You just need to install the kernel devel as the same version of your kernel OS.
# yum install kernel-uek-devel-'uname -r' kernel-headers
Then run your command
./VBoxLinuxAdditions.run
Reboot.
If you get the /media/sf_sharedFolder/: Permission denied Then add yourself to the vbox group
# sudo adduser oracle vboxsf # sudo usermod -aG vboxsf oracle 