For those who are unlocked, rooted, and have a custom kernel, here are the instructions on how to install the stock unsecured kernel. You need the unsecured kernel because it allows root access.
Credit to dsb9938 of XDA who is the creator of the Cubed Kernel for the DNA (here's the link to that thread [KERNEL]Droid DNA Cubed Kernel v2.2.1[12.22.12]New Governors, various fixes - xda-developers)
Also, dsb9938 says you should go through this process if you're switching from his kernel to another kernel (including the stock kernel) because the install of his kernel deletes some stock files.
1. Download this file Dev-Host - DNA.Stock.Kernel.zip - The Ultimate Free File Hosting / File Sharing Service
2. Unzip it and place DNA.Stock.Kernel.Modules.zip somewhere on the phone where you can find it in recovery. Leave boot.img where it is.
3. Boot into fastboot (reboot, hold volume down, select fastboot).
4. Go to the folder where boot.img is then hold shift and right click to open the command prompt.
5. Type: fastboot flash boot boot.img
6. Close command prompt and reboot to recovery (hold volume down, select recovery).
7. Install DNA.Stock.Kernel.Modules.zip