pwrseq: core: fix use-after-free in pwrseq_debugfs_seq_next()

{
  "id": "41ee8eb702e5457bb98dfc533afe30be7c254a7449a88f02285f315ab5c76ba8",
  "url": "https://osv.dev/vulnerability/CVE-2026-64251",
  "method": "structured",
  "payload": {
    "kind": "advisory",
    "title": "pwrseq: core: fix use-after-free in pwrseq_debugfs_seq_next()",
    "summary": "In the Linux kernel, the following vulnerability has been resolved: pwrseq: core: fix use-after-free in pwrseq_debugfs_seq_next() pwrseq_debugfs_seq_next() declares 'next' with __free(put_device), which causes put_device() to be called on the returned pointer when the variable goes out of scope. This results in a use-after-free since the seq_file framework receives a pointer whose reference has already been dropped. Simply removing __free(put_device) would fix the UAF but would leak the reference acquired by bus_find_next_device(), as stop() only calls up_read(&pwrseq_sem) and never releases the device reference. Fix this by making the reference counting consistent across all seq_file callbacks, matching the standard pattern used by PCI and SCSI: - start(): use get_device() so it returns a referenced pointer. - next(): explicitly put_device(curr) to release the previous device's reference (no NULL check needed - the seq_file framework only calls next() while the previous return was non-NULL). - stop(): put_device(data) to release the last iterated device's reference, with a NULL guard since stop() may be called with NULL when start() returned NULL or next() reached end-of-sequence.",
    "evidence": "osv:CVE-2026-64251",
    "products": [
      {
        "name": {
          "value": "Kernel",
          "evidence": "/affected/1/package/name"
        },
        "prerequisites": [],
        "fixed_versions": [
          {
            "value": "6.12.95",
            "evidence": "/affected/1/ranges"
          },
          {
            "value": "6.18.38",
            "evidence": "/affected/1/ranges"
          },
          {
            "value": "7.1.3",
            "evidence": "/affected/1/ranges"
          }
        ],
        "affected_versions": []
      }
    ],
    "severity": "high",
    "structured": {
      "id": "CVE-2026-64251",
      "aliases": [
        "CVE-2026-64251"
      ],
      "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": [
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                  "introduced": "249ebf3f65f8530beb2cbfb91bff1d83ba88d23c"
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                {
                  "fixed": "ba0b9f04c7a5f9887b8ce672eaf049502c0548ec"
                },
                {
                  "fixed": "e91df6d273445c03f5aa302bfe147eda33d45794"
                },
                {
                  "fixed": "73569a44fca2992f0ca4a4c0104069741b9873a0"
                },
                {
                  "fixed": "257595adf9dac15ae1edd9d07753fbc576a7583d"
                }
              ]
            }
          ],
          "database_specific": {
            "source": "https://storage.googleapis.com/cve-osv-conversion/osv-output/CVE-2026-64251.json"
          }
        },
        {
          "ranges": [
            {
              "type": "ECOSYSTEM",
              "events": [
                {
                  "introduced": "6.11.0"
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                {
                  "fixed": "6.12.95"
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            {
              "type": "ECOSYSTEM",
              "events": [
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                  "introduced": "6.13.0"
                },
                {
                  "fixed": "6.18.38"
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              ]
            },
            {
              "type": "ECOSYSTEM",
              "events": [
                {
                  "introduced": "6.19.0"
                },
                {
                  "fixed": "7.1.3"
                }
              ]
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          ],
          "package": {
            "name": "Kernel",
            "ecosystem": "Linux"
          },
          "database_specific": {
            "source": "https://storage.googleapis.com/cve-osv-conversion/osv-output/CVE-2026-64251.json"
          }
        }
      ],
      "modified": "2026-10-28T02:30:51.118149362Z",
      "provider": "osv",
      "references": [
        "https://git.kernel.org/stable/c/257595adf9dac15ae1edd9d07753fbc576a7583d",
        "https://git.kernel.org/stable/c/73569a44fca2992f0ca4a4c0104069741b9873a0",
        "https://git.kernel.org/stable/c/ba0b9f04c7a5f9887b8ce672eaf049502c0548ec",
        "https://git.kernel.org/stable/c/e91df6d273445c03f5aa302bfe147eda33d45794",
        "https://github.com/CVEProject/cvelistV5/tree/main/cves/2026/64xxx/CVE-2026-64251.json",
        "https://nvd.nist.gov/vuln/detail/CVE-2026-64251",
        "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/2026/64xxx/CVE-2026-64251.json"
      }
    },
    "related_cves": [
      {
        "value": "CVE-2026-64251",
        "evidence": "/id"
      }
    ],
    "security_relevant": true,
    "severity_evidence": "/severity/0/score"
  },
  "source_id": "core-osv",
  "document_id": 519600,
  "published_at": "2026-07-24T15:31:17.601+00:00"
}