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CVE-2019-15794

Estado: ModificadaMedia (6.7)—💥 Exploit

Overlayfs in the Linux kernel and shiftfs, a non-upstream patch to the Linux kernel included in the Ubuntu 5.0 and 5.3 kernel series, both replace vma->vm_file in their mmap handlers. On error the original value is not restored, and the reference is put for the file to which vm_file points. On upstream kernels this is not an issue, as no callers dereference vm_file following after call_mmap() returns an error. However, the aufs patchs change mmap_region() to replace the fput() using a local variable with vma_fput(), which will fput() vm_file, leading to a refcount underflow.

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).

💥 Exploits públicos

Hay código de explotación o plantillas de detección públicos. No es lo mismo que explotación activa confirmada (KEV), pero aumenta el riesgo: parchee con prioridad.

Tecnologías afectadas (2)

Canonical — Ubuntu LinuxLinux — Linux Kernel

CWE

Referencias

JSON original (NVD)

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          "vectorString": "AV:L/AC:L/Au:N/C:C/I:C/A:C",
          "authentication": "NONE",
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    },
    {
      "lang": "es",
      "value": "Overlayfs en el kernel de Linux y shiftfs, un parche no upstream para el kernel de Linux incluido en las series de kernel Ubuntu versiones 5.0 y 5.3, ambos reemplazan vma->vm_file en sus manejadores de mmap. En el error el valor original no se restaura, y se pone la referencia para el archivo al que apunta vm_file. En los núcleos ascendentes esto no es un problema, ya que ninguna de las llamadas que siguen a vm_file después de call_mmap() devuelve un error. Sin embargo, los parches de aufs cambian mmap_region() para reemplazar el fput() usando una variable local con vma_fput(), la cual fput() vm_file, lo que lleva a un subflujo de recuento."
    }
  ],
  "lastModified": "2026-06-17T02:21:05.330",
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