[Info-vax] Intel junk...Kernel-memory-leaking Intel processor design flaw forces Linux, Windows redesign

[Alan Browne]

On 2018-01-05 09:15, DaveFroble wrote:
> Jan-Erik Soderholm wrote:

>> Becuse the designers, for performance reasons, has mapped kernel memory
>> into the user process address space and relies on the OS to check
>> protection before any kernel memory (or code) is accessed.
>>
>> The issue with the current issues is that the hardware (the CPU) does
>> these accesses in hardware "under the hood" without control by the OS.
>>
>> If you map your kernel memory in another way that uses the hardware
>> protection facilities, you are (as I understand) safe, at the cost
>> of worse performance to switch between user and kernel mode.
>>
>>
> 
> As I wrote, someone dropped the ball on this one.
> 
> Speculative execution is part of the HW, not software.  It appears the 
> HW doesn't follow it's own rules.  Or, perhaps I don't actually 
> understand the problem?

At least as well as I do.  These are very complex mechanisms and 
complexity is usually where you're most likely to get problems.

In this case the h/w implementation didn't reflect the design goal.

This means intel had very poor design review and abysmal testing of 
security features.

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