cancel
Showing results for 
Search instead for 
Did you mean: 

[MAIN\MERGED] Intel Skylake & Kaby Lake Hyperthreading Bug

pepper_chico
Level 7
It has been confirmed that Intel's Skylake/Kaby Lake hyper-threading can present serious issues that can be fixed by a BIOS/UEFI update that targets Intel processor errata KBL095, KBW095 or the similar one for Kaby Lake processor.

Any plans for such update to come? On Kaby Lake it seems the most safe route at the moment is to simply disable hyper-threading until ASUS provides a new BIOS that addresses this. On Skylake there's the option on ArchLinux side, for example, to install extra/intel-ucode to get microcode updates since there's a fix in revision 0xb9/0xba and later. Windows doesn't have a microcode update for this yet, afaik.

Source: https://lists.debian.org/debian-devel/2017/06/msg00308.html
85,282 Views
133 REPLIES 133

AKBAAR wrote:
no need to panic, just update your CPU Microcode to latest version. and good thing there is an application that does it for you automatically.

Well,

I use this tool to update my CPU Microcode Automatically to latest which is Version BA !
Enjoy

http://www.win-raid.com/t154f16-Tool-Guide-News-quot-UEFI-BIOS-Updater-quot-UBU.html

65611

That only works for some cpu's and ones with sidestepping 3 and either model 78 or 94, most aint that.
processors must
be either model 78 or 94, and stepping 3, for the intel-microcode fix
to work:

Daytrader wrote:
That only works for some cpu's and ones with sidestepping 3 and either model 78 or 94, most aint that.
processors must
be either model 78 or 94, and stepping 3, for the intel-microcode fix
to work:


Any reputable sources? Intel would be sufficient.

Intel replied this to me earlier today:

"Intel: The unexpected behavior related to Hyper-Threading Technology is for the systems with Linux* Debian* OS only. Regards. RS"
If we can't live together, we are gonna die alone.

@Exogorth

I'm not sure about that. My understanding - from reading all the same online stuff about this bug that's available to everyone else - is that it can corrupt data inside processor L2/L3 cache. This bad data might by passed to RAM, written to storage (NVRAM/HDD), passed along to other processing hardware, etc. So yes it's possible it could wreck the running OS or running softwares (games) or cause faults in other hardware (especially GPUs) ... but the conditions needed to manifest this bug are so very specific that it's very difficult to reproduce on demand without very specific system tools, and the effects of bad data are basically entirely unpredictable, you could not notice a briefly-seen texture in your fps game that had a colour value off by a few bits, you could just as easily overwrite critical things in memory or SSD/HDD with an address value that's off by a few bits, you have a few stray bytes of bad data stored on your system and waiting to be opened/executed and these could cause a typo in a text document as easily as a critical BSoD fault in a driver library.

@Voidburn

www.win-raid.com is a fairly reputable source. I've executed stuff from the site before without issue. In fact, those people who complain win-raid stuff broke their systems are typically responsible for breaking their systems themselves. Override your firmware and driver components at your own risk, lol.

That being said, I fully agree that strange/unnecessary executables (especially those downloaded from ".ru" types of sites) must be treated as hostile invaders until proven otherwise, lol.


@AKBAAR
Daytrader wrote:
That only works for some cpu's and ones with sidestepping 3 and either model 78 or 94, most aint that.
processors must be either model 78 or 94, and stepping 3, for the intel-microcode fix to work:

+1 what @Daytrader said: your workaround appears to work on your system (congrats!) ... but it won't work on every system affected by this bug. Not everyone runs an i7-6700K Version BA part like yours.
"All opinions are not equal. Some are a very great deal more robust, sophisticated and well supported in logic and argument than others." - Douglas Adams

[/Korth]

Korth wrote:



@AKBAAR

+1 what @Daytrader said: your workaround appears to work on your system (congrats!) ... but it won't work on every system affected by this bug. Not everyone runs an i7-6700K Version BA part like yours.


Naaah it works for all CPU generations. even kabylakes and canonlake the new ones too.

Korth wrote:
the conditions needed to manifest this bug are so very specific that it's very difficult to reproduce on demand


At the very least that also applies to the problem I have been experiencing for the last 2 years.

Daytrader wrote:
That only works for some cpu's and ones with sidestepping 3 and either model 78 or 94, most aint that. processors must
be either model 78 or 94, and stepping 3, for the intel-microcode fix to work:


/home/xxxxx $ grep -E 'model|stepping' /proc/cpuinfo | sort -u
model name : Intel(R) Core(TM) i7-6700K CPU @ 4.00GHz
model : 94
stepping : 3

Both the SKYL 6700K CPUs (circa late 2015) I have are model 94 and stepping 3.

https://rog.asus.com/forum/showthread.php?94263-Intel-Skylake-and-Kaby-Lake-Hyperthreading-Bug

https://rog.asus.com/forum/showthread.php?94262-BIOS-update-for-broken-Intel-s-Skylake-Kaby-Lake-hyp...

Lets try to keep these threads centralized so no one misses the updates when they finally arrive.
I'd like to deploy my troops in her country.

Well,

I use this tool to update my CPU Microcode Automatically to latest which is Version BA !
Enjoy

http://www.win-raid.com/t154f16-Tool-Guide-News-quot-UEFI-BIOS-Updater-quot-UBU.html