Most if not all channelled abilities are disabled with a stun. However not Geist's Life Drain. This might be intended, but feels overpowered for an ability that can auto-aim and lock on, even when she is stunned.
Geist's Life Drain isn't actually a channeled ability, but a debuff she applies to you to drain you when youre in range and in LOS. Dispel Magic works to stop the drain early if she's draining you.
