LiveActive security incident?Get immediate response
CVE Record

CVE-2022-48764: KVM: x86: Free kvm_cpuid_entry2 array on post-KVM_RUN KVM_SET_CPUID{,2}

In the Linux kernel, the following vulnerability has been resolved: KVM: x86: Free kvm_cpuid_entry2 array on post-KVM_RUN KVM_SET_CPUID{,2} Free the "struct kvm_cpuid_entry2" array on successful post-KVM_RUN KVM_SET_CPUID{,2} to fix a memory leak, the callers of kvm_set_cpuid() free the array only on failure. BUG: memory leak unreferenced object 0xffff88810963a800 (size 2048): comm "syz-executor025", pid 3610, jiffies 4294944928 (age 8.080s) hex dump (first 32 bytes): 00 00 00 00 00 00 00 00 00 00 00 00 0d 00 00 00 ................ 47 65 6e 75 6e 74 65 6c 69 6e 65 49 00 00 00 00 GenuntelineI.... backtrace: [<ffffffff814948ee>] kmalloc_node include/linux/slab.h:604 [inline] [<ffffffff814948ee>] kvmalloc_node+0x3e/0x100 mm/util.c:580 [<ffffffff814950f2>] kvmalloc include/linux/slab.h:732 [inline] [<ffffffff814950f2>] vmemdup_user+0x22/0x100 mm/util.c:199 [<ffffffff8109f5ff>] kvm_vcpu_ioctl_set_cpuid2+0x8f/0xf0 arch/x86/kvm/cpuid.c:423 [<ffffffff810711b9>] kvm_arch_vcpu_ioctl+0xb99/0x1e60 arch/x86/kvm/x86.c:5251 [<ffffffff8103e92d>] kvm_vcpu_ioctl+0x4ad/0x950 arch/x86/kvm/../../../virt/kvm/kvm_main.c:4066 [<ffffffff815afacc>] vfs_ioctl fs/ioctl.c:51 [inline] [<ffffffff815afacc>] __do_sys_ioctl fs/ioctl.c:874 [inline] [<ffffffff815afacc>] __se_sys_ioctl fs/ioctl.c:860 [inline] [<ffffffff815afacc>] __x64_sys_ioctl+0xfc/0x140 fs/ioctl.c:860 [<ffffffff844a3335>] do_syscall_x64 arch/x86/entry/common.c:50 [inline] [<ffffffff844a3335>] do_syscall_64+0x35/0xb0 arch/x86/entry/common.c:80 [<ffffffff84600068>] entry_SYSCALL_64_after_hwframe+0x44/0xae

MediumCVSS 5.3Not KEV-listedUpdated
Discuss exposureBack to CVEs
Glexia's TakeAutomated analysismoderate

Security readout for executives and security teams

Plain-English summary

This is a Linux kernel KVM memory-leak flaw in x86 virtualization handling. A local user with permission to interact with KVM could cause kernel memory to be leaked when changing virtual CPU CPUID settings after a VM has run. Business impact is mainly stability and resource exhaustion risk on virtualization hosts, not remote compromise.

Executive priority

Treat as a moderate-priority virtualization host issue. It is not evidenced as remotely exploitable or actively exploited, but it can affect host stability where KVM access is shared. Patch during the next kernel maintenance window, faster for multi-tenant or untrusted workload environments.

Technical view

The flaw is in KVM x86 handling of KVM_SET_CPUID/KVM_SET_CPUID2 after KVM_RUN. On success, callers did not free a kvm_cpuid_entry2 array, producing an unreferenced kernel allocation. The CVSS vector is local, low complexity, low privileges, no user interaction, unchanged scope, with low confidentiality, integrity, and availability impact.

Likely exposure

Exposure is most relevant to x86 Linux systems running KVM where untrusted or less-trusted local users can access KVM VM controls. The source bundle does not provide complete distribution package ranges, so affected fleet scope requires vendor kernel mapping.

Exploitation context

The provided sources do not show active exploitation, and KEV is false. Exploitation requires local privileges and KVM access, which generally limits exposure to virtualization hosts, CI runners, developer systems, or multi-tenant environments that permit KVM use.

Researcher notes

Evidence points to a successful-path memory leak after post-run CPUID updates in KVM x86. The bundle includes stable kernel commit references but limited affected-version detail. Avoid assuming distro impact without mapping downstream kernel packages to those commits.

Mitigation direction

  • Apply a Linux kernel update that includes the referenced stable fixes.
  • Check distribution vendor advisories for exact affected and fixed package versions.
  • Restrict KVM access to trusted users and service accounts.
  • Prioritize shared virtualization hosts and systems with untrusted local workloads.

Validation and detection

  • Inventory x86 Linux systems with KVM enabled or /dev/kvm exposed.
  • Map running kernel builds to vendor advisories or the referenced fix commits.
  • Review which users or services can access KVM device permissions.
  • Confirm patched systems after update through normal kernel version management.
Prepared
Confidence
medium
Sources
4

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

These mappings and lookup hints may be relevant to the vulnerability behavior, CWE, affected product, or exposure path. Glexia-inferred context is not an official MITRE, ATT&CK, CWE, or CVE Program mapping.

ATT&CK lookup starting points

Use these exact CWE pages and searches to review the Glexia ATT&CK library from this CVE's weakness and description context.

cve · low confidence lookup

CVE-2022-48764 mapping review

Open the CVE-to-ATT&CK bridge for reviewed, inferred, or future official mappings tied to this CVE.

Open ATT&CK lookup
Vulnerability profileCVE Program record
Severity
Medium
CVSS
5.3 (3.1)
Known Exploited
No
Published

Vector: CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:L/I:L/A:L

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.

1CVSS vectors
3Timeline events
2ADP providers
3Source links

SSVC decision data

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

CVSS vector scores

1 official score

We collect every scored CVSS vector available in the official CNA and ADP containers. When more than one version is present, the table keeps the source vectors side by side instead of collapsing them into the highest score.

ScoreVersionSeverityVectorExploitImpactSource
5.3CVSS 3.1MediumCVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:L/I:L/A:L1.83.4CISA-ADP

Vulnerability scoring details

Base CVSS 3.1 score

5.3Medium
CVSS 3.1 vector shape for CVE-2022-48764Attack VectorAttack ComplexityPrivileges RequiredUser InteractionScopeConfidentiality ImpactIntegrity ImpactAvailability Impact

Vector: CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:L/I:L/A:L

Attack Vector
NetworkAdjacentLocalPhysical
Attack Complexity
LowHigh
Privileges Required
NoneLowHigh
User Interaction
NoneRequired
Scope
ChangedUnchanged
Confidentiality Impact
HighLowNone
Integrity Impact
HighLowNone
Availability Impact
HighLowNone

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

CISA-ADPCISA ADP Vulnrichment
cvssV3_1other:ssvc
CVECVE Program Container

Source materials

Affected products

Products and packages named in the record

VendorProductVersion / packageStatus
LinuxLinux24e7590c60aa9487b8e43583dc9885f62f8216c1, c6617c61e8fe44b9e9fdfede921f61cac6b5149dunaffected
LinuxLinux5.16.3unaffected
Weakness

CWE details

No CWE listed

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