drm/sched: Fix fence reference count leak

{
  "id": "c749afbf9b09701ae8554d09e1902e60ed45e9fa80e5007fedad6925d7aabd36",
  "url": "https://osv.dev/vulnerability/CVE-2025-21995",
  "method": "structured",
  "payload": {
    "kind": "advisory",
    "title": "drm/sched: Fix fence reference count leak",
    "summary": "In the Linux kernel, the following vulnerability has been resolved: drm/sched: Fix fence reference count leak The last_scheduled fence leaks when an entity is being killed and adding the cleanup callback fails. Decrement the reference count of prev when dma_fence_add_callback() fails, ensuring proper balance. [phasta: add git tag info for stable kernel]",
    "evidence": "osv:CVE-2025-21995",
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    "severity": "medium",
    "structured": {
      "id": "CVE-2025-21995",
      "aliases": [
        "CVE-2025-21995"
      ],
      "metrics": [
        {
          "type": "CVSS_V3",
          "score": "CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:H"
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      "modified": "2026-10-28T02:30:43.189628551Z",
      "provider": "osv",
      "references": [
        "https://git.kernel.org/stable/c/1135a9431160575466ea9ac37ebd756ecbe35fff",
        "https://git.kernel.org/stable/c/35399c84dcedd6d31448fb9e1336ef52673f2882",
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        "https://github.com/CVEProject/cvelistV5/tree/main/cves/2025/21xxx/CVE-2025-21995.json",
        "https://nvd.nist.gov/vuln/detail/CVE-2025-21995",
        "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/2025/21xxx/CVE-2025-21995.json"
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    },
    "related_cves": [
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    "security_relevant": true,
    "severity_evidence": "/severity/0/score"
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  "source_id": "core-osv",
  "document_id": 510711,
  "published_at": "2025-04-03T07:18:59.178+00:00"
}