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CVE-2026-46147

Estado: AnalizadaMedia (5.5)—

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:

Detalles técnicos trazas, registros y código del informe original
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.

CVSS

Probabilidad de explotación (EPSS)

EPSS (Exploit Prediction Scoring System, de FIRST) estima la probabilidad de que una vulnerabilidad sea explotada en 30 días. Complementa a CVSS (impacto) y a CISA KEV (explotación confirmada).

Tecnologías afectadas (1)

Linux — Linux Kernel

CWE

Referencias

JSON original (NVD)

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  "id": "CVE-2026-46147",
  "cveTags": [],
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          "attackVector": "LOCAL",
          "baseSeverity": "MEDIUM",
          "vectorString": "CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:H",
          "integrityImpact": "NONE",
          "userInteraction": "NONE",
          "attackComplexity": "LOW",
          "availabilityImpact": "HIGH",
          "privilegesRequired": "LOW",
          "confidentialityImpact": "NONE"
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  "published": "2026-05-28T10:16:30.320",
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          "value": "CWE-401"
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  "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 'unlock' 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 'unlock' label.\n\n2. register_hyp_vcpu() publishes the new vCPU pointer into\n   'hyp_vm->vcpus[]' 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 'vm_table_lock' currently serialises the\n   store and the load, these barriers ensure the reader sees the fully\n   initialised 'hyp_vcpu' object even if there were a lockless path or\n   if the lock's own ordering guarantees were insufficient for nested\n   object initialization."
    }
  ],
  "lastModified": "2026-06-17T10:53:08.980",
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}