FKIE_CVE-2026-46147

Vulnerability from fkie_nvd - Published: 2026-05-28 10:16 - Updated: 2026-06-17 10:53
Severity
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: arm64: Fix pin leak and publication ordering in __pkvm_init_vcpu() Two bugs exist in the vCPU initialisation path: 1. If a check fails after hyp_pin_shared_mem() succeeds, the cleanup path jumps to 'unlock' without calling unpin_host_vcpu() or unpin_host_sve_state(), permanently leaking pin references on the host vCPU and SVE state pages. Extract a register_hyp_vcpu() helper that performs the checks and the store. When register_hyp_vcpu() returns an error, call unpin_host_vcpu() and unpin_host_sve_state() inline before falling through to the existing 'unlock' label. 2. register_hyp_vcpu() publishes the new vCPU pointer into 'hyp_vm->vcpus[]' with a bare store, allowing a concurrent caller of pkvm_load_hyp_vcpu() to observe a partially initialised vCPU object. Ensure the store uses smp_store_release() and the load uses smp_load_acquire(). While 'vm_table_lock' currently serialises the store and the load, these barriers ensure the reader sees the fully initialised 'hyp_vcpu' object even if there were a lockless path or if the lock's own ordering guarantees were insufficient for nested object initialization.
References
416baaa9-dc9f-4396-8d5f-8c081fb06d67https://git.kernel.org/stable/c/6d69c0ed978f7f0efd053fc98390f25ab77c1aeaPatch
416baaa9-dc9f-4396-8d5f-8c081fb06d67https://git.kernel.org/stable/c/73b9c1e5da84cd69b1a86e374e450817cd051371Patch
416baaa9-dc9f-4396-8d5f-8c081fb06d67https://git.kernel.org/stable/c/7d3c27b54253cda91dc4d2c1bfc109c490837ab9Patch
Impacted products
Vendor Product Version
linux linux_kernel *
linux linux_kernel *
linux linux_kernel 7.1
To clipboard 

{
  "affected": [
    {
      "affectedData": [
        {
          "defaultStatus": "unaffected",
          "product": "Linux",
          "programFiles": [
            "arch/arm64/kvm/hyp/nvhe/pkvm.c"
          ],
          "repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git",
          "vendor": "Linux",
          "versions": [
            {
              "lessThan": "7d3c27b54253cda91dc4d2c1bfc109c490837ab9",
              "status": "affected",
              "version": "1da177e4c3f41524e886b7f1b8a0c1fc7321cac2",
              "versionType": "git"
            },
            {
              "lessThan": "6d69c0ed978f7f0efd053fc98390f25ab77c1aea",
              "status": "affected",
              "version": "1da177e4c3f41524e886b7f1b8a0c1fc7321cac2",
              "versionType": "git"
            },
            {
              "lessThan": "73b9c1e5da84cd69b1a86e374e450817cd051371",
              "status": "affected",
              "version": "1da177e4c3f41524e886b7f1b8a0c1fc7321cac2",
              "versionType": "git"
            },
            {
              "lessThan": "6.18.30",
              "status": "affected",
              "version": "0",
              "versionType": "semver"
            },
            {
              "lessThan": "7.0.7",
              "status": "affected",
              "version": "0",
              "versionType": "semver"
            }
          ]
        },
        {
          "defaultStatus": "affected",
          "product": "Linux",
          "programFiles": [
            "arch/arm64/kvm/hyp/nvhe/pkvm.c"
          ],
          "repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git",
          "vendor": "Linux",
          "versions": [
            {
              "lessThanOrEqual": "6.18.*",
              "status": "unaffected",
              "version": "6.18.30",
              "versionType": "semver"
            },
            {
              "lessThanOrEqual": "7.0.*",
              "status": "unaffected",
              "version": "7.0.7",
              "versionType": "semver"
            },
            {
              "lessThanOrEqual": "*",
              "status": "unaffected",
              "version": "7.1",
              "versionType": "original_commit_for_fix"
            }
          ]
        }
      ],
      "source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67"
    }
  ],
  "configurations": [
    {
      "nodes": [
        {
          "cpeMatch": [
            {
              "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*",
              "matchCriteriaId": "B2F7049B-B157-4797-BBC1-82A75717CDEC",
              "versionEndExcluding": "6.18.30",
              "vulnerable": true
            },
            {
              "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*",
              "matchCriteriaId": "D0893CA7-9AE6-4DFE-AC75-48967D73AD8E",
              "versionEndExcluding": "7.0.7",
              "versionStartIncluding": "6.19",
              "vulnerable": true
            },
            {
              "criteria": "cpe:2.3:o:linux:linux_kernel:7.1:rc1:*:*:*:*:*:*",
              "matchCriteriaId": "B1EF7059-E670-45F4-B422-54C40FA86390",
              "vulnerable": true
            }
          ],
          "negate": false,
          "operator": "OR"
        }
      ]
    }
  ],
  "cveTags": [],
  "descriptions": [
    {
      "lang": "en",
      "value": "In the Linux kernel, the following vulnerability has been resolved:\n\nKVM: arm64: Fix pin leak and publication ordering in __pkvm_init_vcpu()\n\nTwo bugs exist in the vCPU initialisation path:\n\n1. If a check fails after hyp_pin_shared_mem() succeeds, the cleanup\n   path jumps to \u0027unlock\u0027 without calling unpin_host_vcpu() or\n   unpin_host_sve_state(), permanently leaking pin references on the\n   host vCPU and SVE state pages.\n\n   Extract a register_hyp_vcpu() helper that performs the checks and\n   the store. When register_hyp_vcpu() returns an error, call\n   unpin_host_vcpu() and unpin_host_sve_state() inline before falling\n   through to the existing \u0027unlock\u0027 label.\n\n2. register_hyp_vcpu() publishes the new vCPU pointer into\n   \u0027hyp_vm-\u003evcpus[]\u0027 with a bare store, allowing a concurrent caller\n   of pkvm_load_hyp_vcpu() to observe a partially initialised vCPU\n   object.\n\n   Ensure the store uses smp_store_release() and the load uses\n   smp_load_acquire(). While \u0027vm_table_lock\u0027 currently serialises the\n   store and the load, these barriers ensure the reader sees the fully\n   initialised \u0027hyp_vcpu\u0027 object even if there were a lockless path or\n   if the lock\u0027s own ordering guarantees were insufficient for nested\n   object initialization."
    }
  ],
  "id": "CVE-2026-46147",
  "lastModified": "2026-06-17T10:53:08.980",
  "metrics": {
    "cvssMetricV31": [
      {
        "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": "2026-05-28T10:16:30.320",
  "references": [
    {
      "source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
      "tags": [
        "Patch"
      ],
      "url": "https://git.kernel.org/stable/c/6d69c0ed978f7f0efd053fc98390f25ab77c1aea"
    },
    {
      "source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
      "tags": [
        "Patch"
      ],
      "url": "https://git.kernel.org/stable/c/73b9c1e5da84cd69b1a86e374e450817cd051371"
    },
    {
      "source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
      "tags": [
        "Patch"
      ],
      "url": "https://git.kernel.org/stable/c/7d3c27b54253cda91dc4d2c1bfc109c490837ab9"
    }
  ],
  "sourceIdentifier": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
  "vulnStatus": "Analyzed",
  "weaknesses": [
    {
      "description": [
        {
          "lang": "en",
          "value": "CWE-401"
        }
      ],
      "source": "nvd@nist.gov",
      "type": "Primary"
    }
  ]
}


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