Linked by Thom Holwerda on Mon 29th Jan 2018 23:17 UTC
Windows

Microsoft has released an update that disables Intel's microcode Spectre mitigations.

Intel has reported issues with recently released microcode meant to address Spectre variant 2 (CVE 2017-5715 Branch Target Injection) - specifically Intel noted that this microcode can cause "higher than expected reboots and other unpredictable system behavior" and then noted that situations like this may result in "data loss or corruption". Our own experience is that system instability can in some circumstances cause data loss or corruption. On January 22, Intel recommended that customers stop deploying the current microcode version on affected processors while they perform additional testing on the updated solution. We understand that Intel is continuing to investigate the potential effect of the current microcode version, and we encourage customers to review their guidance on an ongoing basis to inform their decisions.

This whole thing is a mess.

Thread beginning with comment 653329
To read all comments associated with this story, please click here.
No solution
by Treza on Tue 30th Jan 2018 00:29 UTC
Treza
Member since:
2006-01-11

After being aware of the issue for 6 months, it seems now clear that either there is no microcode solution able to solve the problem, or the solution would compromise performances so much that Intel would have to pay back customers.

I'm afraid that Intel won't really fix the issue in current chips, a bit like with the old Pentium FDIV bug, they will insist, at first, that it won't be a real problem in most situations.

Reply Score: 8

RE: No solution
by dionicio on Tue 30th Jan 2018 00:39 in reply to "No solution"
dionicio Member since:
2006-07-12

Could Be Worst, Treza. At this moment wouldn't like to consider the possibility of the breach allowing micro-code corruption.

Reply Parent Score: 1

RE: No solution
by Megol on Tue 30th Jan 2018 14:12 in reply to "No solution"
Megol Member since:
2011-04-11

After being aware of the issue for 6 months, it seems now clear that either there is no microcode solution able to solve the problem, or the solution would compromise performances so much that Intel would have to pay back customers.

I'm afraid that Intel won't really fix the issue in current chips, a bit like with the old Pentium FDIV bug, they will insist, at first, that it won't be a real problem in most situations.


They can't and they shouldn't. Why?

IT ISN'T A BUG.

The FDIV problem was a bug: optimization of a hardware table that failed for some numbers.

F00F was a bug: failure to detect illegal opcode that meant the hardware could reach a state it shouldn't - resulting in halting execution.

IMO the Meltdown thing is a bug (not all think so).

This isn't. The processor does what it was designed to do, what it is documented to do in a way that is documented. No bug.

And it's an industry wide problem. Problem - not bug.

Reply Parent Score: 2

RE[2]: No solution
by CaptainN- on Tue 30th Jan 2018 15:25 in reply to "RE: No solution"
CaptainN- Member since:
2005-07-07

It's a design flaw, which in software at least, can still be called a bug. It does do what it was designed to do, but due to an oversight, it has a security problem that no one noticed for a long period of time.

Reply Parent Score: 4

RE[2]: No solution
by Treza on Tue 30th Jan 2018 21:16 in reply to "RE: No solution"
Treza Member since:
2006-01-11

The processor does what it was designed to do


Oh, if it is not a bug, I guess it is a feature !

Reply Parent Score: 4

RE[2]: No solution
by viton on Tue 30th Jan 2018 21:50 in reply to "RE: No solution"
viton Member since:
2005-08-09

IMO the Meltdown thing is a bug (not all think so).

This isn't. The processor does what it was designed to do, what it is documented to do in a way that is documented. No bug.


Not sure if you're trolling or not.
Access to high privileged kernel-mode memory from unprivileged usermode process is not documented and it is definitely _not_ a designed behaviour.

Please, show me the description of this "feature" in architecture reference manual.

Edited 2018-01-30 22:05 UTC

Reply Parent Score: 7

RE[2]: No solution
by aaronb on Wed 31st Jan 2018 13:44 in reply to "RE: No solution"
aaronb Member since:
2005-07-06

The separation of user space and kernel space has been a specified feature (Privilege levels) since the Intel 386 (possibly earlier) on the x86 architecture. Meltdown blurs the line between the two as speculative execution seems to be able to speculate with kernel space data from user mode processes and allows the speculated kernel space data to be leaked to user space. If the leaking did not occur the feature would be working as designed.

In my opinion this is a bug that requires software mitigation for current Intel CPUs and hopefully the next generation of Intel CPUs will not be susceptible to Meltdown.

This issue seems to have taken the tech community by surprise, needs to be addressed as quickly as possible due to the severity and is challenging to fix.

Reply Parent Score: 3