{
  "id": "CVE-2022-49562",
  "sourceIdentifier": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
  "published": "2025-02-26T07:01:31.970",
  "lastModified": "2025-02-26T07:01:31.970",
  "vulnStatus": "Awaiting Analysis",
  "cveTags": [],
  "descriptions": [
    {
      "lang": "en",
      "value": "In the Linux kernel, the following vulnerability has been resolved:\n\nKVM: x86: Use __try_cmpxchg_user() to update guest PTE A/D bits\n\nUse the recently introduced __try_cmpxchg_user() to update guest PTE A/D\nbits instead of mapping the PTE into kernel address space.  The VM_PFNMAP\npath is broken as it assumes that vm_pgoff is the base pfn of the mapped\nVMA range, which is conceptually wrong as vm_pgoff is the offset relative\nto the file and has nothing to do with the pfn.  The horrific hack worked\nfor the original use case (backing guest memory with /dev/mem), but leads\nto accessing \"random\" pfns for pretty much any other VM_PFNMAP case."
    },
    {
      "lang": "es",
      "value": "En el kernel de Linux, se ha resuelto la siguiente vulnerabilidad: KVM: x86: Use __try_cmpxchg_user() para actualizar los bits A/D de la PTE invitada Use la recientemente introducida __try_cmpxchg_user() para actualizar los bits A/D de la PTE invitada en lugar de mapear la PTE en el espacio de direcciones del kernel. La ruta VM_PFNMAP est\u00e1 rota ya que asume que vm_pgoff es la pfn base del rango VMA mapeado, lo cual es conceptualmente incorrecto ya que vm_pgoff es el desplazamiento relativo al archivo y no tiene nada que ver con la pfn. El horrible hack funcion\u00f3 para el caso de uso original (respaldar la memoria invitada con /dev/mem), pero conduce al acceso a pfn \"aleatorios\" para pr\u00e1cticamente cualquier otro caso VM_PFNMAP."
    }
  ],
  "metrics": {},
  "references": [
    {
      "url": "https://git.kernel.org/stable/c/38b888911e8dc89b89d8147cfb1d2dbe6373bf78",
      "source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67"
    },
    {
      "url": "https://git.kernel.org/stable/c/8089e5e1d18402fb8152d6b6815450a36fffa9b0",
      "source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67"
    },
    {
      "url": "https://git.kernel.org/stable/c/f122dfe4476890d60b8c679128cd2259ec96a24c",
      "source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67"
    }
  ]
}