91–100 of 205 posts
I was under the impression that Ubuntu would automatically revert to last good kernel of the new one fails to boot. Was I mistaken?
This arch/x86/events/intel/ds.c fix is unlikely to have rendered too many things unbootable. I missed ds.c entirely when doing the original implementation. I can't fault the nice folks at Canonical for mis-merging a tiny hunk like this. It really only affects pretty specific hardware anyway.
What hardware does it effect?
it's the fault of Intel, why don't they recall all the CPU? just like vehicle company
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>Would this entire Meltdown/Spectre thing count as the biggest mess-up of computing history? When yesterday the PoC repo was posted here, the spy.mp4 demo video gave me some chills. It must be up there amongst the greats, probably with the "halt and catch fire" op code. Normally they just patch this stuff with microcode and never really tell anybody, this time that won't work. I'm not entirely convinced it was a mist…
I think it's absolutely unreasonable to imply that this was intentional. Besides the massive amount of complexity these systems have, there are plenty of "legitimate" places to hide backdoors, instead of in a performance architecture decision. Keep in mind that whatever "evil agencies" would have asked for this would most likely find themselves vulnerable, and nobody would sign off on. I do agree, however, the "secur…
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AFAIK worse case you should be able to select the previous kernel in grub2 upon reboot. It just hangs after grub on this (bad) kernel I think...
Yeah but if you have a couple of hundred machines that aren't booting.... That's pretty worst case.
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Actually, it is more like that someone can throw a rock through a car window and then compromise the car door lock. Or, probably more accurately, that a hitchhiker can knock you out of the car, and drive off with it. Spectre/Meltdown ONLY is an issue if you run some untrusted code on your system. If you avoid this, there is not problem. Yes, we like to be able to run untrusted code (such as in a web browser / javascr…
I'm with you on the untrusted code bit, which is why I think unmapping the kernel should be restricted to untrusted processes. Then it only applies to your browser, the KVM/qemu instances or whatever runs untrusted code. Yup, this will hit the EC2/etc users hard, but those people have already IMHO given up on absolute performance by putting themselves in shared environments where bad neighbor syndrome can already hit…
Your idea of black/white listing processes might bubble up as a solution in some scenarios. Perhaps it could be pledge-like; if you're savvy enough, try implementing it, or fleshing out the details.
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>Would this entire Meltdown/Spectre thing count as the biggest mess-up of computing history? When yesterday the PoC repo was posted here, the spy.mp4 demo video gave me some chills. It must be up there amongst the greats, probably with the "halt and catch fire" op code. Normally they just patch this stuff with microcode and never really tell anybody, this time that won't work. I'm not entirely convinced it was a mist…
Yeah ME is a scary thing also. WRT Linux, well my Xubuntu 16.04 (Xenial) is on 4.10 and no new kernels are available to ma ATM. So if they're going to patch my OS, that's probably going to be a backport to that version, not the latest release integrated to my OS version. I guess that's what caused this bug too, although I admit I only skimmed the conversation linked.
See https://wiki.ubuntu.com/SecurityTeam/KnowledgeBase/SpectreAn...
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I think that title is currently held (deserved or not) by null pointers. Tbh it’s not the most meaningful of statements, but it’s food for thought.
A null pointer doesn't hold a reference, though.
Or, to put it another way, I have no clue to what you're referring--what do references have to do with "The Billion Dollar Mistake"[0]?
[0]: https://en.wikipedia.org/wiki/Tony_Hoare#Apologies_and_retra...
EDIT: my apologies, that joke was actually pretty good.
any report of windows update messing with the bios rendering motherboard non bootable (powers on , but no post, not even an error beep)
For AMD chips, yes. Yesterday Microsoft announced they were suspending rolling out updates to certain AMD chips because it was resulting in non-bootable systems. I didn't read the technical details so I can not say whether it was specifically BIOS-related. Both a total non-booting state and BSODs were mentioned in the article I saw (from general press, so might have been garbage, sorry).
So it sounds like it was probably specific chipsets and not CPUs, but who knows.
[1] - https://www.engadget.com/2018/01/09/microsoft-halts-meltdown...
[2] - https://support.microsoft.com/en-us/help/4056892/windows-10-...