Vulnerability-Lookup

CVE-2026-98927 (GCVE-0-2026-98927)

Vulnerability from cvelistv5 – Published: 2026-10-23 12:06 – Updated: 2026-10-24 14:09

Title

KVM: arm64: nv: Fix life cycle of the nested_mmus array

Summary

In the Linux kernel, the following vulnerability has been resolved: KVM: arm64: nv: Fix life cycle of the nested_mmus array The nested_mmus array holds the shadow page tables that are used when a guest is running a nested context. These structures are allocated on VCPU_INIT for whole guest, which implies that they may have to be relocated as the array grows. Should a VCPU_INIT occur whilst a vcpu is actively running an L2 and that the allocation requires relocation, that vcpu will still be running with a pointer to the previous structure, which will have been freed. Fix this by turning the array of structures to an array of pointers, which is now allocated at VM creation, sized to the absolute maximum that KVM can handle. In turn, each VCPU_INIT contributes S2_MMU_PER_VCPU to the pool. No reallocation is ever performed, and the life cycle of each object is much clearer: - the nested_mmus array is allocated in kvm_init_nested(), and freed in kvm_arch_destroy_vm() - s2_mmu structures are allocated in kvm_vcpu_init_nested(), and freed on kvm_arch_flush_shadow_all() Finally, the freeing of vcpu->arch.vncr_array is made consistent rather than being done on some failure paths, but not others.

Severity

7 (High)


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

Assigner

Linux CNA under the mitre root

CNA scorecard D 53/100 over 7056 records in the last 180 days details

References

4 references

URL	Tags
https://git.kernel.org/stable/c/ea242bdc29e8a8ff0…
https://git.kernel.org/stable/c/81e3f065a6485626f…
https://git.kernel.org/stable/c/512c93f4461b9a373…
https://git.kernel.org/stable/c/33346f8960c7bb6a3…

Impacted products

2 products

Vendor	Product	Version	CPE status
Linux	Linux	Affected: 4f128f8e1aaac189f83d0f828bcdb2986d8d2e51 , < ea242bdc29e8a8ff0e2447a64b3841114779f3af (git) Affected: 4f128f8e1aaac189f83d0f828bcdb2986d8d2e51 , < 81e3f065a6485626f816d791dfd5e00ddd12eff5 (git) Affected: 4f128f8e1aaac189f83d0f828bcdb2986d8d2e51 , < 512c93f4461b9a3735987f48423d438a9cd49e6a (git) Affected: 4f128f8e1aaac189f83d0f828bcdb2986d8d2e51 , < 33346f8960c7bb6a3b4e273b5cfe25c5a8be349f (git)	guessed
Linux	Linux	Affected: 6.11 Unaffected: 0 , < 6.11 (semver) Unaffected: 6.12.113 , ≤ 6.12.* (semver) Unaffected: 6.18.56 , ≤ 6.18.* (semver) Unaffected: 7.2.9 , ≤ 7.2.* (semver) Unaffected: 7.3 , ≤ * (original_commit_for_fix)	guessed

Show details on NVD website

JSON

To clipboard

{
  "containers": {
    "cna": {
      "affected": [
        {
          "defaultStatus": "unaffected",
          "product": "Linux",
          "programFiles": [
            "arch/arm64/include/asm/kvm_host.h",
            "arch/arm64/include/asm/kvm_nested.h",
            "arch/arm64/kvm/arm.c",
            "arch/arm64/kvm/nested.c"
          ],
          "repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git",
          "vendor": "Linux",
          "versions": [
            {
              "lessThan": "ea242bdc29e8a8ff0e2447a64b3841114779f3af",
              "status": "affected",
              "version": "4f128f8e1aaac189f83d0f828bcdb2986d8d2e51",
              "versionType": "git"
            },
            {
              "lessThan": "81e3f065a6485626f816d791dfd5e00ddd12eff5",
              "status": "affected",
              "version": "4f128f8e1aaac189f83d0f828bcdb2986d8d2e51",
              "versionType": "git"
            },
            {
              "lessThan": "512c93f4461b9a3735987f48423d438a9cd49e6a",
              "status": "affected",
              "version": "4f128f8e1aaac189f83d0f828bcdb2986d8d2e51",
              "versionType": "git"
            },
            {
              "lessThan": "33346f8960c7bb6a3b4e273b5cfe25c5a8be349f",
              "status": "affected",
              "version": "4f128f8e1aaac189f83d0f828bcdb2986d8d2e51",
              "versionType": "git"
            }
          ]
        },
        {
          "defaultStatus": "affected",
          "product": "Linux",
          "programFiles": [
            "arch/arm64/include/asm/kvm_host.h",
            "arch/arm64/include/asm/kvm_nested.h",
            "arch/arm64/kvm/arm.c",
            "arch/arm64/kvm/nested.c"
          ],
          "repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git",
          "vendor": "Linux",
          "versions": [
            {
              "status": "affected",
              "version": "6.11"
            },
            {
              "lessThan": "6.11",
              "status": "unaffected",
              "version": "0",
              "versionType": "semver"
            },
            {
              "lessThanOrEqual": "6.12.*",
              "status": "unaffected",
              "version": "6.12.113",
              "versionType": "semver"
            },
            {
              "lessThanOrEqual": "6.18.*",
              "status": "unaffected",
              "version": "6.18.56",
              "versionType": "semver"
            },
            {
              "lessThanOrEqual": "7.2.*",
              "status": "unaffected",
              "version": "7.2.9",
              "versionType": "semver"
            },
            {
              "lessThanOrEqual": "*",
              "status": "unaffected",
              "version": "7.3",
              "versionType": "original_commit_for_fix"
            }
          ]
        }
      ],
      "cpeApplicability": [
        {
          "nodes": [
            {
              "cpeMatch": [
                {
                  "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*",
                  "versionEndExcluding": "6.12.113",
                  "versionStartIncluding": "6.11",
                  "vulnerable": true
                },
                {
                  "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*",
                  "versionEndExcluding": "6.18.56",
                  "versionStartIncluding": "6.11",
                  "vulnerable": true
                },
                {
                  "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*",
                  "versionEndExcluding": "7.2.9",
                  "versionStartIncluding": "6.11",
                  "vulnerable": true
                },
                {
                  "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*",
                  "versionEndExcluding": "7.3",
                  "versionStartIncluding": "6.11",
                  "vulnerable": true
                }
              ],
              "negate": false,
              "operator": "OR"
            }
          ]
        }
      ],
      "descriptions": [
        {
          "lang": "en",
          "value": "In the Linux kernel, the following vulnerability has been resolved:\n\nKVM: arm64: nv: Fix life cycle of the nested_mmus array\n\nThe nested_mmus array holds the shadow page tables that are used when\na guest is running a nested context. These structures are allocated on\nVCPU_INIT for whole guest, which implies that they may have to be\nrelocated as the array grows.\n\nShould a VCPU_INIT occur whilst a vcpu is actively running an L2 and\nthat the allocation requires relocation, that vcpu will still be\nrunning with a pointer to the previous structure, which will have been\nfreed.\n\nFix this by turning the array of structures to an array of pointers,\nwhich is now allocated at VM creation, sized to the absolute maximum\nthat KVM can handle.\n\nIn turn, each VCPU_INIT contributes S2_MMU_PER_VCPU to the pool. No\nreallocation is ever performed, and the life cycle of each object is\nmuch clearer:\n\n- the nested_mmus array is allocated in kvm_init_nested(), and freed\n  in kvm_arch_destroy_vm()\n\n- s2_mmu structures are allocated in kvm_vcpu_init_nested(), and freed\n  on kvm_arch_flush_shadow_all()\n\nFinally, the freeing of vcpu-\u003earch.vncr_array is made consistent\nrather than being done on some failure paths, but not others."
        }
      ],
      "metrics": [
        {
          "cvssV3_1": {
            "baseScore": 7,
            "baseSeverity": "HIGH",
            "vectorString": "CVSS:3.1/AV:L/AC:H/PR:L/UI:N/S:U/C:H/I:H/A:H",
            "version": "3.1"
          },
          "scenarios": [
            {
              "lang": "en",
              "value": "AV:L - A local process invokes KVM_ARM_VCPU_INIT on a vCPU fd; kvm_vcpu_ioctl() reaches patched kvm_vcpu_init_nested() through kvm_arch_vcpu_ioctl_vcpu_init() and kvm_setup_vcpu(). No network data path reaches this code.\nAC:H - The attacker can run one L2 vCPU while initializing another, but reachability requires FEAT_NV2 hardware booted in the explicitly non-default experimental kvm-arm.mode=nested mode. A low-privileged attacker cannot establish that host state.\nPR:L - kvm_vcpu_ioctl() requires the VM\u0027s owning mm but performs no capable() check. A basic local user granted /dev/kvm access can create the VM and vCPUs and request KVM_ARM_VCPU_HAS_EL2.\nUI:N - The same process can issue KVM_RUN for the L2 vCPU and KVM_ARM_VCPU_INIT for a newly created vCPU from concurrent threads; no other user must act.\nS:U - The required trigger is the host-side KVM_ARM_VCPU_INIT ioctl, which L2 guest code cannot issue. The demonstrated attack is therefore a /dev/kvm user corrupting the same host kernel, not a guest-to-host escape.\nC:H - After kvm_vcpu_init_nested() frees the old array, vcpu-\u003earch.hw_mmu remains stale; __load_stage2() consumes reclaimable pgd_phys and vtcr fields, while kvm_handle_guest_abort() follows the reclaimable pgt pointer, enabling disclosure of host memory.\nI:H - kvm_handle_guest_abort() passes stale hw_mmu-\u003epgt state to stage-2 mapping operations, and kvm_vcpu_put_hw_mmu() modifies the stale refcnt. Reclaiming the freed object can redirect kernel writes and corrupt host code or data.\nA:H - Dereferencing the freed kvm_s2_mmu through __load_stage2(), nested fault handling, or kvm_vcpu_put_hw_mmu() can cause a host kernel oops or panic."
            }
          ]
        }
      ],
      "providerMetadata": {
        "dateUpdated": "2026-10-24T14:09:32.255Z",
        "orgId": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
        "shortName": "Linux"
      },
      "references": [
        {
          "url": "https://git.kernel.org/stable/c/ea242bdc29e8a8ff0e2447a64b3841114779f3af"
        },
        {
          "url": "https://git.kernel.org/stable/c/81e3f065a6485626f816d791dfd5e00ddd12eff5"
        },
        {
          "url": "https://git.kernel.org/stable/c/512c93f4461b9a3735987f48423d438a9cd49e6a"
        },
        {
          "url": "https://git.kernel.org/stable/c/33346f8960c7bb6a3b4e273b5cfe25c5a8be349f"
        }
      ],
      "title": "KVM: arm64: nv: Fix life cycle of the nested_mmus array",
      "x_generator": {
        "engine": "bippy-1.2.0"
      }
    }
  },
  "cveMetadata": {
    "assignerOrgId": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
    "assignerShortName": "Linux",
    "cveId": "CVE-2026-98927",
    "datePublished": "2026-10-23T12:06:01.528Z",
    "dateReserved": "2026-09-25T10:25:14.380Z",
    "dateUpdated": "2026-10-24T14:09:32.255Z",
    "state": "PUBLISHED"
  },
  "dataType": "CVE_RECORD",
  "dataVersion": "5.2",
  "vulnerability-lookup:meta": {
    "epss": {
      "cve": "CVE-2026-98927",
      "date": "2026-10-24",
      "epss": "0.00209",
      "percentile": "0.10523"
    },
    "microsoft_vex": {
      "current_release_date": "2026-10-24T01:08:07.000Z",
      "cve": "CVE-2026-98927",
      "id": "msrc_CVE-2026-98927",
      "initial_release_date": "2026-10-24T01:08:07.000Z",
      "product_status:under_investigation": "1",
      "source": "Microsoft CSAF VEX",
      "status": "final",
      "title": "KVM: arm64: nv: Fix life cycle of the nested_mmus array",
      "url": "https://msrc.microsoft.com/csaf/vex/2026/msrc_cve-2026-98927.json",
      "version": "1"
    },
    "nvd": {
      "cve": {
        "affected": [
          {
            "affectedData": [
              {
                "defaultStatus": "unaffected",
                "product": "Linux",
                "programFiles": [
                  "arch/arm64/include/asm/kvm_host.h",
                  "arch/arm64/include/asm/kvm_nested.h",
                  "arch/arm64/kvm/arm.c",
                  "arch/arm64/kvm/nested.c"
                ],
                "repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git",
                "vendor": "Linux",
                "versions": [
                  {
                    "lessThan": "ea242bdc29e8a8ff0e2447a64b3841114779f3af",
                    "status": "affected",
                    "version": "4f128f8e1aaac189f83d0f828bcdb2986d8d2e51",
                    "versionType": "git"
                  },
                  {
                    "lessThan": "81e3f065a6485626f816d791dfd5e00ddd12eff5",
                    "status": "affected",
                    "version": "4f128f8e1aaac189f83d0f828bcdb2986d8d2e51",
                    "versionType": "git"
                  },
                  {
                    "lessThan": "512c93f4461b9a3735987f48423d438a9cd49e6a",
                    "status": "affected",
                    "version": "4f128f8e1aaac189f83d0f828bcdb2986d8d2e51",
                    "versionType": "git"
                  },
                  {
                    "lessThan": "33346f8960c7bb6a3b4e273b5cfe25c5a8be349f",
                    "status": "affected",
                    "version": "4f128f8e1aaac189f83d0f828bcdb2986d8d2e51",
                    "versionType": "git"
                  }
                ]
              },
              {
                "defaultStatus": "affected",
                "product": "Linux",
                "programFiles": [
                  "arch/arm64/include/asm/kvm_host.h",
                  "arch/arm64/include/asm/kvm_nested.h",
                  "arch/arm64/kvm/arm.c",
                  "arch/arm64/kvm/nested.c"
                ],
                "repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git",
                "vendor": "Linux",
                "versions": [
                  {
                    "status": "affected",
                    "version": "6.11"
                  },
                  {
                    "lessThan": "6.11",
                    "status": "unaffected",
                    "version": "0",
                    "versionType": "semver"
                  },
                  {
                    "lessThanOrEqual": "6.12.*",
                    "status": "unaffected",
                    "version": "6.12.113",
                    "versionType": "semver"
                  },
                  {
                    "lessThanOrEqual": "6.18.*",
                    "status": "unaffected",
                    "version": "6.18.56",
                    "versionType": "semver"
                  },
                  {
                    "lessThanOrEqual": "7.2.*",
                    "status": "unaffected",
                    "version": "7.2.9",
                    "versionType": "semver"
                  },
                  {
                    "lessThanOrEqual": "*",
                    "status": "unaffected",
                    "version": "7.3",
                    "versionType": "original_commit_for_fix"
                  }
                ]
              }
            ],
            "source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67"
          }
        ],
        "cveTags": [],
        "descriptions": [
          {
            "lang": "en",
            "value": "In the Linux kernel, the following vulnerability has been resolved:\n\nKVM: arm64: nv: Fix life cycle of the nested_mmus array\n\nThe nested_mmus array holds the shadow page tables that are used when\na guest is running a nested context. These structures are allocated on\nVCPU_INIT for whole guest, which implies that they may have to be\nrelocated as the array grows.\n\nShould a VCPU_INIT occur whilst a vcpu is actively running an L2 and\nthat the allocation requires relocation, that vcpu will still be\nrunning with a pointer to the previous structure, which will have been\nfreed.\n\nFix this by turning the array of structures to an array of pointers,\nwhich is now allocated at VM creation, sized to the absolute maximum\nthat KVM can handle.\n\nIn turn, each VCPU_INIT contributes S2_MMU_PER_VCPU to the pool. No\nreallocation is ever performed, and the life cycle of each object is\nmuch clearer:\n\n- the nested_mmus array is allocated in kvm_init_nested(), and freed\n  in kvm_arch_destroy_vm()\n\n- s2_mmu structures are allocated in kvm_vcpu_init_nested(), and freed\n  on kvm_arch_flush_shadow_all()\n\nFinally, the freeing of vcpu-\u003earch.vncr_array is made consistent\nrather than being done on some failure paths, but not others."
          }
        ],
        "id": "CVE-2026-98927",
        "lastModified": "2026-10-24T14:16:48.507",
        "metrics": {
          "cvssMetricV31": [
            {
              "cvssData": {
                "attackComplexity": "HIGH",
                "attackVector": "LOCAL",
                "availabilityImpact": "HIGH",
                "baseScore": 7.0,
                "baseSeverity": "HIGH",
                "confidentialityImpact": "HIGH",
                "integrityImpact": "HIGH",
                "privilegesRequired": "LOW",
                "scope": "UNCHANGED",
                "userInteraction": "NONE",
                "vectorString": "CVSS:3.1/AV:L/AC:H/PR:L/UI:N/S:U/C:H/I:H/A:H",
                "version": "3.1"
              },
              "exploitabilityScore": 1.0,
              "impactScore": 5.9,
              "source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
              "type": "Secondary"
            }
          ]
        },
        "published": "2026-10-23T13:17:13.450",
        "references": [
          {
            "source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
            "url": "https://git.kernel.org/stable/c/33346f8960c7bb6a3b4e273b5cfe25c5a8be349f"
          },
          {
            "source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
            "url": "https://git.kernel.org/stable/c/512c93f4461b9a3735987f48423d438a9cd49e6a"
          },
          {
            "source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
            "url": "https://git.kernel.org/stable/c/81e3f065a6485626f816d791dfd5e00ddd12eff5"
          },
          {
            "source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
            "url": "https://git.kernel.org/stable/c/ea242bdc29e8a8ff0e2447a64b3841114779f3af"
          }
        ],
        "sourceIdentifier": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
        "vulnStatus": "Received"
      }
    }
  }
}

FKIE_CVE-2026-98927

Vulnerability from fkie_nvd - Published: 2026-10-23 13:17 - Updated: 2026-10-24 14:16

Severity

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

Summary

References

	URL	Tags
	416baaa9-dc9f-4396-8d5f-8c081fb06d67	https://git.kernel.org/stable/c/33346f8960c7bb6a3b4e273b5cfe25c5a8be349f
	416baaa9-dc9f-4396-8d5f-8c081fb06d67	https://git.kernel.org/stable/c/512c93f4461b9a3735987f48423d438a9cd49e6a
	416baaa9-dc9f-4396-8d5f-8c081fb06d67	https://git.kernel.org/stable/c/81e3f065a6485626f816d791dfd5e00ddd12eff5
	416baaa9-dc9f-4396-8d5f-8c081fb06d67	https://git.kernel.org/stable/c/ea242bdc29e8a8ff0e2447a64b3841114779f3af

Impacted products

	Vendor	Product	Version

JSON

To clipboard

{
  "affected": [
    {
      "affectedData": [
        {
          "defaultStatus": "unaffected",
          "product": "Linux",
          "programFiles": [
            "arch/arm64/include/asm/kvm_host.h",
            "arch/arm64/include/asm/kvm_nested.h",
            "arch/arm64/kvm/arm.c",
            "arch/arm64/kvm/nested.c"
          ],
          "repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git",
          "vendor": "Linux",
          "versions": [
            {
              "lessThan": "ea242bdc29e8a8ff0e2447a64b3841114779f3af",
              "status": "affected",
              "version": "4f128f8e1aaac189f83d0f828bcdb2986d8d2e51",
              "versionType": "git"
            },
            {
              "lessThan": "81e3f065a6485626f816d791dfd5e00ddd12eff5",
              "status": "affected",
              "version": "4f128f8e1aaac189f83d0f828bcdb2986d8d2e51",
              "versionType": "git"
            },
            {
              "lessThan": "512c93f4461b9a3735987f48423d438a9cd49e6a",
              "status": "affected",
              "version": "4f128f8e1aaac189f83d0f828bcdb2986d8d2e51",
              "versionType": "git"
            },
            {
              "lessThan": "33346f8960c7bb6a3b4e273b5cfe25c5a8be349f",
              "status": "affected",
              "version": "4f128f8e1aaac189f83d0f828bcdb2986d8d2e51",
              "versionType": "git"
            }
          ]
        },
        {
          "defaultStatus": "affected",
          "product": "Linux",
          "programFiles": [
            "arch/arm64/include/asm/kvm_host.h",
            "arch/arm64/include/asm/kvm_nested.h",
            "arch/arm64/kvm/arm.c",
            "arch/arm64/kvm/nested.c"
          ],
          "repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git",
          "vendor": "Linux",
          "versions": [
            {
              "status": "affected",
              "version": "6.11"
            },
            {
              "lessThan": "6.11",
              "status": "unaffected",
              "version": "0",
              "versionType": "semver"
            },
            {
              "lessThanOrEqual": "6.12.*",
              "status": "unaffected",
              "version": "6.12.113",
              "versionType": "semver"
            },
            {
              "lessThanOrEqual": "6.18.*",
              "status": "unaffected",
              "version": "6.18.56",
              "versionType": "semver"
            },
            {
              "lessThanOrEqual": "7.2.*",
              "status": "unaffected",
              "version": "7.2.9",
              "versionType": "semver"
            },
            {
              "lessThanOrEqual": "*",
              "status": "unaffected",
              "version": "7.3",
              "versionType": "original_commit_for_fix"
            }
          ]
        }
      ],
      "source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67"
    }
  ],
  "cveTags": [],
  "descriptions": [
    {
      "lang": "en",
      "value": "In the Linux kernel, the following vulnerability has been resolved:\n\nKVM: arm64: nv: Fix life cycle of the nested_mmus array\n\nThe nested_mmus array holds the shadow page tables that are used when\na guest is running a nested context. These structures are allocated on\nVCPU_INIT for whole guest, which implies that they may have to be\nrelocated as the array grows.\n\nShould a VCPU_INIT occur whilst a vcpu is actively running an L2 and\nthat the allocation requires relocation, that vcpu will still be\nrunning with a pointer to the previous structure, which will have been\nfreed.\n\nFix this by turning the array of structures to an array of pointers,\nwhich is now allocated at VM creation, sized to the absolute maximum\nthat KVM can handle.\n\nIn turn, each VCPU_INIT contributes S2_MMU_PER_VCPU to the pool. No\nreallocation is ever performed, and the life cycle of each object is\nmuch clearer:\n\n- the nested_mmus array is allocated in kvm_init_nested(), and freed\n  in kvm_arch_destroy_vm()\n\n- s2_mmu structures are allocated in kvm_vcpu_init_nested(), and freed\n  on kvm_arch_flush_shadow_all()\n\nFinally, the freeing of vcpu-\u003earch.vncr_array is made consistent\nrather than being done on some failure paths, but not others."
    }
  ],
  "id": "CVE-2026-98927",
  "lastModified": "2026-10-24T14:16:48.507",
  "metrics": {
    "cvssMetricV31": [
      {
        "cvssData": {
          "attackComplexity": "HIGH",
          "attackVector": "LOCAL",
          "availabilityImpact": "HIGH",
          "baseScore": 7.0,
          "baseSeverity": "HIGH",
          "confidentialityImpact": "HIGH",
          "integrityImpact": "HIGH",
          "privilegesRequired": "LOW",
          "scope": "UNCHANGED",
          "userInteraction": "NONE",
          "vectorString": "CVSS:3.1/AV:L/AC:H/PR:L/UI:N/S:U/C:H/I:H/A:H",
          "version": "3.1"
        },
        "exploitabilityScore": 1.0,
        "impactScore": 5.9,
        "source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
        "type": "Secondary"
      }
    ]
  },
  "published": "2026-10-23T13:17:13.450",
  "references": [
    {
      "source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
      "url": "https://git.kernel.org/stable/c/33346f8960c7bb6a3b4e273b5cfe25c5a8be349f"
    },
    {
      "source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
      "url": "https://git.kernel.org/stable/c/512c93f4461b9a3735987f48423d438a9cd49e6a"
    },
    {
      "source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
      "url": "https://git.kernel.org/stable/c/81e3f065a6485626f816d791dfd5e00ddd12eff5"
    },
    {
      "source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
      "url": "https://git.kernel.org/stable/c/ea242bdc29e8a8ff0e2447a64b3841114779f3af"
    }
  ],
  "sourceIdentifier": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
  "vulnStatus": "Received"
}

GHSA-2374-8V6X-X95C

Vulnerability from github – Published: 2026-10-23 15:31 – Updated: 2026-10-24 15:32

Details

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

KVM: arm64: nv: Fix life cycle of the nested_mmus array

The nested_mmus array holds the shadow page tables that are used when a guest is running a nested context. These structures are allocated on VCPU_INIT for whole guest, which implies that they may have to be relocated as the array grows.

Should a VCPU_INIT occur whilst a vcpu is actively running an L2 and that the allocation requires relocation, that vcpu will still be running with a pointer to the previous structure, which will have been freed.

Fix this by turning the array of structures to an array of pointers, which is now allocated at VM creation, sized to the absolute maximum that KVM can handle.

In turn, each VCPU_INIT contributes S2_MMU_PER_VCPU to the pool. No reallocation is ever performed, and the life cycle of each object is much clearer:

the nested_mmus array is allocated in kvm_init_nested(), and freed in kvm_arch_destroy_vm()
s2_mmu structures are allocated in kvm_vcpu_init_nested(), and freed on kvm_arch_flush_shadow_all()

Finally, the freeing of vcpu->arch.vncr_array is made consistent rather than being done on some failure paths, but not others.

Severity

7.0 (High)


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

Show details on source website

JSON

To clipboard

{
  "affected": [],
  "aliases": [
    "CVE-2026-98927"
  ],
  "database_specific": {
    "cwe_ids": [],
    "github_reviewed": false,
    "github_reviewed_at": null,
    "nvd_published_at": "2026-10-23T13:17:13Z",
    "severity": "HIGH"
  },
  "details": "In the Linux kernel, the following vulnerability has been resolved:\n\nKVM: arm64: nv: Fix life cycle of the nested_mmus array\n\nThe nested_mmus array holds the shadow page tables that are used when\na guest is running a nested context. These structures are allocated on\nVCPU_INIT for whole guest, which implies that they may have to be\nrelocated as the array grows.\n\nShould a VCPU_INIT occur whilst a vcpu is actively running an L2 and\nthat the allocation requires relocation, that vcpu will still be\nrunning with a pointer to the previous structure, which will have been\nfreed.\n\nFix this by turning the array of structures to an array of pointers,\nwhich is now allocated at VM creation, sized to the absolute maximum\nthat KVM can handle.\n\nIn turn, each VCPU_INIT contributes S2_MMU_PER_VCPU to the pool. No\nreallocation is ever performed, and the life cycle of each object is\nmuch clearer:\n\n- the nested_mmus array is allocated in kvm_init_nested(), and freed\n  in kvm_arch_destroy_vm()\n\n- s2_mmu structures are allocated in kvm_vcpu_init_nested(), and freed\n  on kvm_arch_flush_shadow_all()\n\nFinally, the freeing of vcpu-\u003earch.vncr_array is made consistent\nrather than being done on some failure paths, but not others.",
  "id": "GHSA-2374-8v6x-x95c",
  "modified": "2026-10-24T15:32:47Z",
  "published": "2026-10-23T15:31:31Z",
  "references": [
    {
      "type": "ADVISORY",
      "url": "https://nvd.nist.gov/vuln/detail/CVE-2026-98927"
    },
    {
      "type": "WEB",
      "url": "https://git.kernel.org/stable/c/33346f8960c7bb6a3b4e273b5cfe25c5a8be349f"
    },
    {
      "type": "WEB",
      "url": "https://git.kernel.org/stable/c/512c93f4461b9a3735987f48423d438a9cd49e6a"
    },
    {
      "type": "WEB",
      "url": "https://git.kernel.org/stable/c/81e3f065a6485626f816d791dfd5e00ddd12eff5"
    },
    {
      "type": "WEB",
      "url": "https://git.kernel.org/stable/c/ea242bdc29e8a8ff0e2447a64b3841114779f3af"
    }
  ],
  "schema_version": "1.4.0",
  "severity": [
    {
      "score": "CVSS:3.1/AV:L/AC:H/PR:L/UI:N/S:U/C:H/I:H/A:H",
      "type": "CVSS_V3"
    }
  ]
}

MSRC_CVE-2026-98927

Vulnerability from csaf_microsoft - Published: 2026-10-24 01:08 - Updated: 2026-10-24 01:08

Summary

KVM: arm64: nv: Fix life cycle of the nested_mmus array

Scope

1 vulnerability in this advisory, including CVE-2026-98927.

CVE-2026-98927

Under investigation: 1 product

Open the full advisory

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Author	Source	Type	Date	Other

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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.

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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.
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CVE-2026-98927 (GCVE-0-2026-98927)

FKIE_CVE-2026-98927

GHSA-2374-8V6X-X95C

MSRC_CVE-2026-98927

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