When I plug-in an USB stick (FAT) into my Centos Linux machine, all files have the executable bits set. After having copied the directory structure to my hard disk I remove the executable bits recursively just from the files and keep those on the directories with following command:
chmod -R -x+X *
Explanation:
-R– operate recursively-x– remove executable flags for all users+X– set executable flags for all users if it is a directory