CVE-2021-47110

x86/kvm: Disable kvmclock on all CPUs on shutdown

HIGH
7.1
CVSS Score
Published: March 15, 2024 at 08:14 PM UTC
Updated: June 17, 2026 at 04:16 AM UTC
1 product affected across 1 vendorLinux Kernel

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Severity
HIGH7.1
Exploit prediction
EPSS 0.2%
SSVC
No known exploit

Description

In the Linux kernel, the following vulnerability has been resolved: x86/kvm: Disable kvmclock on all CPUs on shutdown Currenly, we disable kvmclock from machine_shutdown() hook and this only happens for boot CPU. We need to disable it for all CPUs to guard against memory corruption e.g. on restore from hibernate. Note, writing '0' to kvmclock MSR doesn't clear memory location, it just prevents hypervisor from updating the location so for the short while after write and while CPU is still alive, the clock remains usable and correct so we don't need to switch to some other clocksource.

Affected

Our own answer: ranges merged, affected separated from platform-only, with confidence and review flags.

v < 5.4.1252.6.26 ≤ v < 5.10.432.6.26 ≤ v < 5.12.102.6.26 ≤ v < 5.132.6.26 ≤ v < 5.4.1255.11 ≤ v < 5.12.105.5 ≤ v < 5.10.431e977aa12dd4f80688b1f243762212e75c6d7fe85.13 rc1
Vendor states this is fixed in 1df2dc09926f61319116c80ee85701df33577d70 (fixed)
Vendor states this is fixed in 3b0becf8b1ecf642a9edaf4c9628ffc641e490d6 (fixed)
Vendor states this is fixed in 9084fe1b3572664ad276f427dce575f580c9799a (fixed)
Vendor states this is fixed in c02027b5742b5aa804ef08a4a9db433295533046 (fixed)
Vendor states this is fixed in 2.6.26 (unaffected)
Vendor states this is fixed in 5.10.43 (unaffected)
Vendor states this is fixed in 5.12.10 (unaffected)
Vendor states this is fixed in 5.13 (unaffected)
Vendor states this is fixed in 5.4.125 (unaffected)

References (4)

Patch
Source: 416baaa9-dc9f-4396-8d5f-8c081fb06d67
https://git.kernel.org/stable/c/1df2dc09926f61319116c80ee85701df33577d70
Patch
Source: 416baaa9-dc9f-4396-8d5f-8c081fb06d67
https://git.kernel.org/stable/c/3b0becf8b1ecf642a9edaf4c9628ffc641e490d6
Patch
Source: 416baaa9-dc9f-4396-8d5f-8c081fb06d67
https://git.kernel.org/stable/c/9084fe1b3572664ad276f427dce575f580c9799a
Patch
Source: 416baaa9-dc9f-4396-8d5f-8c081fb06d67
https://git.kernel.org/stable/c/c02027b5742b5aa804ef08a4a9db433295533046

SSVC — Action Prioritization

SSVCNo known exploitNot automatablePartial impact

SSVC signals action urgency (what to patch first), separate from CVSS which measures severity.

CVSS

Attack Vector
LOCAL
Complexity
LOW
Privileges
LOW
User Interaction
NONE
Scope
UNCHANGED
Confidentiality
HIGH
Integrity
NONE
Availability
HIGH
Vector?

Quick Info

StatusANALYZED
CWE
CWE-459

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