FKIE_CVE-2026-74716

Vulnerability from fkie_nvd - Published: 2026-08-22 16:16 - Updated: 2026-08-22 16:16
Severity
Summary
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(). 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.
References
416baaa9-dc9f-4396-8d5f-8c081fb06d67https://git.kernel.org/stable/c/13339132d89d00b513dff0730bff3a313b9b13b5
416baaa9-dc9f-4396-8d5f-8c081fb06d67https://git.kernel.org/stable/c/4a19f7ab5972ef608b31ae921419bc3e04b3f8ad
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": "13339132d89d00b513dff0730bff3a313b9b13b5",
              "status": "affected",
              "version": "e486147c912f653ef4b60a6c7dbd4168a4c56a9f",
              "versionType": "git"
            },
            {
              "lessThan": "4a19f7ab5972ef608b31ae921419bc3e04b3f8ad",
              "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": "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/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\u0027t this predictably trigger the explicit\nassertion BUG_ON((vma-\u003evm_flags \u0026 VM_MIXEDMAP) \u0026\u0026 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."
    }
  ],
  "id": "CVE-2026-74716",
  "lastModified": "2026-08-22T16:16:46.443",
  "metrics": {},
  "published": "2026-08-22T16:16:46.443",
  "references": [
    {
      "source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
      "url": "https://git.kernel.org/stable/c/13339132d89d00b513dff0730bff3a313b9b13b5"
    },
    {
      "source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
      "url": "https://git.kernel.org/stable/c/4a19f7ab5972ef608b31ae921419bc3e04b3f8ad"
    }
  ],
  "sourceIdentifier": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
  "vulnStatus": "Received"
}



Log in or create an account to share your comment.




Tags
Taxonomy of the tags.





Forecast uses a logistic model when the trend is rising, or an exponential decay model when the trend is falling. Fitted via linearized least squares.

Sightings

Author Source Type Date Other

Nomenclature

  • Seen: The vulnerability was mentioned, discussed, or observed by the user.
  • Confirmed: The vulnerability has been validated from an analyst's perspective.
  • Published Proof of Concept: A public proof of concept is available for this vulnerability.
  • Exploited: The vulnerability was observed as exploited by the user who reported the sighting.
  • Patched: The vulnerability was observed as successfully patched by the user who reported the sighting.
  • Not exploited: The vulnerability was not observed as exploited by the user who reported the sighting.
  • Not confirmed: The user expressed doubt about the validity of the vulnerability.
  • Not patched: The vulnerability was not observed as successfully patched by the user who reported the sighting.


Detection rules are retrieved from Rulezet.