Description
In the Linux kernel, the following vulnerability has been resolved:

KVM: nVM: Ensure INVVPID is emulated on the correct physical CPU

When emulating INVVPID, KVM executes INVVPID on the physical CPU using
vpid02 (instead of the L1 assigned VPID), after doing some validations
on the operands. However, it is possible that the physical CPU KVM
executes INVVPID on is different from the CPU L2 is running on.

For example, in the following scenario:
- L2 runs on CPU #1 and exits to L1 (vmx->nested.vmcs02.cpu=1)
- L1 migrates to CPU #2 and executes INVVPID
- KVM executes INVVPID on CPU #2
- L1 migrates back to CPU #1 and runs L2 (vmx->nested.vmcs02.cpu=1)

The TLB entries on CPU #1 are never invalidated, because INVVPID was
executed on CPU #2, and vmcs02 never ran on a different pCPU (i.e.
vmx_vcpu_load_vmcs() will *not* request KVM_REQ_TLB_FLUSH).

Ensure that INVVPID is being executed on the same pCPU that L2 last ran
on, and if not, fallback to clearing last_vpid=0 to trigger a full VPID
flush on the next nested VM-Enter (as KVM will detect L1 using a
different VPID for L2). If L2 ends up running on a different pCPU, KVM
will flush the TLB anyway through vmx_vcpu_load_vmcs().
Published: 2026-09-16
Score: n/a
EPSS: n/a
KEV: No
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Remediation

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History

Wed, 16 Sep 2026 10:45:00 +0000

Type Values Removed Values Added
Description In the Linux kernel, the following vulnerability has been resolved: KVM: nVM: Ensure INVVPID is emulated on the correct physical CPU When emulating INVVPID, KVM executes INVVPID on the physical CPU using vpid02 (instead of the L1 assigned VPID), after doing some validations on the operands. However, it is possible that the physical CPU KVM executes INVVPID on is different from the CPU L2 is running on. For example, in the following scenario: - L2 runs on CPU #1 and exits to L1 (vmx->nested.vmcs02.cpu=1) - L1 migrates to CPU #2 and executes INVVPID - KVM executes INVVPID on CPU #2 - L1 migrates back to CPU #1 and runs L2 (vmx->nested.vmcs02.cpu=1) The TLB entries on CPU #1 are never invalidated, because INVVPID was executed on CPU #2, and vmcs02 never ran on a different pCPU (i.e. vmx_vcpu_load_vmcs() will *not* request KVM_REQ_TLB_FLUSH). Ensure that INVVPID is being executed on the same pCPU that L2 last ran on, and if not, fallback to clearing last_vpid=0 to trigger a full VPID flush on the next nested VM-Enter (as KVM will detect L1 using a different VPID for L2). If L2 ends up running on a different pCPU, KVM will flush the TLB anyway through vmx_vcpu_load_vmcs().
Title KVM: nVM: Ensure INVVPID is emulated on the correct physical CPU
First Time appeared Linux
Linux linux Kernel
CPEs cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*
Vendors & Products Linux
Linux linux Kernel
References

Subscriptions

Linux Linux Kernel
cve-icon MITRE

Status: PUBLISHED

Assigner: Linux

Published:

Updated: 2026-09-16T10:32:20.855Z

Reserved: 2026-09-11T19:38:34.775Z

Link: CVE-2026-89929

cve-icon Vulnrichment

No data.

cve-icon NVD

Status : Received

Published: 2026-09-16T11:17:02.180

Modified: 2026-09-16T11:17:02.180

Link: CVE-2026-89929

cve-icon Redhat

No data.

cve-icon OpenCVE Enrichment

No data.

Weaknesses

No weakness.