I live in an apt that has an enclosed hallway. It fucking stinks

Also I don't own it so I can't replace the door or insulate further unless he won't notice I insulated the walls

Local hardware store should have rolls of door seal and a rubber sweep. That would be a good start.

>>937694
Yep. door seal tape is gonna be your go to. If door is an interior hollow core door, wouldn't suggest a door sweep. you should be able to get away with seal tape for the sides and top and a draft snake or rolled up towel to seal the bottom.
Honestly, just rat out your roommates to the landlord. Landlords fucking HATE smokers, discolors walls, ash ruins carpets, they tend to litter butts everywhere, and the smell is expensive to remove. Like tear out drywall and insulation and replace and repaint expensive.
So if he wants to keep them, you should ask to pay less rent because of low air quality, if not, you get rid of smokers.