{
  "schema_version": "1.6.1",
  "id": "RPI-CVE-2026-80622",
  "modified": "2026-10-09T11:39:44Z",
  "upstream": [
    "CVE-2026-80622"
  ],
  "published": "2026-08-28T06:50:33Z",
  "summary": "char: tlclk: fix use-after-free in tlclk_cleanup()",
  "details": "In the Linux kernel, the following vulnerability has been resolved:\n\nchar: tlclk: fix use-after-free in tlclk_cleanup()\n\nThis patch improves the module cleanup process in the tlclk driver to\nprevent potential use-after-free and race conditions.\n\nCurrently, the file_operations structure does not specify the .owner\nfield, which could allow the module to be unloaded while user-space\nprocesses are still interacting with the device. Additionally, the\ntlclk_cleanup() function frees the alarm_events memory before ensuring\nthat blocked processes in the waitqueue are fully awakened and that the\nswitchover_timer has completed.\n\nTo address these cases, this patch:\n- Sets '.owner = THIS_MODULE' in tlclk_fops to safely defer module\n  unloading while the device is in use.\n- Updates tlclk_cleanup() to explicitly wake up all blocked readers\n  (wake_up_all), properly release hardware I/O regions, and safely\n  delete the timer (timer_delete_sync) prior to freeing memory.",
  "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": "6.1.178",
            "compiled_filter": false
          }
        }
      }
    }
  ],
  "references": [
    {
      "type": "ADVISORY",
      "url": "https://www.cve.org/CVERecord?id=CVE-2026-80622"
    },
    {
      "type": "FIX",
      "url": "https://git.kernel.org/stable/c/09d8d2a46a9ec9ff728f3159a174a2ab25dd0f0a"
    },
    {
      "type": "FIX",
      "url": "https://git.kernel.org/stable/c/96902299a22d126ef5eb3f45cd5d8ceea9e6a735"
    },
    {
      "type": "FIX",
      "url": "https://git.kernel.org/stable/c/166dd1d5265e067459e674c11688919901813ec2"
    },
    {
      "type": "FIX",
      "url": "https://git.kernel.org/stable/c/764723bd67a6c8f53a8d8309211fb039e2ebcf49"
    },
    {
      "type": "FIX",
      "url": "https://git.kernel.org/stable/c/c3f0cd76561ae611c2d247ee96dfd559e4197cb7"
    },
    {
      "type": "FIX",
      "url": "https://git.kernel.org/stable/c/3d5e4cc0d9dce79b0429da3134ac7b072ab9009f"
    },
    {
      "type": "FIX",
      "url": "https://git.kernel.org/stable/c/42223445607a9a5df3cb1c4729abfe3a5085e7ce"
    },
    {
      "type": "FIX",
      "url": "https://git.kernel.org/stable/c/bbf003b7794d6ad6f939fdd29f1f1bde8ac554c1"
    }
  ],
  "database_specific": {
    "source": "https://git.kernel.org/pub/scm/linux/security/vulns.git",
    "upstream_modified": "2026-08-29T06:25:05Z",
    "severity": {
      "source": "kernel CNA",
      "cvss_v3_score": 7.8,
      "cvss_v3_severity": "High",
      "scenario": "AV:L - The UAF is reached only via local open/read syscalls on /dev/telco_clock and tlclk_cleanup() during delete_module/rmmod; this x86 ATCA telecom-clock char driver has no network, Bluetooth, or physical-bus attack surface.\nAC:L - Without .owner the attacker controls both sides of the race by keeping /dev/telco_clock open with read() blocked on wq while IRQs remain active, then timing or piggybacking on module unload to hit kfree(alarm_events) against tlclk_read, tlclk_interrupt, or switchover_timeout.\nPR:L - An unprivileged local user with /dev/telco_clock access can open the device and block in read() while IRQs stay registered; per CNA driver-removal UAF precedent, concurrent admin rmmod triggering tlclk_cleanup() does not require the attacker to hold CAP_SYS_MODULE.\nUI:N - No victim interaction is required; the attacker opens /dev/telco_clock and blocks on read() or sustains IRQ/timer activity themselves while module unload occurs during maintenance or coordinated rmmod, without needing another user to act.\nS:U - Kernel heap UAF during tlclk module cleanup affects only the host kernel on the ATCA blade; this is standard in-kernel memory corruption, not a VM escape, IOMMU bypass, or cross-authority sandbox breakout.\nC:H - tlclk_read() performs copy_to_user from freed alarm_events, and tlclk_interrupt/switchover_timeout dereference the freed buffer; this kernel heap UAF enables arbitrary read primitives via controlled slab reuse and information disclosure.\nI:H - tlclk_read() memset() on freed alarm_events and IRQ/timer handlers increment fields in the freed structure, providing kernel heap write primitives exploitable for control-flow hijack via slab spraying and UAF exploitation.\nA:H - Concurrent access to freed alarm_events from read(), switchover_timeout, or tlclk_interrupt during module unload can cause kernel oops/panic; UAF during driver teardown reliably threatens system availability even when not fully weaponized."
    }
  }
}