PVS-Studio warning V505 for Synergy

size_t Rijndael::Enc::AdvancedProcessBlocks(....) const
{
  ....
  do {
    space = (byte *)alloca(255+sizeof(Locals));
    space += (256-(size_t)space%256)%256;
  }
  while (AliasedWithTable(space, space+sizeof(Locals)));
  ....
}

This suspicious code was found in Synergy project by PVS-Studio static code analyzer.
Warning message is:
V505 The 'alloca' function is used inside the loop. This can quickly overflow stack. rijndael.cpp 1206

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/