CVE-2026-98927

Full vulnerability record from the local CVENow database.

Description

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

HIGH

CVSS score

7.0 (v3.1)

Vulnerability status

Received

Source identifier

416baaa9-dc9f-4396-8d5f-8c081fb06d67

Published

2026-10-23 13:17:13.450000

Last modified

2026-10-24 14:16:48.507000

View original CVE JSON

{
  "id": "CVE-2026-98927",
  "sourceIdentifier": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
  "published": "2026-10-23T13:17:13.450",
  "lastModified": "2026-10-24T14:16:48.507",
  "vulnStatus": "Received",
  "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->arch.vncr_array is made consistent\nrather than being done on some failure paths, but not others."
    }
  ],
  "affected": [
    {
      "source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
      "affectedData": [
        {
          "vendor": "Linux",
          "product": "Linux",
          "defaultStatus": "unaffected",
          "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",
          "versions": [
            {
              "version": "4f128f8e1aaac189f83d0f828bcdb2986d8d2e51",
              "lessThan": "ea242bdc29e8a8ff0e2447a64b3841114779f3af",
              "versionType": "git",
              "status": "affected"
            },
            {
              "version": "4f128f8e1aaac189f83d0f828bcdb2986d8d2e51",
              "lessThan": "81e3f065a6485626f816d791dfd5e00ddd12eff5",
              "versionType": "git",
              "status": "affected"
            },
            {
              "version": "4f128f8e1aaac189f83d0f828bcdb2986d8d2e51",
              "lessThan": "512c93f4461b9a3735987f48423d438a9cd49e6a",
              "versionType": "git",
              "status": "affected"
            },
            {
              "version": "4f128f8e1aaac189f83d0f828bcdb2986d8d2e51",
              "lessThan": "33346f8960c7bb6a3b4e273b5cfe25c5a8be349f",
              "versionType": "git",
              "status": "affected"
            }
          ]
        },
        {
          "vendor": "Linux",
          "product": "Linux",
          "defaultStatus": "affected",
          "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",
          "versions": [
            {
              "version": "6.11",
              "status": "affected"
            },
            {
              "version": "0",
              "lessThan": "6.11",
              "versionType": "semver",
              "status": "unaffected"
            },
            {
              "version": "6.12.113",
              "lessThanOrEqual": "6.12.*",
              "versionType": "semver",
              "status": "unaffected"
            },
            {
              "version": "6.18.56",
              "lessThanOrEqual": "6.18.*",
              "versionType": "semver",
              "status": "unaffected"
            },
            {
              "version": "7.2.9",
              "lessThanOrEqual": "7.2.*",
              "versionType": "semver",
              "status": "unaffected"
            },
            {
              "version": "7.3",
              "lessThanOrEqual": "*",
              "versionType": "original_commit_for_fix",
              "status": "unaffected"
            }
          ]
        }
      ]
    }
  ],
  "metrics": {
    "cvssMetricV31": [
      {
        "source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
        "type": "Secondary",
        "cvssData": {
          "version": "3.1",
          "vectorString": "CVSS:3.1/AV:L/AC:H/PR:L/UI:N/S:U/C:H/I:H/A:H",
          "baseScore": 7.0,
          "baseSeverity": "HIGH",
          "attackVector": "LOCAL",
          "attackComplexity": "HIGH",
          "privilegesRequired": "LOW",
          "userInteraction": "NONE",
          "scope": "UNCHANGED",
          "confidentialityImpact": "HIGH",
          "integrityImpact": "HIGH",
          "availabilityImpact": "HIGH"
        },
        "exploitabilityScore": 1.0,
        "impactScore": 5.9
      }
    ]
  },
  "references": [
    {
      "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",
      "source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67"
    }
  ]
}