Venting a garage through the (attic) volume above the garage is a fire propagation risk in my opinion. If you feel the need to ventilate the garage, I suggest you install an appropriately-sized vent fan that exhausts through the garage wall.

Or leave the overhead garage door open for a bit.

The fire risk of passive-venting to attic makes sense, however I found nothing that says, "do not do this." The EPA also recommends external active venting ( Mechanical Ventilation for Attached Garage | Building America Solution Center (pnnl.gov) ).

So external active exhaust venting to exterior is the sanctioned option.

@3onthetree, leave overhead garage door open is not an option but thx anyway.

Does the space above the garage have decking? Used for storage? Could it be, if not?

"The fire risk of passive-venting to attic makes sense, however I found nothing that says, "do not do this." If your local building code is based on the International Residential Code, there are specific requirements for fire safety outlined in section R302. Your building dept. should be able to tell you what is needed if you vent through the attic space above the garage.