Intel® FPU Speculation Vulnerability Confirmed

Earlier this month, Philip Guenther (guenther@)committed(to amd64 -current) a change from lazy to semi-eager FPU switchingto mitigate against rumored FPU state leakagein Intel(R) CPUs.

Theo de Raadt (deraadt@) discussed this in hisBSDCan 2018session.

Using information disclosed in Theo's talk,Colin Percivaldeveloped a proof-of-concept exploit in around 5 hours.This seems to have prompted an early end to an embargo(in which OpenBSD was not involved), and theofficial announcementof the vulnerability.