{
  "cveId": "CVE-2026-97975",
  "url": "https://patchblox.com/security/cve/CVE-2026-97975",
  "summary": "CVE-2026-97975 is fixed in linux on 1 platform, first by DEBIAN-CVE-2026-97975, released October 2, 2026. It is not reported as exploited. Patch Radar priority: Routine.",
  "title": "Bluetooth: hci_sysfs: Fix NULL pointer dereference in device_del()",
  "description": "In the Linux kernel, the following vulnerability has been resolved:  Bluetooth: hci_sysfs: Fix NULL pointer dereference in device_del()  A NULL pointer dereference in klist_put() occurs when a child device (such as a BNEP network device in bnep_session) is concurrently being unregistered while hci_conn_del_sysfs() reparents child devices.  This is caused by a race condition between hci_conn_del_sysfs() and concurrent child device unregistration (e.g. bnep_session calling unregister_netdev()). During device unregistration, device_del() snapshots a non-NULL parent pointer. Concurrently, hci_conn_del_sysfs() finds the child device using device_find_any_child() and calls device_move() to reparent it to NULL, which removes the node from its parent\u0027s klist and clears knode_parent. Subsequently, device_del() calls klist_del(\u0026dev-\u003Ep-\u003Eknode_parent) using the stale parent snapshot, causing klist_put() to dereference knode_klist(n)-\u003Eput on an already removed node, resulting in a NULL pointer dereference.  This race was introduced by commit 27aabf27fd01 (\u0022Bluetooth: fix use-after-free in device_for_each_child()\u0022), which replaced device_find_child(..., __match_tty) with device_find_any_child() in hci_conn_del_sysfs(). That change was intended to avoid a use-after-free where conn-\u003Edev outlived its parent hdev-\u003Edev when child devices held references to conn-\u003Edev, because conn-\u003Edev only held a reference to hdev-\u003Edev while registered in sysfs.  Fix the issue properly by taking an explicit reference to the parent device with get_device(\u0026hdev-\u003Edev) in hci_conn_init_sysfs() and dropping it with put_device(parent) in bt_link_release() when the conn device is freed. This ensures that hdev-\u003Edev remains valid for the entire lifecycle of conn-\u003Edev, resolving the underlying use-after-free. With the parent reference held properly, restore the __match_tty filter in hci_conn_del_sysfs() so that device_move() is only invoked on persistent RFCOMM TTY devices as originally intended, eliminating the race condition with unregistering network devices.",
  "published": "2026-09-25T11:17:25Z",
  "severity": "Moderate",
  "cvss": 4.7,
  "epss": 0.00168,
  "epssPercentile": 0.0618,
  "priority": "Routine",
  "priorityTier": 4,
  "exploited": false,
  "vendorExploited": false,
  "disclosed": false,
  "vendorAdvisory": "https://msrc.microsoft.com/update-guide/vulnerability/CVE-2026-97975",
  "fixes": [
    {
      "platform": "linux",
      "product": "linux",
      "release": "Debian 13.5 (trixie)",
      "fixedVersion": "6.12.115-2",
      "fix": "DEBIAN-CVE-2026-97975",
      "url": "https://patchblox.com/security/fix/linux/debian-cve-2026-97975",
      "released": "2026-10-02T21:04:56Z"
    },
    {
      "platform": "linux",
      "product": "linux",
      "release": "Debian 14",
      "fixedVersion": "7.2.7-1",
      "fix": "DEBIAN-CVE-2026-97975",
      "url": "https://patchblox.com/security/fix/linux/debian-cve-2026-97975",
      "released": "2026-10-02T21:04:56Z"
    }
  ],
  "noFixYet": [],
  "dataAsOf": "2026-11-09T01:18:40Z",
  "attribution": {
    "text": "Data: Patchblox Patch Radar",
    "url": "https://patchblox.com/security/patch-radar",
    "terms": "https://patchblox.com/security/patch-radar/use-the-data"
  }
}