SWAPGS — CVE-2019-1125

SWAPGS, aka Grand Schemozzle, is a variant of Spectre v1, where conditional branches in the entry paths which contain a SWAPGS instruction (interrupts and exceptions) can be mis-speculated which results in speculative accesses with a wrong GS base.

The Linux kernel documentation has a nice documentation about the nitty-gritty details.

Linux had a fix released the 6th August 2019, FreeBSD as well. The day after, it landed in RHEL.

OpenBSD fixed it, as well as Microsoft’s Windows, the 9th of August 2019.