kubernetesCloud, podTemplateContext);
  
          newTemplate = new PodTemplate();
          newTemplate.setName(name);
          newTemplate.setNamespace(namespace);
  
          if (step.getInheritFrom() == null) {
              newTemplate.setInheritFrom(Strings.emptyToNull(parentTemplates));
          } else {
              newTemplate.setInheritFrom(Strings.emptyToNull(step.getInheritFrom()));
          }
          newTemplate.setInstanceCap(step.getInstanceCap());
          newTemplate.setIdleMinutes(step.getIdleMinutes());
          newTemplate.setSlaveConnectTimeout(step.getSlaveConnectTimeout());
          newTemplate.setLabel(label);
          newTemplate.setEnvVars(step.getEnvVars());
          newTemplate.setVolumes(step.getVolumes());
          if (step.getWorkspaceVolume() != null) {
              newTemplate.setWorkspaceVolume(step.getWorkspaceVolume());
          }
          newTemplate.setContainers(step.getContainers());
          newTemplate.setNodeSelector(step.getNodeSelector());
          newTemplate.setNodeUsageMode(step.getNodeUsageMode());
          newTemplate.setServiceAccount(step.getServiceAccount());
          newTemplate.setAnnotations(step.getAnnotations());
          newTemplate.setYamlMergeStrategy(step.getYamlMergeStrategy());
          if(run!=null) {
              String url = ((KubernetesCloud)cloud).getJenkinsUrlOrNull();
              if(url != null) {
                  newTemplate.getAnnotations().add(new PodAnnotation("buildUrl", url + run.getUrl()));
              }
          }
          newTemplate.setImagePullSecrets(
                  step.getImagePullSecrets().stream().map(x -> new PodImagePullSecret(x)).collect(toList()));
          newTemplate.setYaml(step.getYaml());
          if (step.isShowRawYamlSet()) {
              newTemplate.setShowRawYaml(step.isShowRawYaml());
          }
          newTemplate.setPodRetention(step.getPodRetention());
  
          if(step.getActiveDeadlineSeconds() != 0) {
              newTemplate.setActiveDeadlineSeconds(step.getActiveDeadlineSeconds());
          }
  
          for (ContainerTemplate container : newTemplate.getContainers()) {
              if (!PodTemplateUtils.validateContainerName(container.getName())) {
                  throw new AbortException(Messages.RFC1123_error(container.getName()));
              }
          }
          Collection<String> errors = PodTemplateUtils.validateYamlContainerNames(newTemplate.getYamls());
          if (!errors.isEmpty()) {
              throw new AbortException(Messages.RFC1123_error(String.join(", ", errors)));
          }
  
          // Note that after JENKINS-51248 this must be a single label atom, not a space-separated list, unlike PodTemplate.label generally.
          if (!PodTemplateUtils.validateLabel(newTemplate.getLabel())) {
              throw new AbortException(Messages.label_error(newTemplate.getLabel()));
          }
  
          kubernetesCloud.addDynamicTemplate(newTemplate);
          BodyInvoker invoker = getContext().newBodyInvoker().withContexts(step, new PodTemplateContext(namespace, name)).withCallback(new PodTemplateCallback(newTemplate));
          if (step.getLabel() == null) {
              invoker.withContext(EnvironmentExpander.merge(getContext().get(EnvironmentExpander.class), EnvironmentExpander.constant(Collections.singletonMap("POD_LABEL", label))));
          }
          invoker.start();
  
          return false;
      } 
                              #location 4 
                              #vulnerability type NULL_DEREFERENCE