Not what I meant.No spreading FUD, please.
Meltdown was discovered independently by Jann Horn from Google's Project Zero, Werner Haas and Thomas Prescher from Cyberus Technology, as well as Daniel Gruss, Moritz Lipp, Stefan Mangard and Michael Schwarz from Graz University of Technology. The same research teams that discovered Meltdown also discovered a related CPU security vulnerability now called Spectre
Project Zero was the first to discover and inform CPU makers about these problems (which they did in June). The issue wasn't made public to give CPU manufacturers time to fix it.
However, it leaked some time before the planned patch launch date.
There's a good article about this situation:
"It's true that AMD didn't actually reveal the details of the flaw before the embargo was up, but one of the company's developers came very close. Just after Christmas, an AMD developer contributed a Linux patch that excluded AMD chips from the Meltdown mitigation. In the note with that patch, the developer wrote, "The AMD microarchitecture does not allow memory references, including speculative references, that access higher privileged data when running in a lesser privileged mode when that access would result in a page fault.
For a company operating under an embargo, with many different players attempting to synchronize and coordinate their updates, patches, whitepapers, and other information, this was a deeply unhelpful act."
The patch note is from Dec 26. I've seen some forum discussions about it on 27-28 already.