CVE-2021-47110

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.

CVSS v3 7.1 HIGH

7.1^/10

CVSS v3 : HIGH

V3 Legend

Vector :

Exploitability : 1.8 / Impact : 5.2

Attack Vector LOCAL

Attack Complexity LOW

Privileges Required LOW

User Interaction NONE

Confidentiality Impact HIGH

Integrity Impact NONE

Availability Impact HIGH

Scope UNCHANGED

References

Link	Resource
https://git.kernel.org/stable/c/1df2dc09926f61319116c80ee85701df33577d70	Patch
https://git.kernel.org/stable/c/3b0becf8b1ecf642a9edaf4c9628ffc641e490d6	Patch
https://git.kernel.org/stable/c/9084fe1b3572664ad276f427dce575f580c9799a	Patch
https://git.kernel.org/stable/c/c02027b5742b5aa804ef08a4a9db433295533046	Patch
https://git.kernel.org/stable/c/1df2dc09926f61319116c80ee85701df33577d70	Patch
https://git.kernel.org/stable/c/3b0becf8b1ecf642a9edaf4c9628ffc641e490d6	Patch
https://git.kernel.org/stable/c/9084fe1b3572664ad276f427dce575f580c9799a	Patch
https://git.kernel.org/stable/c/c02027b5742b5aa804ef08a4a9db433295533046	Patch

Configurations

Configuration 1 (hide)

OR	cpe:2.3:o:linux:linux_kernel::::::::
	cpe:2.3:o:linux:linux_kernel::::::::
	cpe:2.3:o:linux:linux_kernel::::::::
	cpe:2.3:o:linux:linux_kernel:5.13:rc1::::::

History

13 Mar 2025, 19:36

Type	Values Removed	Values Added
CWE		CWE-459
CVSS	v2 : ~~unknown~~ v3 : ~~unknown~~	v2 : unknown v3 : 7.1
CPE		cpe:2.3:o:linux:linux_kernel:5.13:rc1:::::: cpe:2.3:o:linux:linux_kernel::::::::
References	~~() https://git.kernel.org/stable/c/1df2dc09926f61319116c80ee85701df33577d70 -~~	() https://git.kernel.org/stable/c/1df2dc09926f61319116c80ee85701df33577d70 - Patch
References	~~() https://git.kernel.org/stable/c/3b0becf8b1ecf642a9edaf4c9628ffc641e490d6 -~~	() https://git.kernel.org/stable/c/3b0becf8b1ecf642a9edaf4c9628ffc641e490d6 - Patch
References	~~() https://git.kernel.org/stable/c/9084fe1b3572664ad276f427dce575f580c9799a -~~	() https://git.kernel.org/stable/c/9084fe1b3572664ad276f427dce575f580c9799a - Patch
References	~~() https://git.kernel.org/stable/c/c02027b5742b5aa804ef08a4a9db433295533046 -~~	() https://git.kernel.org/stable/c/c02027b5742b5aa804ef08a4a9db433295533046 - Patch
First Time		Linux linux Kernel Linux

21 Nov 2024, 06:35

Type	Values Removed	Values Added
References	~~() https://git.kernel.org/stable/c/1df2dc09926f61319116c80ee85701df33577d70 -~~	() https://git.kernel.org/stable/c/1df2dc09926f61319116c80ee85701df33577d70 -
References	~~() https://git.kernel.org/stable/c/3b0becf8b1ecf642a9edaf4c9628ffc641e490d6 -~~	() https://git.kernel.org/stable/c/3b0becf8b1ecf642a9edaf4c9628ffc641e490d6 -
References	~~() https://git.kernel.org/stable/c/9084fe1b3572664ad276f427dce575f580c9799a -~~	() https://git.kernel.org/stable/c/9084fe1b3572664ad276f427dce575f580c9799a -
References	~~() https://git.kernel.org/stable/c/c02027b5742b5aa804ef08a4a9db433295533046 -~~	() https://git.kernel.org/stable/c/c02027b5742b5aa804ef08a4a9db433295533046 -
Summary		(es) En el kernel de Linux, se resolvió la siguiente vulnerabilidad: x86/kvm: deshabilite kvmclock en todas las CPU al apagar Actualmente, deshabilitamos kvmclock desde el enlace machine_shutdown() y esto solo sucede para la CPU de arranque. Necesitamos deshabilitarlo para todas las CPU para protegernos contra la corrupción de la memoria, por ejemplo, al restaurar desde la hibernación. Tenga en cuenta que escribir '0' en kvmclock MSR no borra la ubicación de la memoria, solo evita que el hipervisor actualice la ubicación, por lo que durante un breve período después de la escritura y mientras la CPU aún está activa, el reloj permanece utilizable y correcto, por lo que no lo necesitamos. para cambiar a alguna otra fuente de reloj.

15 Mar 2024, 21:15

Type	Values Removed	Values Added
New CVE

Information

Published : 2024-03-15 21:15

Updated : 2025-03-13 19:36

NVD link : CVE-2021-47110

Mitre link : CVE-2021-47110

CVE.ORG link : CVE-2021-47110

JSON object : View

Products Affected

linux

linux_kernel

CWE

CWE-459

Incomplete Cleanup

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7.1 /10