{
  "schema_version": "1.6.1",
  "id": "RPI-CVE-2026-90025",
  "modified": "2026-10-09T11:39:44Z",
  "upstream": [
    "CVE-2026-90025"
  ],
  "published": "2026-09-16T10:32:03Z",
  "summary": "usb: typec: ucsi: displayport: Fix OOB altmode array index",
  "details": "In the Linux kernel, the following vulnerability has been resolved:\n\nusb: typec: ucsi: displayport: Fix OOB altmode array index\n\nThe UCSI displayport driver indexes the connector's port altmode array\nwith the GET_CURRENT_CAM response after checking it is not 0xff. The\nport altmode array is UCSI_MAX_ALTMODES elements long. If the PPM\nreturns an invalid GET_CURRENT_CAM response above UCSI_MAX_ALTMODES and\nnot equal to 0xff, the kernel may crash with an array index OOB error.\n\nUpdate the UCSI displayport driver to verify the current cam is less\nthan UCSI_MAX_ALTMODES before accessing the port altmode array.",
  "severity": [
    {
      "type": "CVSS_V3",
      "score": "CVSS:3.1/AV:L/AC:L/PR:N/UI:N/S:U/C:H/I:N/A:H"
    }
  ],
  "affected": [
    {
      "package": {
        "ecosystem": "Raspberry Pi OS:12",
        "name": "linux"
      },
      "versions": [
        "1:6.1.47-1+rpt4"
      ],
      "ecosystem_specific": {
        "binaries": [
          {
            "binary_name": "linux-image-6.1.0-rpi3-rpi-2712",
            "binary_version": "1:6.1.47-1+rpt4"
          },
          {
            "binary_name": "linux-image-6.1.0-rpi3-rpi-v6",
            "binary_version": "1:6.1.47-1+rpt4"
          },
          {
            "binary_name": "linux-image-6.1.0-rpi3-rpi-v7",
            "binary_version": "1:6.1.47-1+rpt4"
          },
          {
            "binary_name": "linux-image-6.1.0-rpi3-rpi-v7l",
            "binary_version": "1:6.1.47-1+rpt4"
          },
          {
            "binary_name": "linux-image-6.1.0-rpi3-rpi-v8",
            "binary_version": "1:6.1.47-1+rpt4"
          }
        ]
      },
      "database_specific": {
        "per_version": {
          "1:6.1.47-1+rpt4": {
            "linux_commit": "655fc658a15ae7a6f37103754adb39ba52a9a14e",
            "upstream_version": "6.1.47",
            "assessment": "commit ancestry (strak rule)",
            "upstream_fixed": "6.1.188",
            "compiled_filter": false
          }
        }
      }
    }
  ],
  "references": [
    {
      "type": "ADVISORY",
      "url": "https://www.cve.org/CVERecord?id=CVE-2026-90025"
    },
    {
      "type": "FIX",
      "url": "https://git.kernel.org/stable/c/8fde7e4a366184e9a6aa95541e52933a73c00a74"
    },
    {
      "type": "FIX",
      "url": "https://git.kernel.org/stable/c/83f1abd62cc134700ba92e1e2dc650a49a185497"
    },
    {
      "type": "FIX",
      "url": "https://git.kernel.org/stable/c/1ffed96ef986e2cdf986aa4a4506a5e6dcdf4456"
    },
    {
      "type": "FIX",
      "url": "https://git.kernel.org/stable/c/58e0ee293ec5e06cacbe3953ad44042f1473dae9"
    },
    {
      "type": "FIX",
      "url": "https://git.kernel.org/stable/c/ac9f878c468052af6571e8639ab1c3ae040b908f"
    },
    {
      "type": "FIX",
      "url": "https://git.kernel.org/stable/c/33a81acd2d1d0667d4eff93cb90339fa53e617e8"
    },
    {
      "type": "FIX",
      "url": "https://git.kernel.org/stable/c/bdaaf3074aedce8f1b173cc363d61cff5f6a585f"
    },
    {
      "type": "FIX",
      "url": "https://git.kernel.org/stable/c/04cec690b1fd9d1c4c314b91a10d8c68a3acfe18"
    }
  ],
  "database_specific": {
    "source": "https://git.kernel.org/pub/scm/linux/security/vulns.git",
    "upstream_modified": "2026-09-16T14:40:32Z",
    "severity": {
      "source": "kernel CNA",
      "cvss_v3_score": 7.7,
      "cvss_v3_severity": "High",
      "scenario": "AV:L - The OOB index is the PPM GET_CURRENT_CAM byte from onboard UCSI firmware (ACPI EC, I2C CCG/STM32G0, pmic_glink, Chrome OS EC), not a USB-C partner or network packet. A compromised PPM can report CONNECTED plus DP partner altmodes and drive enter without a physical plug, matching other firmware-to-kernel scores.\nAC:L - The PPM fully controls the GET_CURRENT_CAM u8; any value in 30-254 (UCSI_MAX_ALTMODES is 30, 0xff is the only sentinel) deterministically indexes port_altmode[] out of bounds with no race or attacker-uncontrollable layout.\nPR:N - UCSI connector-change work, GET_CURRENT_CAM, and dp_altmode_probe's automatic enter run in kernel context from PPM notifications with no capable() or credential check, so compromised PPM/EC firmware needs no host account.\nUI:N - Partner registration and DisplayPort altmode enter run automatically from PPM connector-change events and dp_altmode_probe scheduled work; no victim must plug a cable, mount media, or open a device node.\nS:U - The out-of-bounds pointer load stays inside the host kernel UCSI DisplayPort driver and connector heap; it does not cross a VM, IOMMU, or other security-authority boundary.\nC:H - cur is a full u8 used as an index into port_altmode[UCSI_MAX_ALTMODES], so values 30-254 read a kernel pointer from up to about 2KB past the array into adjacent connector/heap memory; that unbounded OOB read scores Confidentiality High.\nI:N - The OOB pointer is only compared to alt to choose 0 versus -EBUSY; it is never written, stored, or used as a write address, so there is no OOB write, use-after-free, or control-flow hijack primitive.\nA:H - An out-of-range CAM can load from unmapped heap, trip KASAN/UBSAN array-index-out-of-bounds, or oops as the fix describes, producing a kernel panic that the PPM can retrigger on each enter."
    }
  }
}