I just encountered this for the first time. CTRL+C & CTRL+V would not copy and paste. I could see one burning out or something, but both control keys are not working. Tried a reboot and it didn't help.
I have a ps2 mouse and keyboard, both plugged into a USB adapter. Just unplugged the USB adapter and replugged it in and the keys work normal again. Seems odd that resetting the USB connection resolved it and a restart would not have fixed it, but at least it was a simple fix. Hope that helps someone else.