function allocNewPool(poolSize) {
  if (poolFragments.length > 0)
    pool = poolFragments.pop();
  else
    pool = Buffer.allocUnsafe(poolSize);
  pool.used = 0;
}
The software constructs all or part of an OS command using externally-influenced input from an upstream component, but it does not neutralize or incorrectly neutralizes special elements that could modify the intended OS command when it is sent to a downstream component.