When I got home from work on Friday I noticed there was a 4' line of discoloration on the ceiling of my kitchen (it had been raining most of Thursday/Friday). I went up into the attic and couldn't find anything, then on Saturday went up on the roof and everything looked normal there as well. Today I went back up into the attic as it was raining, and found the leak: part of one of the sheets of plywood had splintered in the middle (from hail last week I'm guessing?), and there was a steady drip of water coming down from that. Is this something I can fix from the inside? or do the shingles/barrier need to be replaced in that area from the outside, even if everything looks normal (to my untrained eye, anyway)?