Contributed by rueda on from the speculation-no-more dept.
Earlier this month, Philip Guenther (guenther@) committed (to amd64 -current) a change from lazy to semi-eager FPU switching to mitigate against rumored FPU state leakage in Intel® CPUs.
Theo de Raadt (deraadt@) discussed this in his BSDCan 2018 session.
Using information disclosed in Theo's talk, Colin Percival developed 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 the official announcement of the vulnerability.