Following Monday’s public disclosure of the “Training Solo” security disclosure for this set of issues affecting multiple generations of Intel processors, new Intel CPU microcode has been released for Linux users as part of the mitigation process.
As noted in an update to the Training Solo article, the Linux kernel mitigations were merged within several minutes of the embargo lift. This includes the Linux kernel changes for Indirect Target Selection (ITS) as well as Intra-mode Branch History Injection. Monday then brought the publishing of new Intel CPU microcode binaries with the necessary microcode changes.
The Intel Microcode 20250512 release brings updates from the newest Core Ultra 200V “Lunar Lake” processors back through 8th Gen Intel Core CPUs and then on the Xeon server processor side from the newest 6th Gen Xeon Scalable back to 2nd Gen Xeon Scalable and other processor series like the Xeon E-2300 series, Xeon D-2700, and others. This is also the first time seeing microcode updates for Arrow Lake U / S / HX / H, Granite Rapids AP/SP, and Lunar Lake as part of the Linux CPU microcode collection.
It’s a big set of updates for what Intel classifies via their security advisory system as SA-01153, SA-01244, SA-01247, and SA-01322.
The new Intel CPU microcode updates are availavble for download from the Intel GitHub repository. Benchmarks of the new Linux kernel patches and Intel CPU microcode updates will begin soon to look for any performance changes.
