PVS-Studio warning V505 for DeSmuME

ArchiveFile::ArchiveFile(const char* filename)
{
  ...
  for(size_t i = 0;
      i < s_formatInfos.size() && m_typeIndex < 0;
      i++)
  {
    ...
    char* fileSig = (char*)_alloca(len);
    ...
  }
  ...
}

This suspicious code was found in DeSmuME project by PVS-Studio static code analyzer.
Warning message is:
V505 The 'alloca' function is used inside the loop. This can quickly overflow stack. DeSmuME_VS2005 7zip.cpp 161

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/