drm/xe/guc: Fix buffer overflow in steered register list allocation

{
  "id": "16eee263a9835af69b461dd09b28e8523f9af3544d980f1b7504623d15447d43",
  "url": "https://osv.dev/vulnerability/CVE-2026-68274",
  "method": "structured",
  "payload": {
    "kind": "advisory",
    "title": "drm/xe/guc: Fix buffer overflow in steered register list allocation",
    "summary": "In the Linux kernel, the following vulnerability has been resolved: drm/xe/guc: Fix buffer overflow in steered register list allocation The size calculation for the steered register extarray uses only the geometry DSS mask (g_dss_mask) to determine the number of entries to allocate: total = bitmap_weight(gt->fuse_topo.g_dss_mask, ...) * steer_reg_num; However, the filling loop uses for_each_dss_steering(), which iterates over for_each_dss(), defined as the union of g_dss_mask and c_dss_mask (geometry + compute DSS). On platforms with compute-only DSS bits, the loop writes past the allocated buffer, corrupting adjacent slab objects. This manifests as list_del corruption and SLUB redzone overwrites during drm_managed_release on device unbind, since the overflow corrupts the drmres list_head of neighboring allocations. Fix by computing the allocation size using the union of both DSS masks, matching the iteration pattern of for_each_dss_steering(). -- v2: - use bitmap_weighted_or() (Zhanjun) (cherry picked from commit 0a78a44f4901aa6c9263e66be7fce02282f1109f)",
    "evidence": "osv:CVE-2026-68274",
    "products": [
      {
        "name": {
          "value": "Kernel",
          "evidence": "/affected/1/package/name"
        },
        "prerequisites": [],
        "fixed_versions": [
          {
            "value": "6.18.44",
            "evidence": "/affected/1/ranges"
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          {
            "value": "7.1.6",
            "evidence": "/affected/1/ranges"
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    "severity": "high",
    "structured": {
      "id": "CVE-2026-68274",
      "aliases": [
        "CVE-2026-68274"
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      "metrics": [
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          "type": "CVSS_V3",
          "score": "CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H"
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          "ranges": [
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              "type": "ECOSYSTEM",
              "events": [
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                  "introduced": "6.13.0"
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                  "fixed": "6.18.44"
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            {
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            "ecosystem": "Linux"
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            "source": "https://storage.googleapis.com/cve-osv-conversion/osv-output/CVE-2026-68274.json"
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      "modified": "2026-10-28T02:30:34.443295286Z",
      "provider": "osv",
      "references": [
        "https://git.kernel.org/stable/c/632ecc90e1ca5d3b6822bb4d08f84a175b6c42c0",
        "https://git.kernel.org/stable/c/a9a020f3c11eba6573b699f9cf9245a51b025ade",
        "https://git.kernel.org/stable/c/b485bfb45555163bfa5f565d6a3415fcb3035b02",
        "https://github.com/CVEProject/cvelistV5/tree/main/cves/2026/68xxx/CVE-2026-68274.json",
        "https://nvd.nist.gov/vuln/detail/CVE-2026-68274",
        "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-2026-68274.json"
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        "value": "CVE-2026-68274",
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    "severity_evidence": "/severity/0/score"
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  "source_id": "core-osv",
  "document_id": 501986,
  "published_at": "2026-08-10T12:01:49.762+00:00"
}