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CVE Record

CVE-2022-48765: KVM: LAPIC: Also cancel preemption timer during SET_LAPIC

In the Linux kernel, the following vulnerability has been resolved: KVM: LAPIC: Also cancel preemption timer during SET_LAPIC The below warning is splatting during guest reboot. ------------[ cut here ]------------ WARNING: CPU: 0 PID: 1931 at arch/x86/kvm/x86.c:10322 kvm_arch_vcpu_ioctl_run+0x874/0x880 [kvm] CPU: 0 PID: 1931 Comm: qemu-system-x86 Tainted: G I 5.17.0-rc1+ #5 RIP: 0010:kvm_arch_vcpu_ioctl_run+0x874/0x880 [kvm] Call Trace: <TASK> kvm_vcpu_ioctl+0x279/0x710 [kvm] __x64_sys_ioctl+0x83/0xb0 do_syscall_64+0x3b/0xc0 entry_SYSCALL_64_after_hwframe+0x44/0xae RIP: 0033:0x7fd39797350b This can be triggered by not exposing tsc-deadline mode and doing a reboot in the guest. The lapic_shutdown() function which is called in sys_reboot path will not disarm the flying timer, it just masks LVTT. lapic_shutdown() clears APIC state w/ LVT_MASKED and timer-mode bit is 0, this can trigger timer-mode switch between tsc-deadline and oneshot/periodic, which can result in preemption timer be cancelled in apic_update_lvtt(). However, We can't depend on this when not exposing tsc-deadline mode and oneshot/periodic modes emulated by preemption timer. Qemu will synchronise states around reset, let's cancel preemption timer under KVM_SET_LAPIC.

UnknownCVSS not scoredNot KEV-listedUpdated
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Glexia's TakeAutomated analysisunknown

Security readout for executives and security teams

Plain-English summary

This Linux kernel KVM issue affects virtualization hosts. A guest reboot can leave a KVM local APIC preemption timer active when LAPIC state is reset, producing a kernel warning. The provided sources describe a kernel fix, but do not give CVSS, business impact, or evidence of compromise.

Executive priority

Treat as a virtualization platform maintenance item until vendor severity is clearer. Prioritize patching shared KVM hosts, but the provided evidence does not support emergency response or active-attack assumptions.

Technical view

KVM LAPIC handling did not always cancel the preemption timer during KVM_SET_LAPIC. When TSC-deadline mode is not exposed and a guest reboots, lapic_shutdown() may mask LVTT without disarming the active timer, leaving inconsistent timer state around QEMU reset synchronization.

Likely exposure

Exposure is most relevant to Linux systems acting as KVM/QEMU hypervisors. The bundle lists Linux kernel versions including 4.10, 5.15.19, 5.16.5, and 5.17, but version-range semantics are incomplete.

Exploitation context

The source describes triggering during guest reboot under specific KVM LAPIC timer conditions. There is no KEV listing, no cited active exploitation, and no exploit maturity evidence in the bundle.

Researcher notes

The bundle supports a narrow KVM LAPIC timer-state bug and fix references. It does not establish privilege impact, denial-of-service severity, affected distribution packages, or exploitability beyond a guest reboot trigger condition.

Mitigation direction

  • Apply Linux kernel updates that include the referenced stable KVM fixes.
  • For distribution kernels, follow the Linux vendor or distribution advisory for backported fixes.
  • Prioritize affected KVM/QEMU virtualization hosts over non-hypervisor Linux systems.
  • Avoid direct deployment shortcuts; use normal tested kernel rollout procedures.

Validation and detection

  • Inventory Linux hosts running KVM or QEMU virtualization workloads.
  • Check whether deployed kernels include the referenced stable commits or vendor backports.
  • Review kernel logs for KVM warnings during guest reboot cycles.
  • Confirm patched hosts can reboot guests without recurring LAPIC timer warnings.
Prepared
Confidence
medium
Sources
5

Public sources used

Generated from the cited source records. This long-tail analysis has not been individually reviewed by a named human.

Potential ATT&CK relevance

Conservative CVE-to-ATT&CK context

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CVE-2022-48765 mapping review

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Vulnerability profileCVE Program record
Severity
Unknown
CVSS
Not scored
Known Exploited
No
Published
Official CVE source material

CNA and ADP enrichment extracted from CVE v5

These fields come from the CVE record and ADP containers, not from Glexia's Take. They preserve time-varying source decisions such as CISA SSVC, KEV status, CVSS metrics, and provider references.

0CVSS vectors
3Timeline events
2ADP providers
4Source links

SSVC decision data

CISA-ADPCISA Coordinator
Timestamp
Version
2.0.3
Exploitation: noneAutomatable: noTechnical Impact: partial

Vulnerability timeline

Timeline events are normalized from CVE metadata, CNA source timelines, ADP timelines, and KEV metadata when present.

  1. CVE reservedCVE Program

    The CVE ID was reserved by the assigning CNA.

  2. CVE publishedCVE Program

    The CVE record was published.

  3. CVE updatedCVE Program

    The CVE record metadata indicates this as the latest update time.

ADP provider summaries

CVECVE Program Container
CISA-ADPCISA ADP Vulnrichment
other:ssvc

Source materials

Affected products

Products and packages named in the record

VendorProductVersion / packageStatus
LinuxLinux8003c9ae204e21204e49816c5ea629357e283b06, 8003c9ae204e21204e49816c5ea629357e283b06, 8003c9ae204e21204e49816c5ea629357e283b06unaffected
LinuxLinux4.10, 0, 5.15.19, 5.16.5, 5.17affected
Weakness

CWE details

No CWE listed

CWE links open Glexia weakness intelligence pages with official CWE context, developer remediation guidance, and related CVE mappings.