output: #fixed code
                                  public byte[] getChannelConfigurationBytes() throws TransactionException {
          try {
              final Block configBlock = getConfigBlock(getRandomPeer());
  
              Envelope envelopeRet = Envelope.parseFrom(configBlock.getData().getData(0));
  
              Payload payload = Payload.parseFrom(envelopeRet.getPayload());
  
              ConfigEnvelope configEnvelope = ConfigEnvelope.parseFrom(payload.getData());
              return configEnvelope.getConfig().toByteArray();
  
          } catch (Exception e) {
              throw new TransactionException(e);
          }
  
      }
input: #vulnerable code 
                                  public byte[] getChannelConfigurationBytes() throws TransactionException {
          try {
              final Block configBlock = getConfigurationBlock();
  
              Envelope envelopeRet = Envelope.parseFrom(configBlock.getData().getData(0));
  
              Payload payload = Payload.parseFrom(envelopeRet.getPayload());
  
              ConfigEnvelope configEnvelope = ConfigEnvelope.parseFrom(payload.getData());
              return configEnvelope.getConfig().toByteArray();
  
          } catch (Exception e) {
              throw new TransactionException(e);
          }
  
      } 
                              #location 3 
                              #vulnerability type THREAD_SAFETY_VIOLATION