If the freezer section is working satisfactory, you more than likely do not have a freon leak. Refrigerators and freezers contain very little freon and it doesn't take much of a leak for it to stop being cold, plus freon has very little odor.
If you can get to the cold coils in the freezer section (you'll probably have to remove a cover), take an old spray bottle (windex or such) and fill it with peroxide. Spray all the surfaces and coils until wet. Let it all dry (don't wipe it up) and see if this helps. (You may have to do it twice) Peroxide is the greatest in eliminating odors! ....Hope this helps!
