FKIE_CVE-2026-74721

Vulnerability from fkie_nvd - Published: 2026-08-22 16:16 - Updated: 2026-10-15 11:17
Severity
7.8 (High) - CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H
Summary
In the Linux kernel, the following vulnerability has been resolved: accel/amxdna: Fix page-insertion errors in amdxdna_insert_pages() Two error paths in amdxdna_insert_pages() called vma->vm_ops->close(vma) before returning an error code to the caller. This is incorrect: amdxdna_gem_obj_mmap() registers an HMM interval notifier before calling amdxdna_insert_pages(), and on a hard error it jumps to hmm_unreg to undo that registration. Calling vm_ops->close() manually — which drops the shmem pages_pin_count and the GEM object reference that backs the VMA — before the mmap syscall has even returned causes those resources to be released while the VMA is still alive. The kernel VMA teardown will call vm_ops->close() a second time when the process later unmaps the range, producing a reference count underflow. Replace both hard-error returns with a deferred-fault approach that keeps the VMA alive and retries page insertion through the HMM range-fault path.
References
416baaa9-dc9f-4396-8d5f-8c081fb06d67https://git.kernel.org/stable/c/1501e4d07c6fee0d50531a0d1cb2be01a63e6e75
416baaa9-dc9f-4396-8d5f-8c081fb06d67https://git.kernel.org/stable/c/8d51e0fd3e698919d2adeff71936377f0c0d4aa0
416baaa9-dc9f-4396-8d5f-8c081fb06d67https://git.kernel.org/stable/c/b3d05a335cbd3d89538e9dde1621dccf33ae945a
Impacted products
Vendor Product Version
To clipboard 

{
  "affected": [
    {
      "affectedData": [
        {
          "defaultStatus": "unaffected",
          "product": "Linux",
          "programFiles": [
            "drivers/accel/amdxdna/amdxdna_gem.c"
          ],
          "repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git",
          "vendor": "Linux",
          "versions": [
            {
              "lessThan": "b3d05a335cbd3d89538e9dde1621dccf33ae945a",
              "status": "affected",
              "version": "e486147c912f653ef4b60a6c7dbd4168a4c56a9f",
              "versionType": "git"
            },
            {
              "lessThan": "1501e4d07c6fee0d50531a0d1cb2be01a63e6e75",
              "status": "affected",
              "version": "e486147c912f653ef4b60a6c7dbd4168a4c56a9f",
              "versionType": "git"
            },
            {
              "lessThan": "8d51e0fd3e698919d2adeff71936377f0c0d4aa0",
              "status": "affected",
              "version": "e486147c912f653ef4b60a6c7dbd4168a4c56a9f",
              "versionType": "git"
            }
          ]
        },
        {
          "defaultStatus": "affected",
          "product": "Linux",
          "programFiles": [
            "drivers/accel/amdxdna/amdxdna_gem.c"
          ],
          "repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git",
          "vendor": "Linux",
          "versions": [
            {
              "status": "affected",
              "version": "6.16"
            },
            {
              "lessThan": "6.16",
              "status": "unaffected",
              "version": "0",
              "versionType": "semver"
            },
            {
              "lessThanOrEqual": "6.18.*",
              "status": "unaffected",
              "version": "6.18.57",
              "versionType": "semver"
            },
            {
              "lessThanOrEqual": "7.1.*",
              "status": "unaffected",
              "version": "7.1.9",
              "versionType": "semver"
            },
            {
              "lessThanOrEqual": "*",
              "status": "unaffected",
              "version": "7.2",
              "versionType": "original_commit_for_fix"
            }
          ]
        }
      ],
      "source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67"
    }
  ],
  "cveTags": [],
  "descriptions": [
    {
      "lang": "en",
      "value": "In the Linux kernel, the following vulnerability has been resolved:\n\naccel/amxdna: Fix page-insertion errors in amdxdna_insert_pages()\n\nTwo error paths in amdxdna_insert_pages() called vma-\u003evm_ops-\u003eclose(vma)\nbefore returning an error code to the caller.  This is incorrect:\namdxdna_gem_obj_mmap() registers an HMM interval notifier before calling\namdxdna_insert_pages(), and on a hard error it jumps to hmm_unreg to undo\nthat registration.  Calling vm_ops-\u003eclose() manually \u2014 which drops the\nshmem pages_pin_count and the GEM object reference that backs the VMA \u2014\nbefore the mmap syscall has even returned causes those resources to be\nreleased while the VMA is still alive.  The kernel VMA teardown will call\nvm_ops-\u003eclose() a second time when the process later unmaps the range,\nproducing a reference count underflow.\n\nReplace both hard-error returns with a deferred-fault approach that keeps\nthe VMA alive and retries page insertion through the HMM range-fault path."
    },
    {
      "lang": "es",
      "value": "En el kernel de Linux, la siguiente vulnerabilidad ha sido resuelta:\n\naccel/amxdna: Corrige errores de inserci\u00f3n de p\u00e1gina en amdxdna_insert_pages()\n\nDos rutas de error en amdxdna_insert_pages() llamaron a vma -\u003e vm_ops -\u003e close(vma) antes de devolver un c\u00f3digo de error al llamador. Esto es incorrecto: amdxdna_gem_obj_mmap() registra un notificador de intervalo HMM antes de llamar a amdxdna_insert_pages(), y en un error grave salta a hmm_unreg para deshacer ese registro. Llamar a vm_ops -\u003e close() manualmente - lo que reduce el pages_pin_count de shmem y la referencia al objeto GEM que respalda el VMA - antes de que la llamada al sistema mmap haya siquiera regresado hace que esos recursos sean liberados mientras el VMA a\u00fan est\u00e1 activo. La desestructuraci\u00f3n del VMA del kernel llamar\u00e1 a vm_ops -\u003e close() una segunda vez cuando el proceso desmapee el rango m\u00e1s tarde, produciendo un desbordamiento negativo del contador de referencias.\n\nReemplaza ambas devoluciones de error grave con un enfoque de fallo diferido que mantiene el VMA activo y reintenta la inserci\u00f3n de p\u00e1gina a trav\u00e9s de la ruta de fallo de rango HMM."
    }
  ],
  "id": "CVE-2026-74721",
  "lastModified": "2026-10-15T11:17:48.843",
  "metrics": {
    "cvssMetricV31": [
      {
        "cvssData": {
          "attackComplexity": "LOW",
          "attackVector": "LOCAL",
          "availabilityImpact": "HIGH",
          "baseScore": 7.8,
          "baseSeverity": "HIGH",
          "confidentialityImpact": "HIGH",
          "integrityImpact": "HIGH",
          "privilegesRequired": "LOW",
          "scope": "UNCHANGED",
          "userInteraction": "NONE",
          "vectorString": "CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H",
          "version": "3.1"
        },
        "exploitabilityScore": 1.8,
        "impactScore": 5.9,
        "source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
        "type": "Secondary"
      }
    ]
  },
  "published": "2026-08-22T16:16:47.080",
  "references": [
    {
      "source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
      "url": "https://git.kernel.org/stable/c/1501e4d07c6fee0d50531a0d1cb2be01a63e6e75"
    },
    {
      "source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
      "url": "https://git.kernel.org/stable/c/8d51e0fd3e698919d2adeff71936377f0c0d4aa0"
    },
    {
      "source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
      "url": "https://git.kernel.org/stable/c/b3d05a335cbd3d89538e9dde1621dccf33ae945a"
    }
  ],
  "sourceIdentifier": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
  "vulnStatus": "Received"
}



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