The 24-year-old, in his third spell at the club, has scored seven goals in his 17 appearances for the Cumbrians since coming back in September.
Carlisle manager Greg Abbott said: "Joe has done a good job for us and we know exactly what we're going to get.
"He causes problems and he's brave, and he has got us some really important goals. We think he still has more to show because he's getting better as he spends more time out on the pitch.
"He's getting games and he's enjoying himself up here, and we think this has been a move which has been of benefit to all concerned."
Garner first joined Carlisle on loan when he was at Blackburn in 2007 and made the move permanent in a £140,000 deal the following summer before sealing a £1.14million move to Nottingham Forest in July 2008.