A leaking attic can be very dangerous and it can cause damage to the whole building as a whole gradually. To stop the erosion, one must immediately take assistance of a professional contractor. He should be able to detect the exact point of erosion. Often it a spot which is constantly impacted by hail or heavy rains.
There can be shingles, which are damaged or broken and needs a replacement. Any cracks or leakages can be plugged in as well. However, if there is seepage in the attic roof all together, it is obviously advisable to completely change the roof all together. Considering the material of the roof, which might be tiles or iron, it is ideal to take professional help and spend some more money if required to fix it.
The professional would take care of all the vents and damages on the roof through sealing the gaps or changing the material all together.