A slow bowler delivers a ball that passes the striker above the height of his waist, without pitching, and goes through to the wicket-keeper. The striker was standing upright in his ground when the ball passed him. What does the umpire do?

In cricket, for a SLOW bowler, a full toss above waist height is NOT a no ball. Law 41.6.1 only penalizes fast short-pitched deliveries and fast high full tosses above waist/shoulder height. Since this is a slow bowler, the delivery is legal regardless of height, and the striker played at it by letting it pass, so no penalty applies.