{
  "schema_version": "1.6.1",
  "id": "RPI-CVE-2026-80574",
  "modified": "2026-10-09T11:39:44Z",
  "upstream": [
    "CVE-2026-80574"
  ],
  "published": "2026-08-26T14:37:59Z",
  "summary": "Input: focaltech - fix array out-of-bounds in focaltech_process_rel_packet",
  "details": "In the Linux kernel, the following vulnerability has been resolved:\n\nInput: focaltech - fix array out-of-bounds in focaltech_process_rel_packet\n\nMake finger2 (and also finger1) unsigned, so that if the finger index in\nthe packet is 0 then subtracting 1 creates an array index which overflows\nabove the existing check for FOC_MAX_FINGERS, as the existing comment says\nit should, instead of writing to state->fingers[-1].",
  "severity": [
    {
      "type": "CVSS_V3",
      "score": "CVSS:3.1/AV:L/AC:L/PR:N/UI:N/S:U/C:H/I:H/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": "6.1.184",
            "compiled_filter": false
          }
        }
      }
    }
  ],
  "references": [
    {
      "type": "ADVISORY",
      "url": "https://www.cve.org/CVERecord?id=CVE-2026-80574"
    },
    {
      "type": "FIX",
      "url": "https://git.kernel.org/stable/c/063b4c6a6f3fc01bca085c442000c9c100fdbd93"
    },
    {
      "type": "FIX",
      "url": "https://git.kernel.org/stable/c/bb502d79acb9ac1e0a77fa8bc7b7b4729140b11f"
    },
    {
      "type": "FIX",
      "url": "https://git.kernel.org/stable/c/ca92c98b806839c108995b2bbff7061515bdfb53"
    },
    {
      "type": "FIX",
      "url": "https://git.kernel.org/stable/c/81b07470cb2937ceb74b00be88151582a322433b"
    },
    {
      "type": "FIX",
      "url": "https://git.kernel.org/stable/c/6f6d5fe29efdf5001bc146fc292e6592cace93eb"
    },
    {
      "type": "FIX",
      "url": "https://git.kernel.org/stable/c/83c265bfc084d77e2171d4b67362150ab38c935b"
    },
    {
      "type": "FIX",
      "url": "https://git.kernel.org/stable/c/1842e47126816e56d30c4f856f9854fd7831066c"
    },
    {
      "type": "FIX",
      "url": "https://git.kernel.org/stable/c/296736076b3fd078742651c719555a488624023a"
    }
  ],
  "database_specific": {
    "source": "https://git.kernel.org/pub/scm/linux/security/vulns.git",
    "upstream_modified": "2026-08-27T05:18:36Z",
    "severity": {
      "source": "kernel CNA",
      "cvss_v3_score": 8.4,
      "cvss_v3_severity": "High",
      "scenario": "AV:L - FocalTech FOC_REL packets reach focaltech_process_rel_packet through i8042/serio hardware interrupts, ps2_interrupt, psmouse_receive_byte, and focaltech_process_byte with no syscall gate; any local user on a laptop with an integrated FocalTech PS/2 touchpad can deliver the triggering bytes by normal touchpad use.\nAC:L - When the second relative finger index is 0, a documented valid case for odd finger counts, signed underflow makes finger2 -1 pass the FOC_MAX_FINGERS bound test and causes a reliable out-of-bounds write on every such packet without races or attacker-uncontrollable memory layout.\nPR:N - No Linux account, capability, or namespace privilege is required; the integrated touchpad feeds bytes directly into the kernel interrupt handler during normal operation, including at the login screen before authentication.\nUI:N - An attacker with brief local access can trigger the corrupting multitouch gestures directly on the touchpad; exploitation does not depend on a separate victim performing an unusual action beyond touching the device.\nS:U - The vulnerability corrupts kmalloc-allocated focaltech_data within the host kernel psmouse driver; impact is standard in-kernel memory corruption rather than crossing a guest/host, VM, or IOMMU security boundary.\nC:H - Out-of-bounds += writes to fingers[-1].x and fingers[-1].y corrupt adjacent focaltech_data fields such as y_max in kernel heap memory; this class of heap corruption can be leveraged for kernel information disclosure.\nI:H - Attacker-influenced PS/2 packet bytes supply signed 8-bit deltas that repeatedly perform out-of-bounds writes immediately before fingers[0], enabling progressive corruption of neighboring driver state and potential privilege escalation.\nA:H - Corrupting kmalloc-allocated driver state via fingers[-1] can destabilize the input subsystem or adjacent heap objects, causing kernel oops, panic, or repeatable denial of service on affected laptops."
    }
  }
}