CVE-2021-47112 Information

Description

In the Linux kernel the following vulnerability has been resolved:

x86/kvm: Teardown PV features on boot CPU as well

Various PV features (Async PF PV EOI steal time) work through memory shared with hypervisor and when we restore from hibernation we must properly teardown all these features to make sure hypervisor doesn’t write to stale locations after we jump to the previously hibernated kernel (which can try to place anything there). For secondary CPUs the job is already done by kvm_cpu_down_prepare() register syscore ops to do the same for boot CPU.

Reference

https://git.kernel.org/stable/c/7620a669111b52f224d006dea9e1e688e2d62c54 https://git.kernel.org/stable/c/38b858da1c58ad46519a257764e059e663b59ff2 https://git.kernel.org/stable/c/d1629b5b925de9b27979e929dae7fcb766daf6b6 https://git.kernel.org/stable/c/8b79feffeca28c5459458fe78676b081e87c93a4