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.


Related by attack behaviour

Vulnerabilities whose description is nearest to this one in the vector space of the CIRCL/vulnerability-attack-technique-biencoder model. This is a similarity search over the bi-encoder space (plain cosine), not a classification, and it has no measured accuracy.