Loss of cellular service or ability to use Touch ID after updating to iOS 8.0.1 on iPhone 6 or iPhone 6 Plus

We have a workaround for you if you have an iPhone 6 or iPhone 6 Plus and you lost cellular service and Touch ID functionality today after updating to iOS 8.0.1. You can reinstall iOS 8 through iTunes by following the instructions below. We are also preparing iOS 8.0.2 with a fix for the issue, and will release it as soon as it's ready in the next few days.

by via Apple - Support - Most Recent - iPhone