The noexec mount option specifies that the filesystem cannot contain executable binaries. Since the /tmp filesystem is only intended for temporary file storage, set this option to ensure that users cannot run executable binaries from /tmp.
Edit the /etc/fstab file and add noexec to the fourth field (mounting options) for the /tmp partition. See the fstab(5) manual page for more information. Run the following command to remount /tmp: # mount -o remount,noexec /tmp