Canonical has rolled out Spectre Variant One and Spectre Variant Two mitigation to their proposed repository with updated kernels for Ubuntu 14.04 LTS / 16.04 LTS / 17.10. These kernels with IBRS and IBPB added in will be sent down as stable release updates next week…

Source: Phoronix – Ubuntu Preparing Kernel Updates With IBRS/IBPB For Spectre Mitigation