Upvote:2
You do not need a transit visa if you do not intent to leave the airport and is within 24 hours.
Since, Malindo and Lionair are partners, they will usually allow you to check through the bags even if its different PNR (experienced) and you will have to collect the boarding pass from the airport transfer counter.
Even if the check through is not allowed, you can approach transfer counter airside to get the bags transferred to your flight for free. I have done this for Srilankan Airlines to Malaysian Airlines.
Both flights operate from same terminal http://www.klia2.info/airlines/. Malindo gates may be on the satellite building, so you may have to catch the airside train to reach it.