CVE-2026-64205

{
  "id": "CVE-2026-64205",
  "sourceIdentifier": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
  "published": "2026-07-20T17:18:22.487",
  "lastModified": "2026-11-06T17:18:40.800",
  "vulnStatus": "Analyzed",
  "cveTags": [],
  "descriptions": [
    {
      "lang": "en",
      "value": "In the Linux kernel, the following vulnerability has been resolved:\n\ni2c: i801: fix hardware state machine corruption in error path\n\nA severe livelock and subsequent Hung Task panic were observed in the\ni2c-i801 driver during concurrent Fuzzing. The crash is caused by an\nunconditional hardware register cleanup in the error handling path of\ni801_access().\n\nWhen i801_check_pre() fails (e.g., returning -EBUSY because the SMBus\ncontroller is actively used by BIOS/ACPI), the kernel does not actually\nacquire the hardware ownership. However, the code jumps to the 'out'\nlabel and executes:\n\n    iowrite8(SMBHSTSTS_INUSE_STS | STATUS_FLAGS, SMBHSTSTS(priv));\n\nThis forcefully clears the INUSE_STS lock and resets the hardware status\nflags without owning the controller. Doing so interrupts ongoing BIOS/ACPI\ntransactions and totally corrupts the SMBus hardware state machine.\n\nConsequently, all subsequent i801_access() calls fail at the pre-check\nstage, triggering an endless stream of \"SMBus is busy, can't use it!\"\nerror logs. Over a slow serial console, this printk flood monopolizes\nthe CPU (Console Livelock), starving other processes trying to acquire\nthe mmap_lock down_read semaphore, ultimately triggering the hung task\nwatchdog.\n\nFix this by moving the 'out' label below the hardware register cleanup.\nIf i801_check_pre() fails, we safely bypass the iowrite8() and only\nrelease the software locks (pm_runtime and mutex), strictly adhering to\nthe rule of not releasing resources that were never acquired."
    }
  ],
  "affected": [
    {
      "source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
      "affectedData": [
        {
          "vendor": "Linux",
          "product": "Linux",
          "defaultStatus": "unaffected",
          "programFiles": [
            "drivers/i2c/busses/i2c-i801.c"
          ],
          "repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git",
          "versions": [
            {
              "version": "1f760b87e54cf56a25ab68f8dc625e339f6e46d5",
              "lessThan": "2ef69871b313aa0f02182795f5e0f5aa455f203c",
              "versionType": "git",
              "status": "affected"
            },
            {
              "version": "1f760b87e54cf56a25ab68f8dc625e339f6e46d5",
              "lessThan": "ef5a347532932f58748dad485c15039f5168c377",
              "versionType": "git",
              "status": "affected"
            },
            {
              "version": "1f760b87e54cf56a25ab68f8dc625e339f6e46d5",
              "lessThan": "bb5133a7d5f3fe5c387770e25f2e00e682ce11ed",
              "versionType": "git",
              "status": "affected"
            },
            {
              "version": "1f760b87e54cf56a25ab68f8dc625e339f6e46d5",
              "lessThan": "00904687b9c5527d569d9a1ca72119823e735a61",
              "versionType": "git",
              "status": "affected"
            },
            {
              "version": "1f760b87e54cf56a25ab68f8dc625e339f6e46d5",
              "lessThan": "10dd1a736d557e310a77117832874729a0175d57",
              "versionType": "git",
              "status": "affected"
            }
          ]
        },
        {
          "vendor": "Linux",
          "product": "Linux",
          "defaultStatus": "affected",
          "programFiles": [
            "drivers/i2c/busses/i2c-i801.c"
          ],
          "repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git",
          "versions": [
            {
              "version": "6.3",
              "status": "affected"
            },
            {
              "version": "0",
              "lessThan": "6.3",
              "versionType": "semver",
              "status": "unaffected"
            },
            {
              "version": "6.6.148",
              "lessThanOrEqual": "6.6.*",
              "versionType": "semver",
              "status": "unaffected"
            },
            {
              "version": "6.12.101",
              "lessThanOrEqual": "6.12.*",
              "versionType": "semver",
              "status": "unaffected"
            },
            {
              "version": "6.18.39",
              "lessThanOrEqual": "6.18.*",
              "versionType": "semver",
              "status": "unaffected"
            },
            {
              "version": "7.1.4",
              "lessThanOrEqual": "7.1.*",
              "versionType": "semver",
              "status": "unaffected"
            },
            {
              "version": "7.2",
              "lessThanOrEqual": "*",
              "versionType": "original_commit_for_fix",
              "status": "unaffected"
            }
          ]
        }
      ]
    }
  ],
  "metrics": {
    "cvssMetricV31": [
      {
        "source": "[email protected]",
        "type": "Primary",
        "cvssData": {
          "version": "3.1",
          "vectorString": "CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:H",
          "baseScore": 5.5,
          "baseSeverity": "MEDIUM",
          "attackVector": "LOCAL",
          "attackComplexity": "LOW",
          "privilegesRequired": "LOW",
          "userInteraction": "NONE",
          "scope": "UNCHANGED",
          "confidentialityImpact": "NONE",
          "integrityImpact": "NONE",
          "availabilityImpact": "HIGH"
        },
        "exploitabilityScore": 1.8,
        "impactScore": 3.6
      }
    ],
    "ssvcV203": [
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        "ssvcData": {
          "timestamp": "2026-11-06T16:32:07.975935Z",
          "id": "CVE-2026-64205",
          "options": [
            {
              "exploitation": "none"
            },
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              "automatable": "no"
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              "technicalImpact": "partial"
            }
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          "role": "CISA Coordinator",
          "version": "2.0.3"
        }
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  },
  "weaknesses": [
    {
      "source": "[email protected]",
      "type": "Primary",
      "description": [
        {
          "lang": "en",
          "value": "NVD-CWE-noinfo"
        }
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      "url": "https://git.kernel.org/stable/c/00904687b9c5527d569d9a1ca72119823e735a61",
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}