output: #fixed code
                                  @Override
      public DLegerEntry get(Long index) {
          PreConditions.check(index <= legerEndIndex && index >= legerBeginIndex, DLegerException.Code.INDEX_OUT_OF_RANGE, String.format("%d should between %d-%d", index, legerBeginIndex, legerEndIndex), memberState.getLeaderId());
          SelectMmapBufferResult indexSbr = indexFileQueue.getData(index * INDEX_NUIT_SIZE, INDEX_NUIT_SIZE);
          PreConditions.check(indexSbr.getByteBuffer() != null, DLegerException.Code.DISK_ERROR, null);
          indexSbr.getByteBuffer().getInt(); //magic
          long pos = indexSbr.getByteBuffer().getLong();
          int size = indexSbr.getByteBuffer().getInt();
          indexSbr.release();
          SelectMmapBufferResult dataSbr = dataFileQueue.getData(pos, size);
          PreConditions.check(dataSbr.getByteBuffer() != null, DLegerException.Code.DISK_ERROR, null);
          DLegerEntry dLegerEntry = DLegerEntryCoder.decode(dataSbr.getByteBuffer());
          dLegerEntry.setPos(pos);
          dataSbr.release();
          return dLegerEntry;
      }
input: #vulnerable code 
                                  @Override
      public DLegerEntry get(Long index) {
          PreConditions.check(index <= legerEndIndex && index >= legerBeginIndex, DLegerException.Code.INDEX_OUT_OF_RANGE, String.format("%d should between %d-%d", index, legerBeginIndex, legerEndIndex), memberState.getLeaderId());
          SelectMmapBufferResult indexSbr = indexFileQueue.getData(index * INDEX_NUIT_SIZE, INDEX_NUIT_SIZE);
          PreConditions.check(indexSbr.getByteBuffer() != null, DLegerException.Code.DISK_ERROR, null);
          indexSbr.getByteBuffer().getInt(); //magic
          long pos = indexSbr.getByteBuffer().getLong();
          int size = indexSbr.getByteBuffer().getInt();
          indexSbr.release();
          SelectMmapBufferResult dataSbr = dataFileQueue.getData(pos, size);
          PreConditions.check(dataSbr.getByteBuffer() != null, DLegerException.Code.DISK_ERROR, null);
          DLegerEntry dLegerEntry = DLegerEntryCoder.decode(dataSbr.getByteBuffer());
          dataSbr.release();
          return dLegerEntry;
      } 
                              #location 3 
                              #vulnerability type THREAD_SAFETY_VIOLATION