World number one Chong Wei beat South Korea's Lee Hyun-il 21-19 21-18 and was joined a couple of hours later by China's world and Olympic champion Lin who edged out Japanese seventh seed Kenichi Tago 21-18 21-17.
The final will be a repeat of the memorable world championship at Wembley Arena last August when Lin saved two match points before beating Chong Wei in three sets.
Chong Wei, seeking a hat-trick of title wins in the All England tournament, made errors on the way but eventually outlasted his eighth-seeded opponent to the joy of a large Malaysian contingent in the big crowd.
He told reporters: "My hand was a little bit painful. I woke up with it this morning but it will be fine for tomorrow."
The women's singles produced another mighty feat from world champion Wang Yihan who came from behind to beat Chinese compatriot Wang Shixian 20-22 21-18 21-18 in an 85-minute marathon.
In Friday's quarter-finals Wang Yihan had saved four match points before edging out Denmark's Tine Baun in another tough three-setter.
In Sunday's final Wang will meet seventh-seeded compatriot Li Xuerui who beat Taiwan's Tai Tzu Ying 19-21 21-16 21-10.