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CVE-2026-46317

Estado: AnalizadaAlta (8.8)—

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

KVM: arm64: Reassign nested_mmus array behind mmu_lock

kvm->arch.nested_mmus[] is walked under kvm->mmu_lock, including from the MMU notifier path (kvm_unmap_gfn_range() -> kvm_nested_s2_unmap()), which can run at any time. kvm_vcpu_init_nested() reallocates the array and frees the old buffer while holding only kvm->arch.config_lock, so such a walker can reference the freed array.

Allocate the new array outside of mmu_lock, as the allocation can sleep. Under the lock, copy the existing entries, fix up the back pointers and reassign the array. Free the old buffer after dropping the lock, as kvfree() can sleep as well.

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).

🎯 Técnicas ATT&CK

Cómo se explota esta vulnerabilidad y qué consigue el atacante, en el lenguaje de MITRE ATT&CK.

AV:L PR:L sin UI permite escalada local tras acceso inicial. La race condition en nested_mmus permite lectura/escrité de memoria de kernel (C:H I:H) y potencial DoS (A:H) o ejecución de código en el contexto del kernel.

Inferido por nuestro agente de análisis a partir de la descripción oficial, el vector CVSS y la CWE, y comprobado por un supervisor. Puede contener errores.

🛡️ Mitigaciones ATT&CK que cubren estas técnicas

Execution PreventionThreat Intelligence ProgramRestrict Web-Based ContentPrivileged Account ManagementLimit Software InstallationFilter Network Traffic

Tecnologías afectadas (1)

Linux — Linux Kernel

CWE

Referencias

JSON original (NVD)

Mostrar
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      "value": "In the Linux kernel, the following vulnerability has been resolved:\n\nKVM: arm64: Reassign nested_mmus array behind mmu_lock\n\nkvm->arch.nested_mmus[] is walked under kvm->mmu_lock, including from the\nMMU notifier path (kvm_unmap_gfn_range() -> kvm_nested_s2_unmap()), which\ncan run at any time. kvm_vcpu_init_nested() reallocates the array and frees\nthe old buffer while holding only kvm->arch.config_lock, so such a walker\ncan reference the freed array.\n\nAllocate the new array outside of mmu_lock, as the allocation can sleep.\nUnder the lock, copy the existing entries, fix up the back pointers and\nreassign the array. Free the old buffer after dropping the lock, as\nkvfree() can sleep as well."
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      "value": "En el kernel de Linux, la siguiente vulnerabilidad ha sido resuelta:\n\nKVM: arm64: Reasignar el array nested_mmus detrás de mmu_lock\n\nkvm->arch.nested_mmus[] es recorrido bajo kvm->mmu_lock, incluyendo desde la ruta del notificador de MMU (kvm_unmap_gfn_range() -> kvm_nested_s2_unmap()), que puede ejecutarse en cualquier momento. kvm_vcpu_init_nested() reasigna el array y libera el búfer antiguo mientras mantiene solo kvm->arch.config_lock, por lo que dicho recorredor puede referenciar el array liberado.\n\nAsignar el nuevo array fuera de mmu_lock, ya que la asignación puede dormir. Bajo el bloqueo, copiar las entradas existentes, corregir los punteros inversos y reasignar el array. Liberar el búfer antiguo después de soltar el bloqueo, ya que kvfree() también puede dormir."
    }
  ],
  "lastModified": "2026-07-23T08:10:00.137",
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