PVS-Studio warning V611 for Firefox

NPError
NPP_New(....)
{
  ....
  InstanceData* instanceData = new InstanceData;
  ....
  NPError err = pluginInstanceInit(instanceData);
  if (err != NPERR_NO_ERROR) {
    NPN_ReleaseObject(scriptableObject);
    free(instanceData);
    return err;
  }
  ....
}

This suspicious code was found in Firefox project by PVS-Studio static code analyzer.
Warning message is:
V611 The memory was allocated using 'new' operator but was released using the 'free' function. Consider inspecting operation logics behind the 'instanceData' variable. nptest.cpp 1029

PVS-Studio is a static analyzer for detecting bugs in the source code of applications written in C, C++, C++11, C++/CX. Site: http://www.viva64.com/en/pvs-studio/