261–270 of 298 posts
Earlier quoted context omitted.
Does this also apply to vsyscall's being emulated? Will this mean that older static binaries will no longer run? or just suffer a penalty as well?
This topic got me to look at the vDSO for my own machine so I wrote a short Perl program to dump your kernel's vDSO. https://pastebin.com/UnQX5U1f
Earlier quoted context omitted.
Why are people insisting this affects cloud computing market? I am not sure if this bug is absolutely limited to cloud instances.
Because this bug allegedly affects hypervisors/VMs.
Earlier quoted context omitted.
Sounds like servers handling lots of small UDP packets would be hit pretty hard.
Applications like this where the syscall overhead (and latency) starts to be a significant factor in processing time and latency have moved to userland drivers anyway: DPDK for 10-100 Gbps networking: https://dpdk.org/ SPDK for NVMe storage: http://www.spdk.io/ The queuing and balancing stuff the kernel does makes sense for spinning rust harddisks and residential networking, but when the underlying hardware is so fas…
I would personally think that is worse, though please correct me if I'm wrong. The userland driver will run with an isolated PT like any other userland process won't it? If so, it will suffer the same slowdown that every other process now has every-time it has to communicate with the kernel, which I would think would be a lot for a driver.
At the meta level this is just a special case of "complexity is evil" in security. CPUs have been getting more and more complex, and the relationship between complexity and bugs (of all types) is exponential. Each new CPU feature exponentially increases the likelihood of errata. A major underlying cause is that we're doing things in hardware that ought to be done in software. We really need to stop shipping software…
Out of curiosity, which parts of .NET bytecode do you believe to be "too far abstracted from the hardware"? The object model, certainly, but you don't need to use that. On the other hand, the basic instruction set for arithmetic and pointers seems to be on the same abstraction level as WebAssembly to me.
Actually doing a big of searching I think you originally could but for some reason they removed it.
Earlier quoted context omitted.
Okay so take this bug for example. It seems to have to do with the CPU speculatively performing a load before checking that it won't generate a page fault due to user code trying to access kernel memory. Say you get rid of process isolation, etc. How do you protect kernel code from user code? You can't do any sort of static analysis I'm aware of that'll still allow you to run C code (which let's you manufacture point…
> And if you insert dynamic checks instead, you're talking about turning each memory access into many (memory accesses that in a modern CPU are hidden by the TLB). You only have to check that the memory address is not negative (kernel pointers are negative on x86-64). No extra memory access needed. > You can't do any sort of static analysis I'm aware of that'll still allow you to run C code (which let's you manufactu…
You could still toss a lot: virtualization, complex multi-layered protection modes, address remapping, and essentially every hardware feature that exists to support legacy binary code. All deprecated instructions and execution modes could go, etc.
Finally you would maintain the benefit of architecture flexibility. Switching from x86 to ARM, etc., would be easy.
Earlier quoted context omitted.
How can you request a citation about things relating to possible intelligence agencies efforts with a straight face? It's literally their job to make sure such material doesn't exist or sees the light of day if it does. It's not exactly publicly-funded science now, is it? You request a proof that's impossible to procure. Are you now gonna claim the lack of this proof supports your thesis?
Yes? Because acting on pure unvarnished unburdened by critical thinking speculation is not a good idea?
Was the connection with speculative execution already being discussed openly? I know about https://cyber.wtf/2017/07/28/negative-result-reading-kernel-... , but not about anything between that and 28 Dec suggesting someone made it work and that's the reason for KPTI. If it wasn't in the open, seems...not ideal embargo-wise for AMD to leak it there. Though no one's in that thread complaining about the disclosure, so m…
Earlier quoted context omitted.
I've heard you can schedule big sales all the time and then regularly cancel them unless something goes wrong. Apparently there is no rule against insider canceling.
That's not true. Changing a stock sale plan in any way is considered insider trading. The window has nothing to do with whether it's legal or not. It's only used a risk mitigation and is up to company policy. https://corpgov.law.harvard.edu/2013/02/05/rule-10b5-1-plans...
Earlier quoted context omitted.
You say "do you have proof?". But nobody can have proof beforehand . That's how these things always go -- something is done under cover and later (usually much later) somebody uncovers it and shows it to the world. Why do you ask of a proof that can't possibly be in the spotlight right now? Many historical facts have been denied and met with skepticism and mockery until they have been proven to be indeed facts. Why i…
Ok you lost me at “future historical fact”. Again that is a fancy way of saying pure speculation. No I don’t know for a fact that the NSA didn’t order Intel to build a buggy ME into all its processors. I can’t prove that it didn’t happen. And maybe your speculation will turn out to be right. I am arguing that my speculation that this was incompetence is significantly more likely to be correct than your speculation of…
Judging by other activities of the intelligence agencies and working with pure speculation -- not hiding from these words, you are correct by calling it that -- I still think it's much more likely they commissioned the Intel ME.
You mention critical thinking in another comment. Critical thinking, the way I apply it, also requires a historical context to be applied to the situation one is analyzing. Agencies have been doing pretty shady stuff and some of it has been uncovered for the entire world to see.
Critical thinking, the way I apply it, says that the odds are there is a foul play. I merely wish you to recognize that this is the more likely scenario than a bunch of coincidences and/or people supposedly making the ME to serve data center sysadmins -- btw many of those sysadmins, including on several threads here in HN, said they never used the ME and named a plethora of other tools.
Obviously I am not trying to change the way you think in general. I believe we can both agree that none of us knows for sure. The human brain's strength is to work with many variables and be able to impose some order in the chaos by pattern recognition and using historical info. I am not gonna deny this can lead to people drawing awfully misguided conclusions sometimes -- and I've been guilty of that as well! -- but it's the best we have, especially having in mind what tiny imperfect brains we have to work with.
Everything I can name are circumstantial evidence. I accept that. It's the nature of the area. Intelligence data isn't easy to come by.
Earlier quoted context omitted.
If your allegation is true, that would seem to be very illegal.
I've heard you can schedule big sales all the time and then regularly cancel them unless something goes wrong. Apparently there is no rule against insider canceling.