i2c: i801: fix hardware state machine corruption in error path

{
  "id": "c938ba0a35236d8bc8d737f675e8bd6a478b8bb9c0eb29dbfdd53d33497dc7a2",
  "url": "https://osv.dev/vulnerability/CVE-2026-64205",
  "method": "structured",
  "payload": {
    "kind": "advisory",
    "title": "i2c: i801: fix hardware state machine corruption in error path",
    "summary": "In the Linux kernel, the following vulnerability has been resolved: i2c: i801: fix hardware state machine corruption in error path A severe livelock and subsequent Hung Task panic were observed in the i2c-i801 driver during concurrent Fuzzing. The crash is caused by an unconditional hardware register cleanup in the error handling path of i801_access(). When i801_check_pre() fails (e.g., returning -EBUSY because the SMBus controller is actively used by BIOS/ACPI), the kernel does not actually acquire the hardware ownership. However, the code jumps to the 'out' label and executes: iowrite8(SMBHSTSTS_INUSE_STS | STATUS_FLAGS, SMBHSTSTS(priv)); This forcefully clears the INUSE_STS lock and resets the hardware status flags without owning the controller. Doing so interrupts ongoing BIOS/ACPI transactions and totally corrupts the SMBus hardware state machine. Consequently, all subsequent i801_access() calls fail at the pre-check stage, triggering an endless stream of \"SMBus is busy, can't use it!\" error logs. Over a slow serial console, this printk flood monopolizes the CPU (Console Livelock), starving other processes trying to acquire the mmap_lock down_read semaphore, ultimately triggering the hung task watchdog. Fix this by moving the 'out' label below the hardware register cleanup. If i801_check_pre() fails, we safely bypass the iowrite8() and only release the software locks (pm_runtime and mutex), strictly adhering to the rule of not releasing resources that were never acquired",
    "evidence": "osv:CVE-2026-64205",
    "products": [
      {
        "name": {
          "value": "Kernel",
          "evidence": "/affected/1/package/name"
        },
        "prerequisites": [],
        "fixed_versions": [
          {
            "value": "6.6.148",
            "evidence": "/affected/1/ranges"
          },
          {
            "value": "6.12.101",
            "evidence": "/affected/1/ranges"
          },
          {
            "value": "6.18.39",
            "evidence": "/affected/1/ranges"
          },
          {
            "value": "7.1.4",
            "evidence": "/affected/1/ranges"
          }
        ],
        "affected_versions": []
      }
    ],
    "severity": "unknown",
    "structured": {
      "id": "CVE-2026-64205",
      "aliases": [
        "CVE-2026-64205"
      ],
      "affected": [
        {
          "ranges": [
            {
              "repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git",
              "type": "GIT",
              "events": [
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                  "introduced": "1f760b87e54cf56a25ab68f8dc625e339f6e46d5"
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                {
                  "fixed": "2ef69871b313aa0f02182795f5e0f5aa455f203c"
                },
                {
                  "fixed": "ef5a347532932f58748dad485c15039f5168c377"
                },
                {
                  "fixed": "bb5133a7d5f3fe5c387770e25f2e00e682ce11ed"
                },
                {
                  "fixed": "00904687b9c5527d569d9a1ca72119823e735a61"
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                {
                  "fixed": "10dd1a736d557e310a77117832874729a0175d57"
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          "database_specific": {
            "source": "https://storage.googleapis.com/cve-osv-conversion/osv-output/CVE-2026-64205.json"
          }
        },
        {
          "ranges": [
            {
              "type": "ECOSYSTEM",
              "events": [
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                  "introduced": "6.3.0"
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                {
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            {
              "type": "ECOSYSTEM",
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                  "introduced": "6.7.0"
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              "type": "ECOSYSTEM",
              "events": [
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                  "introduced": "6.13.0"
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                {
                  "fixed": "6.18.39"
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            {
              "type": "ECOSYSTEM",
              "events": [
                {
                  "introduced": "6.19.0"
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                {
                  "fixed": "7.1.4"
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              ]
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          ],
          "package": {
            "name": "Kernel",
            "ecosystem": "Linux"
          },
          "database_specific": {
            "source": "https://storage.googleapis.com/cve-osv-conversion/osv-output/CVE-2026-64205.json"
          }
        }
      ],
      "modified": "2026-10-28T02:30:43.589590692Z",
      "provider": "osv",
      "references": [
        "https://git.kernel.org/stable/c/00904687b9c5527d569d9a1ca72119823e735a61",
        "https://git.kernel.org/stable/c/10dd1a736d557e310a77117832874729a0175d57",
        "https://git.kernel.org/stable/c/2ef69871b313aa0f02182795f5e0f5aa455f203c",
        "https://git.kernel.org/stable/c/bb5133a7d5f3fe5c387770e25f2e00e682ce11ed",
        "https://git.kernel.org/stable/c/ef5a347532932f58748dad485c15039f5168c377",
        "https://github.com/CVEProject/cvelistV5/tree/main/cves/2026/64xxx/CVE-2026-64205.json",
        "https://nvd.nist.gov/vuln/detail/CVE-2026-64205",
        "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-2026-64205.json"
      }
    },
    "related_cves": [
      {
        "value": "CVE-2026-64205",
        "evidence": "/id"
      }
    ],
    "security_relevant": true,
    "severity_evidence": null
  },
  "source_id": "core-osv",
  "document_id": 511550,
  "published_at": "2026-07-20T16:27:53.31+00:00"
}