Você precisa de um visto de trânsito canadense .
Do site canadense acima:
Who needs a transit visa?
You need a transit visa if you are from a visa-required country and:
your international flight stops at a Canadian airport on its way to another country
you will be connecting between two international flights at a Canadian airport
- Some people can transit through Canada without a visa if they are travelling to or from the United States.
Você pode verificar aqui .