drm/xe: skip eviction of a BO with no resource

{
  "id": "4d32658ca13d0f698a22d537639393073ea8f71c1311188f3ad7194121d37865",
  "url": "https://www.cve.org/CVERecord?id=CVE-2026-99209",
  "method": "structured",
  "payload": {
    "kind": "advisory",
    "title": "drm/xe: skip eviction of a BO with no resource",
    "summary": "In the Linux kernel, the following vulnerability has been resolved: drm/xe: skip eviction of a BO with no resource xe_evict_flags() switches on tbo->resource->mem_type to choose an eviction placement. An xe BO can reach eviction with no ttm.resource, e.g. an imported dma-buf BO whose resource was freed during teardown while its attachment is still live: the exporter then invalidates it via xe_dma_buf_move_notify() -> xe_bo_evict(), and the switch dereferences a NULL resource and faults. A BO with no resource has nothing placed or mapped, so there is nothing to evict. Return an empty placement (num_placement = 0), mirroring the handling already used for non-xe scatter-gather BOs just above; ttm_bo_validate() then takes the pipeline-gutting path and returns 0. Without the fix the xe_dma_buf@xe_test_dmabuf_move_notify_no_resource dynamic live selftest will fail with below stack. BUG: kernel NULL pointer dereference, address: 0000000000000010 RIP: 0010:xe_evict_flags+0xf4/0x140 [xe] Call Trace: xe_bo_evict+0x40/0xa0 [xe] ? ttm_bo_pipeline_gutting+0x71/0x180 [ttm] xe_test_dmabuf_move_notify_no_resource+0x182/0x440 [xe] xe_dma_buf_kunit+0x387/0x580 [xe] v2: Add Fixes tag and failure info in commit text (Matt Brost) (cherry picked from commit dbcfaac6331f1fcb0c2fe3ad3e9adb1e5d43ec0c)",
    "evidence": "cve:CVE-2026-99209",
    "products": [
      {
        "name": {
          "value": "Linux",
          "evidence": "/containers/cna/affected/0/product"
        },
        "prerequisites": [],
        "fixed_versions": [],
        "affected_versions": []
      },
      {
        "name": {
          "value": "Linux",
          "evidence": "/containers/cna/affected/1/product"
        },
        "prerequisites": [],
        "fixed_versions": [],
        "affected_versions": []
      }
    ],
    "severity": "unknown",
    "structured": {
      "id": "CVE-2026-99209",
      "aliases": [
        "CVE-2026-99209"
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      "metrics": [],
      "affected": [
        {
          "repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git",
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              "status": "affected",
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          "programFiles": [
            "drivers/gpu/drm/xe/xe_bo.c"
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          "defaultStatus": "unaffected"
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        {
          "repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git",
          "vendor": "Linux",
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          "versions": [
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              "status": "affected",
              "version": "6.8"
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            {
              "status": "unaffected",
              "version": "0",
              "lessThan": "6.8",
              "versionType": "semver"
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              "version": "6.18.59",
              "versionType": "semver",
              "lessThanOrEqual": "6.18.*"
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              "version": "7.2.13",
              "versionType": "semver",
              "lessThanOrEqual": "7.2.*"
            },
            {
              "status": "unaffected",
              "version": "7.3",
              "versionType": "original_commit_for_fix",
              "lessThanOrEqual": "*"
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          ],
          "programFiles": [
            "drivers/gpu/drm/xe/xe_bo.c"
          ],
          "defaultStatus": "affected"
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      ],
      "modified": "2026-10-28T10:36:03.274Z",
      "provider": "cve",
      "references": [
        "https://git.kernel.org/stable/c/6046bb9cb2859e3d9bf939e4d6527f3827e1096f",
        "https://git.kernel.org/stable/c/b6499d19ade1f1e4a1e6b739abc8c815297c98b8",
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      "provider_metadata": {
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          "shortName": "Linux",
          "dateUpdated": "2026-10-28T10:36:03.274Z"
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    "related_cves": [
      {
        "value": "CVE-2026-99209",
        "evidence": "/cveMetadata/cveId"
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    "security_relevant": true,
    "severity_evidence": null
  },
  "source_id": "core-cve",
  "document_id": 425379,
  "published_at": "2026-10-28T10:36:03.274+00:00"
}