Vulnerability-Lookup

FKIE_CVE-2022-50227

Vulnerability from fkie_nvd - Published: 2025-06-18 11:15 - Updated: 2026-08-04 10:18

Severity

7.8 (High) - CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H
5.5 (Medium) - CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:H

Summary

In the Linux kernel, the following vulnerability has been resolved: KVM: x86/xen: Initialize Xen timer only once Add a check for existing xen timers before initializing a new one. Currently kvm_xen_init_timer() is called on every KVM_XEN_VCPU_ATTR_TYPE_TIMER, which is causing the following ODEBUG crash when vcpu->arch.xen.timer is already set. ODEBUG: init active (active state 0) object type: hrtimer hint: xen_timer_callbac0 RIP: 0010:debug_print_object+0x16e/0x250 lib/debugobjects.c:502 Call Trace: __debug_object_init debug_hrtimer_init debug_init hrtimer_init kvm_xen_init_timer kvm_xen_vcpu_set_attr kvm_arch_vcpu_ioctl kvm_vcpu_ioctl vfs_ioctl

References

	URL	Tags
	416baaa9-dc9f-4396-8d5f-8c081fb06d67	https://git.kernel.org/stable/c/9a9b5771e930f408c3419799000f76a9abaf2278	Patch
	416baaa9-dc9f-4396-8d5f-8c081fb06d67	https://git.kernel.org/stable/c/af735db31285fa699384c649be72a9f32ecbb665	Patch

Impacted products

	Vendor	Product	Version
	linux	linux_kernel	*

JSON

To clipboard

{
  "affected": [
    {
      "affectedData": [
        {
          "defaultStatus": "unaffected",
          "product": "Linux",
          "programFiles": [
            "arch/x86/kvm/xen.c"
          ],
          "repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git",
          "vendor": "Linux",
          "versions": [
            {
              "lessThan": "9a9b5771e930f408c3419799000f76a9abaf2278",
              "status": "affected",
              "version": "536395260582be7443b0b35b0bbb89ffe3947f62",
              "versionType": "git"
            },
            {
              "lessThan": "af735db31285fa699384c649be72a9f32ecbb665",
              "status": "affected",
              "version": "536395260582be7443b0b35b0bbb89ffe3947f62",
              "versionType": "git"
            }
          ]
        },
        {
          "defaultStatus": "affected",
          "product": "Linux",
          "programFiles": [
            "arch/x86/kvm/xen.c"
          ],
          "repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git",
          "vendor": "Linux",
          "versions": [
            {
              "status": "affected",
              "version": "5.19"
            },
            {
              "lessThan": "5.19",
              "status": "unaffected",
              "version": "0",
              "versionType": "semver"
            },
            {
              "lessThanOrEqual": "5.19.*",
              "status": "unaffected",
              "version": "5.19.2",
              "versionType": "semver"
            },
            {
              "lessThanOrEqual": "*",
              "status": "unaffected",
              "version": "6.0",
              "versionType": "original_commit_for_fix"
            }
          ]
        }
      ],
      "source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67"
    }
  ],
  "configurations": [
    {
      "nodes": [
        {
          "cpeMatch": [
            {
              "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*",
              "matchCriteriaId": "A1A2A5A5-4598-4D7E-BA07-4660398D6C8F",
              "versionEndExcluding": "5.19.2",
              "versionStartIncluding": "5.19",
              "vulnerable": true
            }
          ],
          "negate": false,
          "operator": "OR"
        }
      ]
    }
  ],
  "cveTags": [],
  "descriptions": [
    {
      "lang": "en",
      "value": "In the Linux kernel, the following vulnerability has been resolved:\n\nKVM: x86/xen: Initialize Xen timer only once\n\nAdd a check for existing xen timers before initializing a new one.\n\nCurrently kvm_xen_init_timer() is called on every\nKVM_XEN_VCPU_ATTR_TYPE_TIMER, which is causing the following ODEBUG\ncrash when vcpu-\u003earch.xen.timer is already set.\n\nODEBUG: init active (active state 0)\nobject type: hrtimer hint: xen_timer_callbac0\nRIP: 0010:debug_print_object+0x16e/0x250 lib/debugobjects.c:502\nCall Trace:\n__debug_object_init\ndebug_hrtimer_init\ndebug_init\nhrtimer_init\nkvm_xen_init_timer\nkvm_xen_vcpu_set_attr\nkvm_arch_vcpu_ioctl\nkvm_vcpu_ioctl\nvfs_ioctl"
    },
    {
      "lang": "es",
      "value": "En el kernel de Linux, se ha resuelto la siguiente vulnerabilidad: KVM: x86/xen: Inicializar el temporizador Xen solo una vez. Se ha a\u00f1adido una comprobaci\u00f3n de los temporizadores Xen existentes antes de inicializar uno nuevo. Actualmente, se llama a kvm_xen_init_timer() en cada KVM_XEN_VCPU_ATTR_TYPE_TIMER, lo que provoca el siguiente fallo de ODEBUG cuando vcpu-\u0026gt;arch.xen.timer ya est\u00e1 configurado. ODEBUG: init activo (estado activo 0) tipo de objeto: hrtimer sugerencia: xen_timer_callbac0 RIP: 0010:debug_print_object+0x16e/0x250 lib/debugobjects.c:502 Seguimiento de llamadas: __debug_object_init debug_hrtimer_init debug_init hrtimer_init kvm_xen_init_timer kvm_xen_vcpu_set_attr kvm_arch_vcpu_ioctl kvm_vcpu_ioctl vfs_ioctl"
    }
  ],
  "id": "CVE-2022-50227",
  "lastModified": "2026-08-04T10:18:07.817",
  "metrics": {
    "cvssMetricV31": [
      {
        "cvssData": {
          "attackComplexity": "LOW",
          "attackVector": "LOCAL",
          "availabilityImpact": "HIGH",
          "baseScore": 7.8,
          "baseSeverity": "HIGH",
          "confidentialityImpact": "HIGH",
          "integrityImpact": "HIGH",
          "privilegesRequired": "LOW",
          "scope": "UNCHANGED",
          "userInteraction": "NONE",
          "vectorString": "CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H",
          "version": "3.1"
        },
        "exploitabilityScore": 1.8,
        "impactScore": 5.9,
        "source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
        "type": "Secondary"
      },
      {
        "cvssData": {
          "attackComplexity": "LOW",
          "attackVector": "LOCAL",
          "availabilityImpact": "HIGH",
          "baseScore": 5.5,
          "baseSeverity": "MEDIUM",
          "confidentialityImpact": "NONE",
          "integrityImpact": "NONE",
          "privilegesRequired": "LOW",
          "scope": "UNCHANGED",
          "userInteraction": "NONE",
          "vectorString": "CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:H",
          "version": "3.1"
        },
        "exploitabilityScore": 1.8,
        "impactScore": 3.6,
        "source": "nvd@nist.gov",
        "type": "Primary"
      }
    ]
  },
  "published": "2025-06-18T11:15:53.743",
  "references": [
    {
      "source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
      "tags": [
        "Patch"
      ],
      "url": "https://git.kernel.org/stable/c/9a9b5771e930f408c3419799000f76a9abaf2278"
    },
    {
      "source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
      "tags": [
        "Patch"
      ],
      "url": "https://git.kernel.org/stable/c/af735db31285fa699384c649be72a9f32ecbb665"
    }
  ],
  "sourceIdentifier": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
  "vulnStatus": "Modified",
  "weaknesses": [
    {
      "description": [
        {
          "lang": "en",
          "value": "NVD-CWE-noinfo"
        }
      ],
      "source": "nvd@nist.gov",
      "type": "Primary"
    }
  ]
}

CVE-2022-50227 (GCVE-0-2022-50227)

Vulnerability from cvelistv5 – Published: 2025-06-18 11:03 – Updated: 2026-08-05 08:57

Title

KVM: x86/xen: Initialize Xen timer only once

Summary

Severity

7.8 (High)


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

Assigner

Linux mitre root

References

2 references

URL	Tags
https://git.kernel.org/stable/c/9a9b5771e930f408c…
https://git.kernel.org/stable/c/af735db31285fa699…

Impacted products

2 products

Vendor	Product	Version
Linux	Linux	Affected: 536395260582be7443b0b35b0bbb89ffe3947f62 , < 9a9b5771e930f408c3419799000f76a9abaf2278 (git) Affected: 536395260582be7443b0b35b0bbb89ffe3947f62 , < af735db31285fa699384c649be72a9f32ecbb665 (git)
Linux	Linux	Affected: 5.19 Unaffected: 0 , < 5.19 (semver) Unaffected: 5.19.2 , ≤ 5.19.* (semver) Unaffected: 6.0 , ≤ * (original_commit_for_fix)

Show details on NVD website

JSON

To clipboard

{
  "containers": {
    "cna": {
      "affected": [
        {
          "defaultStatus": "unaffected",
          "product": "Linux",
          "programFiles": [
            "arch/x86/kvm/xen.c"
          ],
          "repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git",
          "vendor": "Linux",
          "versions": [
            {
              "lessThan": "9a9b5771e930f408c3419799000f76a9abaf2278",
              "status": "affected",
              "version": "536395260582be7443b0b35b0bbb89ffe3947f62",
              "versionType": "git"
            },
            {
              "lessThan": "af735db31285fa699384c649be72a9f32ecbb665",
              "status": "affected",
              "version": "536395260582be7443b0b35b0bbb89ffe3947f62",
              "versionType": "git"
            }
          ]
        },
        {
          "defaultStatus": "affected",
          "product": "Linux",
          "programFiles": [
            "arch/x86/kvm/xen.c"
          ],
          "repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git",
          "vendor": "Linux",
          "versions": [
            {
              "status": "affected",
              "version": "5.19"
            },
            {
              "lessThan": "5.19",
              "status": "unaffected",
              "version": "0",
              "versionType": "semver"
            },
            {
              "lessThanOrEqual": "5.19.*",
              "status": "unaffected",
              "version": "5.19.2",
              "versionType": "semver"
            },
            {
              "lessThanOrEqual": "*",
              "status": "unaffected",
              "version": "6.0",
              "versionType": "original_commit_for_fix"
            }
          ]
        }
      ],
      "cpeApplicability": [
        {
          "nodes": [
            {
              "cpeMatch": [
                {
                  "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*",
                  "versionEndExcluding": "5.19.2",
                  "versionStartIncluding": "5.19",
                  "vulnerable": true
                },
                {
                  "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*",
                  "versionEndExcluding": "6.0",
                  "versionStartIncluding": "5.19",
                  "vulnerable": true
                }
              ],
              "negate": false,
              "operator": "OR"
            }
          ]
        }
      ],
      "descriptions": [
        {
          "lang": "en",
          "value": "In the Linux kernel, the following vulnerability has been resolved:\n\nKVM: x86/xen: Initialize Xen timer only once\n\nAdd a check for existing xen timers before initializing a new one.\n\nCurrently kvm_xen_init_timer() is called on every\nKVM_XEN_VCPU_ATTR_TYPE_TIMER, which is causing the following ODEBUG\ncrash when vcpu-\u003earch.xen.timer is already set.\n\nODEBUG: init active (active state 0)\nobject type: hrtimer hint: xen_timer_callbac0\nRIP: 0010:debug_print_object+0x16e/0x250 lib/debugobjects.c:502\nCall Trace:\n__debug_object_init\ndebug_hrtimer_init\ndebug_init\nhrtimer_init\nkvm_xen_init_timer\nkvm_xen_vcpu_set_attr\nkvm_arch_vcpu_ioctl\nkvm_vcpu_ioctl\nvfs_ioctl"
        }
      ],
      "metrics": [
        {
          "cvssV3_1": {
            "baseScore": 7.8,
            "baseSeverity": "HIGH",
            "vectorString": "CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H",
            "version": "3.1"
          },
          "scenarios": [
            {
              "lang": "en",
              "value": "AV:L - Triggered only via the host KVM_XEN_VCPU_SET_ATTR vCPU ioctl on /dev/kvm; guest Xen timer hypercalls call kvm_xen_start_timer but never kvm_xen_init_timer, so this is not remotely reachable.\nAC:L - An attacker with a vCPU fd can reliably reproduce by issuing KVM_XEN_VCPU_ATTR_TYPE_TIMER twice with a non-zero port and expires_ns, fully controlling both the initial arming and the re-init; no race or external condition is required.\nPR:L - Reachable by any unprivileged local user who can open /dev/kvm (typically kvm-group membership), create a VM/vCPU, and issue the ioctl; no CAP_SYS_ADMIN or init-namespace root is required.\nUI:N - Exploitation is entirely attacker-driven through ioctl calls; no victim action is needed.\nS:U - This is host userspace (VMM) corrupting the host kernel timer subsystem, not a guest-to-host escape; impact stays within the host kernel authority.\nC:H - Without DEBUG_OBJECTS, hrtimer_init memset()s an still-enqueued hrtimer, corrupting the timerqueue rbtree and enabling use-after-free primitives that can yield arbitrary kernel reads.\nI:H - The same timer-queue corruption provides a write/UAF primitive against kernel timer structures, which can be leveraged for control-flow hijacking or arbitrary writes.\nA:H - Re-init of an active hrtimer causes kernel WARN/oops under debugobjects and timer-subsystem crashes or hangs on production kernels when the corrupted rbtree is walked."
            }
          ]
        }
      ],
      "providerMetadata": {
        "dateUpdated": "2026-08-05T08:57:47.222Z",
        "orgId": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
        "shortName": "Linux"
      },
      "references": [
        {
          "url": "https://git.kernel.org/stable/c/9a9b5771e930f408c3419799000f76a9abaf2278"
        },
        {
          "url": "https://git.kernel.org/stable/c/af735db31285fa699384c649be72a9f32ecbb665"
        }
      ],
      "title": "KVM: x86/xen: Initialize Xen timer only once",
      "x_generator": {
        "engine": "bippy-1.2.0"
      }
    }
  },
  "cveMetadata": {
    "assignerOrgId": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
    "assignerShortName": "Linux",
    "cveId": "CVE-2022-50227",
    "datePublished": "2025-06-18T11:03:59.885Z",
    "dateReserved": "2025-06-18T10:57:27.432Z",
    "dateUpdated": "2026-08-05T08:57:47.222Z",
    "state": "PUBLISHED"
  },
  "dataType": "CVE_RECORD",
  "dataVersion": "5.2"
}

Sightings

Author	Source	Type	Date	Other

Nomenclature

Seen: The vulnerability was mentioned, discussed, or observed by the user.
Confirmed: The vulnerability has been validated from an analyst's perspective.
Published Proof of Concept: A public proof of concept is available for this vulnerability.
Exploited: The vulnerability was observed as exploited by the user who reported the sighting.
Patched: The vulnerability was observed as successfully patched by the user who reported the sighting.
Not exploited: The vulnerability was not observed as exploited by the user who reported the sighting.
Not confirmed: The user expressed doubt about the validity of the vulnerability.
Not patched: The vulnerability was not observed as successfully patched by the user who reported the sighting.

Detection rules are retrieved from Rulezet.

The MITRE ATT&CK techniques below are AI-generated suggestions, inferred from the description of the vulnerability by the CIRCL/vulnerability-attack-technique-classification-roberta-base model, served locally by ML-Gateway. They have not been verified by an analyst and are provided for guidance only.
The approach is described in our paper Mapping CVEs to MITRE ATT&CK Techniques: A Curated Gold-Set Classifier and the Limits of LLM-Assisted Label Expansion.
Browse all ATT&CK techniques and the vulnerabilities related to each.

Related by attack behaviour

Vulnerabilities whose description is nearest to this one in the vector space of the CIRCL/vulnerability-attack-technique-biencoder model. This is a similarity search over the bi-encoder space (plain cosine), not a classification, and it has no measured accuracy.