soraka silence vs smite

No. Teleport and flash can be blocked by CC, but otherwise, all summoner spells can be used at any time. This means I can smite even when I am stunned. The only thing that blocks summoner spell usage is suppression, such as Warwick, Malzahar or Skarner ult.

You can use Smite while stunned and knocked up, but silence and suppress will prevent you from using summoner spells.