---
id: CVE-2026-97975
title: |-
  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 …
summary: |-
  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 …
severity: none
vendor: Linux
product: Linux
affected:
  - >-
    Linux >= 27aabf27fd014ae037cc179c61b0bee7cff55b3d <
    eeabdb25c3209569367e99a85ca9a503b64a646d
  - >-
    Linux >= 27aabf27fd014ae037cc179c61b0bee7cff55b3d <
    9e9ece97b8e716890793de261574b8efef7d8702
  - >-
    Linux >= 27aabf27fd014ae037cc179c61b0bee7cff55b3d <
    9b851b09b392da68bd715601f10a5adb2d8d19b8
  - Linux 6894717a1ea363c5a27010ba604f957c309d282d
  - Linux fb91ce37dc9a37ea23cf32b6d7b667004e93d4c5
  - Linux a9584c897d1cba6265c78010bbb45ca5722c88bc
  - Linux 0f67ca2a80acf8b207240405b7f72d660665d3df
  - Linux de5a44f351ca7efd9add9851b218f5353e2224b7
  - Linux 91e2a2e4d1336333804cd31162984f01ad8cc70f
  - Linux 7b277bd569bb6a2777f0014f84b4344f444fd49d
  - Linux >= 5.4.297 < 5.5
  - Linux >= 5.10.231 < 5.11
  - Linux >= 5.15.174 < 5.16
  - Linux >= 6.1.120 < 6.2
  - Linux >= 6.6.64 < 6.7
  - Linux >= 6.11.11 < 6.12
  - Linux >= 6.12.2 < 6.13
  - Linux 6.13
published: '2026-09-25'
updated: '2026-09-25'
sourceUpdated: '2026-09-25T11:17:25.427'
source: NVD
sourceUrl: 'https://nvd.nist.gov/vuln/detail/CVE-2026-97975'
references:
  - url: 'https://git.kernel.org/stable/c/9b851b09b392da68bd715601f10a5adb2d8d19b8'
    label: 416baaa9-dc9f-4396-8d5f-8c081fb06d67
  - url: 'https://git.kernel.org/stable/c/9e9ece97b8e716890793de261574b8efef7d8702'
    label: 416baaa9-dc9f-4396-8d5f-8c081fb06d67
  - url: 'https://git.kernel.org/stable/c/eeabdb25c3209569367e99a85ca9a503b64a646d'
    label: 416baaa9-dc9f-4396-8d5f-8c081fb06d67
tags:
  - nvd
  - cve.org
ingestedAt: '2026-09-25T11:06:38.870Z'
---

## Overview

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's klist and
clears knode_parent. Subsequently, device_del() calls
klist_del(&dev->p->knode_parent) using the stale parent snapshot, causing
klist_put() to dereference knode_klist(n)->put on an already removed node,
resulting in a NULL pointer dereference.

This race was introduced by commit 27aabf27fd01 ("Bluetooth: fix
use-after-free in device_for_each_child()"), 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->dev outlived its parent hdev->dev when child devices held
references to conn->dev, because conn->dev only held a reference to
hdev->dev while registered in sysfs.

Fix the issue properly by taking an explicit reference to the parent device
with get_device(&hdev->dev) 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->dev remains valid for the entire lifecycle of conn->dev,
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.

## Remediation

Refer to the linked advisories for vendor-supplied fixes and affected version ranges.