check if the socket exists before closing

modules/auxiliary/scanner/portscan/tcp.rb

@@ -80,8 +80,10 @@ class MetasploitModule < Msf::Auxiliary
                 'ConnectTimeout' => (timeout / 1000.0)
               }
             )
+            if s
               print_status("#{ip}:#{port} - TCP OPEN")
               r << [ip,port,"open"]
+            end
           rescue ::Rex::ConnectionRefused
             vprint_status("#{ip}:#{port} - TCP closed")
             r << [ip,port,"closed"]
@@ -92,10 +94,12 @@ class MetasploitModule < Msf::Auxiliary
           rescue ::Exception => e
             print_error("#{ip}:#{port} exception #{e.class} #{e} #{e.backtrace}")
           ensure
+            if s
               disconnect(s) rescue nil
             end
           end
         end
+      end
       t.each {|x| x.join }
 
       rescue ::Timeout::Error