Intel's Skylake & Kaby Lake generation CPU proved hyperthreading valid, has serious bug that leads to data loss and program error

Intel's 6 th generation Core processor "SkylakeSeries and 7th generation Core processor "Kaby LakeIt is pointed out that there is a microcode bug with possibility to cause data corruption and loss if the Hyper Threading function is used for the CPU of the series, unpredictable error occurs in the system.

[WARNING] Intel Skylake / Kaby Lake processors: broken hyper-threading
https://lists.debian.org/debian-devel/2017/06/msg00308.html

Intel's Skylake and Kaby Lake CPUs have nasty microcode bug • The Register
https://www.theregister.co.uk/2017/06/25/intel_skylake_kaby_lake_microcode_bug/

Critical Flaw In Intel Skylake And Kaby Lake HyperThreading Discovered Requiring BIOS Microcode Fix | HotHardware
https://hothardware.com/news/critical-flaw-in-intel-skylake-and-kaby-lake-hyperthreading-discovered-requiring-bios-microcode-fix

There is a report that there is a microcode defect in the Skylake generation and the Kaby Lake generation CPU in the Debian project. This defect is "Hyper Threading"Function concerning the function of the hyperthreading function ON, it proves to bring unpredictable system operation to Debian system, warning that there is the possibility of data corruption and data loss besides system / application error It is being done.

A bug in the microcode of this skylake generation and the CPU of the Kaby Lake generation is that a short loop occurs in the register when hyperthreading is effective and the system or application behaves erroneously, the data is damaged or missing It is a serious matter to do. further,This defect affects not only Linux such as Debian, but also any OS such as Windows and macOSIt is said to be things. According to the Debian project that reported bugs, it is difficult to identify potentially affected users, and it is pointed out that all users of Skylake generation and Kaby Lake generation CPU users need to take measures.


In addition, it is recommended that the user disable the hyperthreading function in BIOS / UEFI in order to avoid the risk of system error or data miss while the bug-fixed microcode update is provided It is being done. For models that do not have hyper threading like the Core i 5 series for desktops, and CPUs of generations prior to the 5th generation Core processor "Broadwell", they are not affected by this bug.

The Skylake generation CPU and the Kaby Lake generation CPU are both active, and it is possible that the influence may occur in any OS, so it seems that the scope of target users to be countermeasured can be said to be quite wide. In addition, Skylake · Kaby Lake subject to bug is equipped with a new high-end CPU "Core i 9"Series including Core-X series are included.