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CVE-2026-74716

Estado: RecibidaSin puntuar—

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

accel/amdxdna: Fix locally exploitable BUG_ON in amdxdna_insert_pages()

In amdxdna_insert_pages(), vm_flags_mod() sets VM_MIXEDMAP and clears VM_PFNMAP. If an unprivileged userspace process mmaps a non-imported GEM object and then calls madvise(MADV_DONTNEED), the PTEs will be successfully cleared because VM_MIXEDMAP allows this (unlike VM_PFNMAP).

When userspace subsequently accesses the memory, drm_gem_shmem_fault() handles the page fault and attempts to map the backing shmem page via vmf_insert_pfn() which calls vmf_insert_pfn_prot().

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Because the backing shmem page is normal system memory (pfn_valid(pfn) is true) and the VMA now has VM_MIXEDMAP set, won't this predictably trigger the explicit assertion BUG_ON((vma->vm_flags & VM_MIXEDMAP) && pfn_valid(pfn))

Fix by removing the vm_flags_mod() call and replacing the vm_insert_pages() pre-population with the handle_mm_fault() loop that was already used for the import (dma-buf) path.

CVSS

NVD no ha asignado puntuación CVSS a esta CVE (habitual desde el cambio de política de abril de 2026).

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)

⚠ Inferidas por IA a partir de la descripción — NVD aún no ha analizado esta CVE; no son CPE verificados.

Linux — Linux KernelAI

Referencias

JSON original (NVD)

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{
  "id": "CVE-2026-74716",
  "cveTags": [],
  "metrics": {},
  "affected": [
    {
      "source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
      "affectedData": [
        {
          "repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git",
          "vendor": "Linux",
          "product": "Linux",
          "versions": [
            {
              "status": "affected",
              "version": "e486147c912f653ef4b60a6c7dbd4168a4c56a9f",
              "lessThan": "13339132d89d00b513dff0730bff3a313b9b13b5",
              "versionType": "git"
            },
            {
              "status": "affected",
              "version": "e486147c912f653ef4b60a6c7dbd4168a4c56a9f",
              "lessThan": "4a19f7ab5972ef608b31ae921419bc3e04b3f8ad",
              "versionType": "git"
            }
          ],
          "programFiles": [
            "drivers/accel/amdxdna/amdxdna_gem.c"
          ],
          "defaultStatus": "unaffected"
        },
        {
          "repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git",
          "vendor": "Linux",
          "product": "Linux",
          "versions": [
            {
              "status": "affected",
              "version": "6.16"
            },
            {
              "status": "unaffected",
              "version": "0",
              "lessThan": "6.16",
              "versionType": "semver"
            },
            {
              "status": "unaffected",
              "version": "7.1.9",
              "versionType": "semver",
              "lessThanOrEqual": "7.1.*"
            },
            {
              "status": "unaffected",
              "version": "7.2",
              "versionType": "original_commit_for_fix",
              "lessThanOrEqual": "*"
            }
          ],
          "programFiles": [
            "drivers/accel/amdxdna/amdxdna_gem.c"
          ],
          "defaultStatus": "affected"
        }
      ]
    }
  ],
  "published": "2026-08-22T16:16:46.443",
  "references": [
    {
      "url": "https://git.kernel.org/stable/c/13339132d89d00b513dff0730bff3a313b9b13b5",
      "source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67"
    },
    {
      "url": "https://git.kernel.org/stable/c/4a19f7ab5972ef608b31ae921419bc3e04b3f8ad",
      "source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67"
    }
  ],
  "vulnStatus": "Received",
  "descriptions": [
    {
      "lang": "en",
      "value": "In the Linux kernel, the following vulnerability has been resolved:\n\naccel/amdxdna: Fix locally exploitable BUG_ON in amdxdna_insert_pages()\n\nIn amdxdna_insert_pages(), vm_flags_mod() sets VM_MIXEDMAP and clears\nVM_PFNMAP. If an unprivileged userspace process mmaps a non-imported GEM\nobject and then calls madvise(MADV_DONTNEED), the PTEs will be\nsuccessfully cleared because VM_MIXEDMAP allows this (unlike VM_PFNMAP).\n\nWhen userspace subsequently accesses the memory, drm_gem_shmem_fault()\nhandles the page fault and attempts to map the backing shmem page via\nvmf_insert_pfn() which calls vmf_insert_pfn_prot(). Because the backing\nshmem page is normal system memory (pfn_valid(pfn) is true) and the VMA\nnow has VM_MIXEDMAP set, won't this predictably trigger the explicit\nassertion BUG_ON((vma->vm_flags & VM_MIXEDMAP) && pfn_valid(pfn))\n\nFix by removing the vm_flags_mod() call and replacing the vm_insert_pages()\npre-population with the handle_mm_fault() loop that was already used for\nthe import (dma-buf) path."
    }
  ],
  "lastModified": "2026-08-22T16:16:46.443",
  "sourceIdentifier": "416baaa9-dc9f-4396-8d5f-8c081fb06d67"
}