The 20-year-old from Ayrshire joined Clermont Auvergne in the summer of 2011, but his progress has been curtailed by a knee injury.
Bennett, who came through the Warriors elite development system, told glasgowwarriors.org: "It's hugely exciting for me to have the opportunity to return to Glasgow."
He added: "It's always been my ambition to play professional rugby for the Warriors, and it was a massively tough decision to leave for Clermont 18 months ago.
"There has been real progress at Glasgow on and off the field since then, and it's a great environment to be coming into."
Glasgow head coach Gregor Townsend was pleased to sign the former Scotland Under-18 and Under-20 centre.
Townsend said: "Mark has the potential to become a very important player for Glasgow Warriors.
"It's further good news for the club and for Scottish rugby in general to be bringing Mark on board.
"He's here for the rest of the season, and, as with any player who comes in on loan, we'll be constantly assessing if and how they might fit into our plans in the longer term."