Revert "drm/gem-shmem: Use dma_buf from GEM object instance"

{
  "id": "e6caa882966e0811e564cacf7a0716415951ea11d9c8b450a3a622a204e93566",
  "url": "https://osv.dev/vulnerability/CVE-2025-38669",
  "method": "structured",
  "payload": {
    "kind": "advisory",
    "title": "Revert \"drm/gem-shmem: Use dma_buf from GEM object instance\"",
    "summary": "In the Linux kernel, the following vulnerability has been resolved: Revert \"drm/gem-shmem: Use dma_buf from GEM object instance\" This reverts commit 1a148af06000e545e714fe3210af3d77ff903c11. The dma_buf field in struct drm_gem_object is not stable over the object instance's lifetime. The field becomes NULL when user space releases the final GEM handle on the buffer object. This resulted in a NULL-pointer deref. Workarounds in commit 5307dce878d4 (\"drm/gem: Acquire references on GEM handles for framebuffers\") and commit f6bfc9afc751 (\"drm/framebuffer: Acquire internal references on GEM handles\") only solved the problem partially. They especially don't work for buffer objects without a DRM framebuffer associated. Hence, this revert to going back to using .import_attach->dmabuf. v3: - cc stable",
    "evidence": "osv:CVE-2025-38669",
    "products": [
      {
        "name": {
          "value": "Kernel",
          "evidence": "/affected/1/package/name"
        },
        "prerequisites": [],
        "fixed_versions": [
          {
            "value": "6.15.9",
            "evidence": "/affected/1/ranges"
          }
        ],
        "affected_versions": []
      }
    ],
    "severity": "unknown",
    "structured": {
      "id": "CVE-2025-38669",
      "aliases": [
        "CVE-2025-38669"
      ],
      "affected": [
        {
          "ranges": [
            {
              "repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git",
              "type": "GIT",
              "events": [
                {
                  "introduced": "1a148af06000e545e714fe3210af3d77ff903c11"
                },
                {
                  "fixed": "291a77604858a8b47cf6640a12b76e97f99e00ed"
                },
                {
                  "fixed": "6d496e9569983a0d7a05be6661126d0702cf94f7"
                }
              ]
            }
          ],
          "database_specific": {
            "source": "https://storage.googleapis.com/cve-osv-conversion/osv-output/CVE-2025-38669.json"
          }
        },
        {
          "ranges": [
            {
              "type": "ECOSYSTEM",
              "events": [
                {
                  "introduced": "6.15.0"
                },
                {
                  "fixed": "6.15.9"
                }
              ]
            }
          ],
          "package": {
            "name": "Kernel",
            "ecosystem": "Linux"
          },
          "database_specific": {
            "source": "https://storage.googleapis.com/cve-osv-conversion/osv-output/CVE-2025-38669.json"
          }
        }
      ],
      "modified": "2026-10-28T02:30:46.615475368Z",
      "provider": "osv",
      "references": [
        "https://git.kernel.org/stable/c/291a77604858a8b47cf6640a12b76e97f99e00ed",
        "https://git.kernel.org/stable/c/6d496e9569983a0d7a05be6661126d0702cf94f7",
        "https://github.com/CVEProject/cvelistV5/tree/main/cves/2025/38xxx/CVE-2025-38669.json",
        "https://nvd.nist.gov/vuln/detail/CVE-2025-38669",
        "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git"
      ],
      "provider_metadata": {
        "cna_assigner": "Linux",
        "osv_generated_from": "https://github.com/CVEProject/cvelistV5/tree/main/cves/2025/38xxx/CVE-2025-38669.json"
      }
    },
    "related_cves": [
      {
        "value": "CVE-2025-38669",
        "evidence": "/id"
      }
    ],
    "security_relevant": true,
    "severity_evidence": null
  },
  "source_id": "core-osv",
  "document_id": 514485,
  "published_at": "2025-08-22T16:03:00.399+00:00"
}