What’s Vulnerable › Vulnerabilities

CVE-2021-47112: x86/kvm: Teardown PV features on boot CPU as well

• Severity: medium (CVSS 5.5 v3.1)
• Exploited in the wild: not listed in CISA KEV
• EPSS: 0.2% probability of exploitation in the next 30 days
• Public exploit or detection template: none known
• Published: 2024-03-15 · updated 2026-08-04

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.

Affected products

• Linux kernel: before 5.4.125; from 5.5 before 5.10.43; from 5.11 before 5.12.10; 5.13-rc1 — fixed in 5.10.43, 5.12.10, 5.4.125

How to fix

Upgrade to a fixed version: Linux kernel 5.10.43, 5.12.10, 5.4.125. Check the vendor advisory for mitigations.

References

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

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