{
  "schemaVersion": 1,
  "attribution": [
    {
      "source": "CISA Known Exploited Vulnerabilities",
      "url": "https://www.cisa.gov/known-exploited-vulnerabilities-catalog",
      "licence": "US government work"
    },
    {
      "source": "GitHub Advisory Database",
      "url": "https://github.com/advisories",
      "licence": "CC BY 4.0"
    },
    {
      "source": "Have I Been Pwned",
      "url": "https://haveibeenpwned.com/",
      "licence": "CC BY 4.0"
    },
    {
      "source": "CVE Program (CVE records)",
      "url": "https://www.cve.org/Legal/TermsOfUse",
      "licence": "CVE Terms of Use",
      "notice": "Copyright © 1999-2026, The MITRE Corporation. CVE is a trademark and the CVE logo is a registered trademark of The MITRE Corporation.",
      "terms": "CVE Usage: MITRE hereby grants you a perpetual, worldwide, non-exclusive, no-charge, royalty-free, irrevocable copyright license to reproduce, prepare derivative works of, publicly display, publicly perform, sublicense, and distribute Common Vulnerabilities and Exposures (CVE™). Any copy you make for such purposes is authorized provided that you reproduce MITRE's copyright designation and this license in any such copy."
    },
    {
      "source": "FIRST EPSS",
      "url": "https://www.first.org/epss/",
      "licence": "free to use; FIRST requests attribution"
    }
  ],
  "record": {
    "id": "CVE-2025-21902",
    "sourceURL": "https://www.cve.org/CVERecord?id=CVE-2025-21902",
    "idYear": 2025,
    "status": "PUBLISHED",
    "publishedAt": "2025-04-01T15:40:44.425Z",
    "updatedAt": "2026-05-23T15:57:24.856Z",
    "importedAt": "2026-10-24T01:57:29.455Z",
    "snapshot": {
      "id": "cve_2026-10-24_midnight_baseline",
      "at": "2026-10-24T00:00:00.000Z",
      "source": "https://github.com/CVEProject/cvelistV5/releases/tag/cve_2026-10-24_0100Z"
    },
    "facts": {
      "title": "acpi: typec: ucsi: Introduce a ->poll_cci method",
      "summary": "In the Linux kernel, the following vulnerability has been resolved:\n\nacpi: typec: ucsi: Introduce a ->poll_cci method\n\nFor the ACPI backend of UCSI the UCSI \"registers\" are just a memory copy\nof the register values in an opregion. The ACPI implementation in the\nBIOS ensures that the opregion contents are synced to the embedded\ncontroller and it ensures that the registers (in particular CCI) are\nsynced back to the opregion on notifications. While there is an ACPI call\nthat syncs the actual registers to the opregion there is rarely a need to\ndo this and on some ACPI implementations it actually breaks in various\ninteresting ways.\n\nThe only reason to force a sync from the embedded controller is to poll\nCCI while notifications are disabled. Only the ucsi core knows if this\nis the case and guessing based on the current command is suboptimal, i.e.\nleading to the following spurious assertion splat:\n\nWARNING: CPU: 3 PID: 76 at drivers/usb/typec/ucsi/ucsi.c:1388 ucsi_reset_ppm+0x1b4/0x1c0 [typec_ucsi]\nCPU: 3 UID: 0 PID: 76 Comm: kworker/3:0 Not tainted 6.12.11-200.fc41.x86_64 #1\nHardware name: LENOVO 21D0/LNVNB161216, BIOS J6CN45WW 03/17/2023\nWorkqueue: events_long ucsi_init_work [typec_ucsi]\nRIP: 0010:ucsi_reset_ppm+0x1b4/0x1c0 [typec_ucsi]\nCall Trace:\n <TASK>\n ucsi_init_work+0x3c/0xac0 [typec_ucsi]\n process_one_work+0x179/0x330\n worker_thread+0x252/0x390\n kthread+0xd2/0x100\n ret_from_fork+0x34/0x50\n ret_from_fork_asm+0x1a/0x30\n </TASK>\n\nThus introduce a ->poll_cci() method that works like ->read_cci() with an\nadditional forced sync and document that this should be used when polling\nwith notifications disabled. For all other backends that presumably don't\nhave this issue use the same implementation for both methods.",
      "affected": [
        {
          "vendor": "Linux",
          "product": "Linux",
          "defaultStatus": "unaffected",
          "versions": [
            {
              "version": "c0ca6fd5f6ebde8fc0df8bb5c32629d1284f60d0",
              "status": "affected",
              "versionType": "git",
              "lessThan": "012b98cdb54c7d47743ee7fc402fa23f2d90529a"
            },
            {
              "version": "fa48d7e81624efdf398b990a9049e9cd75a5aead",
              "status": "affected",
              "versionType": "git",
              "lessThan": "1aec5c9066965ac0984e385bbc31455ae31cbffc"
            },
            {
              "version": "fa48d7e81624efdf398b990a9049e9cd75a5aead",
              "status": "affected",
              "versionType": "git",
              "lessThan": "976e7e9bdc7719a023a4ecccd2e3daec9ab20a40"
            },
            {
              "version": "6.12.5",
              "status": "affected",
              "versionType": "semver",
              "lessThan": "6.12.19"
            }
          ]
        },
        {
          "vendor": "Linux",
          "product": "Linux",
          "defaultStatus": "affected",
          "versions": [
            {
              "version": "6.13",
              "status": "affected"
            },
            {
              "version": "0",
              "status": "unaffected",
              "versionType": "semver",
              "lessThan": "6.13"
            },
            {
              "version": "6.12.19",
              "status": "unaffected",
              "versionType": "semver",
              "lessThanOrEqual": "6.12.*"
            },
            {
              "version": "6.13.7",
              "status": "unaffected",
              "versionType": "semver",
              "lessThanOrEqual": "6.13.*"
            },
            {
              "version": "6.14",
              "status": "unaffected",
              "versionType": "original_commit_for_fix",
              "lessThanOrEqual": "*"
            }
          ]
        }
      ]
    }
  }
}