drm/xe: Hold a dma-buf reference for imported BOs

{
  "id": "17d2d779d2b15341f24db2ed77322b8a650621201e6c6e6c37afb40c8d3a669e",
  "url": "https://osv.dev/vulnerability/CVE-2026-68266",
  "method": "structured",
  "payload": {
    "kind": "advisory",
    "title": "drm/xe: Hold a dma-buf reference for imported BOs",
    "summary": "In the Linux kernel, the following vulnerability has been resolved: drm/xe: Hold a dma-buf reference for imported BOs An imported dma-buf BO is created as a ttm_bo_type_sg BO whose reservation object is the exporter's dma_buf->resv. The importer, however, only takes a dma-buf reference after a successful dma_buf_dynamic_attach(). Until then nothing keeps the exporter alive, so if the exporter is freed while the BO still references its resv, a later access to that resv is a use-after-free: Oops: general protection fault, probably for non-canonical address 0x6b6b6b6b6b6b6b9c Workqueue: ttm ttm_bo_delayed_delete [ttm] RIP: 0010:mutex_can_spin_on_owner+0x3f/0xc0 This can be reached on two paths: - dma_buf_dynamic_attach() fails, or - ttm_bo_init_reserved() fails during BO creation. In both cases the BO already has bo->base.resv pointing at the exporter resv, and sg BOs are always torn down via ttm_bo_delayed_delete(), which locks bo->base.resv asynchronously - potentially after the exporter has been freed. Take the dma-buf reference in xe_bo_init_locked(), before ttm_bo_init_reserved(), so it also covers a creation failure there, and release it in xe_ttm_bo_destroy(). The reference is held for the whole BO lifetime, keeping the shared resv alive on every path. v2: - Reworked the fix to avoid creating the imported sg BO before dma_buf_dynamic_attach() succeeds. - Attach with importer_priv == NULL and make invalidate_mappings ignore incomplete imports. v3: - Dropped the xe-side reo",
    "evidence": "osv:CVE-2026-68266",
    "products": [
      {
        "name": {
          "value": "Kernel",
          "evidence": "/affected/1/package/name"
        },
        "prerequisites": [],
        "fixed_versions": [
          {
            "value": "6.12.103",
            "evidence": "/affected/1/ranges"
          },
          {
            "value": "6.18.42",
            "evidence": "/affected/1/ranges"
          },
          {
            "value": "7.1.6",
            "evidence": "/affected/1/ranges"
          }
        ],
        "affected_versions": []
      }
    ],
    "severity": "high",
    "structured": {
      "id": "CVE-2026-68266",
      "aliases": [
        "CVE-2026-68266"
      ],
      "metrics": [
        {
          "type": "CVSS_V3",
          "score": "CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H"
        }
      ],
      "affected": [
        {
          "ranges": [
            {
              "repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git",
              "type": "GIT",
              "events": [
                {
                  "introduced": "dd08ebf6c3525a7ea2186e636df064ea47281987"
                },
                {
                  "fixed": "c22d65d62b3318e237c0e5b1177d90ab83d9fe06"
                },
                {
                  "fixed": "c1954c66662de477a8f4309335b775f7b07bd28b"
                },
                {
                  "fixed": "ba8c4cbb31c6f81fa5b12d6e28f1f706040aff48"
                },
                {
                  "fixed": "62775525a27c3b0d56382e08ba81ee2d322058b6"
                }
              ]
            }
          ],
          "database_specific": {
            "source": "https://storage.googleapis.com/cve-osv-conversion/osv-output/CVE-2026-68266.json"
          }
        },
        {
          "ranges": [
            {
              "type": "ECOSYSTEM",
              "events": [
                {
                  "introduced": "6.8.0"
                },
                {
                  "fixed": "6.12.103"
                }
              ]
            },
            {
              "type": "ECOSYSTEM",
              "events": [
                {
                  "introduced": "6.13.0"
                },
                {
                  "fixed": "6.18.42"
                }
              ]
            },
            {
              "type": "ECOSYSTEM",
              "events": [
                {
                  "introduced": "6.19.0"
                },
                {
                  "fixed": "7.1.6"
                }
              ]
            }
          ],
          "package": {
            "name": "Kernel",
            "ecosystem": "Linux"
          },
          "database_specific": {
            "source": "https://storage.googleapis.com/cve-osv-conversion/osv-output/CVE-2026-68266.json"
          }
        }
      ],
      "modified": "2026-10-28T02:30:23.412584160Z",
      "provider": "osv",
      "references": [
        "https://git.kernel.org/stable/c/62775525a27c3b0d56382e08ba81ee2d322058b6",
        "https://git.kernel.org/stable/c/ba8c4cbb31c6f81fa5b12d6e28f1f706040aff48",
        "https://git.kernel.org/stable/c/c1954c66662de477a8f4309335b775f7b07bd28b",
        "https://git.kernel.org/stable/c/c22d65d62b3318e237c0e5b1177d90ab83d9fe06",
        "https://github.com/CVEProject/cvelistV5/tree/main/cves/2026/68xxx/CVE-2026-68266.json",
        "https://nvd.nist.gov/vuln/detail/CVE-2026-68266",
        "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/2026/68xxx/CVE-2026-68266.json"
      }
    },
    "related_cves": [
      {
        "value": "CVE-2026-68266",
        "evidence": "/id"
      }
    ],
    "security_relevant": true,
    "severity_evidence": "/severity/0/score"
  },
  "source_id": "core-osv",
  "document_id": 490130,
  "published_at": "2026-08-10T12:01:41.28+00:00"
}