Over dosing on chlorine frequently accelerates the liners ageing. Sun damage around your pool water line is also a contributing factor. The sun bakes on dirt, scum, and organic matter on to your pool liner which actually dries your liner out over time. This problem is best alleviated by cleaning above the waterline with a vinyl liner cleaner.
Liner Repair: If your pool liner is in decent condition and is not old, then there is a good chance that it can be repaired.