Linux 4.4 & 4.9 Kernels Get Back-Ported SWAPGS Protection

Greg Kroah-Hartman issued the Linux 4.4.189 and Linux 4.9.189 LTS kernels on Sunday morning that address the new Spectre V1 "SWAPGS" variant mitigations.

SWAPGS was publicized earlier this week and since the launch-day mitigations for Linux 5.3 Git, the SWAPGS speculative protection has been making its way back to the various supported Linux kernel stable trees. This additional SWAPGS mitigation protection does take another minor performance hit for Intel CPUs going back to Ivybridge.

For those still on the older LTS series, Linux 4.4.189 and Linux 4.9.189 are out and aside from various other small fixes, the main addition to these point releases is the SWAPGS mitigations by default for affected Intel CPUs.