Follow this link to post #143. This will fix your wifi tether. Works on my AT&T Note 2 and S3.
http://forums.androidcentral.com/sprint-galaxy-s-iii/224652-wifi-tether-jellybean-here-confirmed-6.html
Here is the link to download the wifi tether TrevE:
WifiTether_TrevE_Mod_11_22_2012.apk | by...