#vulnerable code 
                                @Override
    public OSService[] getServices() {
        // Get running services
        List<OSService> services = new ArrayList<>();
        Set<String> running = new HashSet<>();
        for (OSProcess p : getChildProcesses(1, 0, ProcessSort.PID)) {
            OSService s = new OSService(p.getName(), p.getProcessID(), RUNNING);
            services.add(s);
            running.add(p.getName());
        }
        // Get Directories for stopped services
        File dir = new File("/etc/rc.d");
        if (dir.exists() && dir.isDirectory()) {
            for (File f : dir.listFiles()) {
                String name = f.getName();
                if (!running.contains(name)) {
                    OSService s = new OSService(name, 0, STOPPED);
                    services.add(s);
                }
            }
        } else {
            LOG.error("Directory: /etc/init does not exist");
        }
        return services.toArray(new OSService[0]);
    } 
                            #location 14 
                            #vulnerability type NULL_DEREFERENCE
#fixed code
                                @Override
    public OSService[] getServices() {
        // Get running services
        List<OSService> services = new ArrayList<>();
        Set<String> running = new HashSet<>();
        for (OSProcess p : getChildProcesses(1, 0, ProcessSort.PID)) {
            OSService s = new OSService(p.getName(), p.getProcessID(), RUNNING);
            services.add(s);
            running.add(p.getName());
        }
        // Get Directories for stopped services
        File dir = new File("/etc/rc.d");
        File[] listFiles;
        if (dir.exists() && dir.isDirectory() && (listFiles = dir.listFiles()) != null) {
            for (File f : listFiles) {
                String name = f.getName();
                if (!running.contains(name)) {
                    OSService s = new OSService(name, 0, STOPPED);
                    services.add(s);
                }
            }
        } else {
            LOG.error("Directory: /etc/init does not exist");
        }
        return services.toArray(new OSService[0]);
    }