{
  "schema_version": "1.6.1",
  "id": "RPI-CVE-2026-80572",
  "modified": "2026-10-09T11:39:44Z",
  "upstream": [
    "CVE-2026-80572"
  ],
  "published": "2026-08-26T14:37:59Z",
  "summary": "Input: byd - synchronize timer deletion before freeing private data",
  "details": "In the Linux kernel, the following vulnerability has been resolved:\n\nInput: byd - synchronize timer deletion before freeing private data\n\nbyd_disconnect() uses timer_delete() before freeing the driver's private\ndata.  This does not wait for a running byd_clear_touch() callback, which\ndereferences the private data and its psmouse pointer.  A callback racing\nwith disconnect can therefore access the private data after it has been\nfreed.  The timer can also still be re-armed by byd_process_byte() while\nthe disconnect is in progress.\n\nUse timer_shutdown_sync() before freeing the private data: it waits for\na running callback and turns any later re-arm attempt into a no-op.",
  "severity": [
    {
      "type": "CVSS_V3",
      "score": "CVSS:3.1/AV:L/AC:L/PR:L/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": "6.1.185",
            "compiled_filter": false
          }
        }
      }
    }
  ],
  "references": [
    {
      "type": "ADVISORY",
      "url": "https://www.cve.org/CVERecord?id=CVE-2026-80572"
    },
    {
      "type": "FIX",
      "url": "https://git.kernel.org/stable/c/84b205297fa15f97510342221d8c9a0119711478"
    },
    {
      "type": "FIX",
      "url": "https://git.kernel.org/stable/c/28d984a66b9e14be74986167b6ad40b5e0daf19a"
    },
    {
      "type": "FIX",
      "url": "https://git.kernel.org/stable/c/ee944a706a18322b4a2599eebe8040a2994e928f"
    },
    {
      "type": "FIX",
      "url": "https://git.kernel.org/stable/c/8dbfd8e32a13e116790780ed0be82b5a05eb9916"
    },
    {
      "type": "FIX",
      "url": "https://git.kernel.org/stable/c/2e509ef60ee41a2da0deb062c262bb530143fb37"
    },
    {
      "type": "FIX",
      "url": "https://git.kernel.org/stable/c/c83e79c0842ed29860648bcce5022ef0ba5001c6"
    }
  ],
  "database_specific": {
    "source": "https://git.kernel.org/pub/scm/linux/security/vulns.git",
    "upstream_modified": "2026-08-27T12:40:42Z",
    "severity": {
      "source": "kernel CNA",
      "cvss_v3_score": 7.8,
      "cvss_v3_severity": "High",
      "scenario": "AV:L - Reachable from local PS/2 input: BYD packets enter via serio_interrupt() from built-in touchpad hardware or userio-emulated SERIO_8042 port; byd_process_byte()/byd_disconnect() are not network-exposed.\nAC:L - An attacker can arm the 64ms byd_clear_touch timer via touch/relative packets while concurrently closing userio or unbinding the port to invoke byd_disconnect(), controlling both sides of the disconnect/timer race.\nPR:L - Exploitation needs only local access to the PS/2 touchpad or /dev/userio to inject packets and trigger teardown; no init-namespace root, CAP_SYS_ADMIN, or write access to psmouse sysfs is required.\nUI:N - The attacker supplies touchpad traffic and drives device disconnect/emulation teardown themselves; no separate victim interaction (mount, plug-in approval, or click) is needed.\nS:U - Corruption stays within the host kernel address space during PS/2 driver teardown; it is standard local privilege escalation, not a guest-to-host or sandbox boundary crossing.\nC:H - byd_clear_touch() dereferences freed byd_data (priv->psmouse) and can read attacker-reclaimed slab contents, enabling kernel pointer disclosure and broader arbitrary read primitives typical of heap use-after-free bugs.\nI:H - The timer callback writes into freed byd_data fields and may call input/report helpers through a stale psmouse pointer, giving heap corruption and a path to arbitrary kernel writes or control-flow hijacking.\nA:H - Racing the timer with disconnect can cause invalid pointer dereferences, use-after-free access, kernel oops, or panic during input teardown; the condition is repeatable by re-arming the timer."
    }
  }
}