---
id: CVE-2026-98109
title: |-
  In the Linux kernel, the following vulnerability has been resolved:

  Bluetooth: hci_core: Fix race condition during device registration

  In hci_register_dev(), the power_on work item is queued to
  hdev->req_workqueue before initializing h…
summary: |-
  In the Linux kernel, the following vulnerability has been resolved:

  Bluetooth: hci_core: Fix race condition during device registration

  In hci_register_dev(), the power_on work item is queued to
  hdev->req_workqueue before initializing h…
severity: medium
cvss: 4.7
cvssVector: 'CVSS:3.1/AV:L/AC:H/PR:L/UI:N/S:U/C:N/I:N/A:H'
cwe:
  - CWE-362
  - CWE-908
vendor: linux
product: linux_kernel
affected:
  - 'linux_kernel >= 6.4.16, < 6.5'
  - 'linux_kernel >= 6.5.3, < 6.12.111'
  - 'linux_kernel >= 6.13, < 6.18.53'
  - 'linux_kernel >= 6.19, < 7.2.7'
  - linux_kernel = 7.3
patched:
  - linux_kernel 7.2.7
published: '2026-09-25'
updated: '2026-10-03'
sourceUpdated: '2026-10-03T11:18:32.990'
source: NVD
sourceUrl: 'https://nvd.nist.gov/vuln/detail/CVE-2026-98109'
references:
  - url: 'https://git.kernel.org/stable/c/57938bbdb9bf7fd41cbd5cd509ec10c4b22bec18'
    label: 416baaa9-dc9f-4396-8d5f-8c081fb06d67
  - url: 'https://git.kernel.org/stable/c/593e64f64a20b25e4042c3ee863119eb7f991785'
    label: 416baaa9-dc9f-4396-8d5f-8c081fb06d67
  - url: 'https://git.kernel.org/stable/c/a11ebe8dc0333fb870bbbb656b34690e87ee3f98'
    label: 416baaa9-dc9f-4396-8d5f-8c081fb06d67
  - url: 'https://git.kernel.org/stable/c/b1faf348c29e6f8302ec7769cbf1c1ef05be014f'
    label: 416baaa9-dc9f-4396-8d5f-8c081fb06d67
  - url: 'https://git.kernel.org/stable/c/d427b1c71d9798083e954d3c13469dc0a2305868'
    label: 416baaa9-dc9f-4396-8d5f-8c081fb06d67
  - url: >-
      https://security.access.redhat.com/data/csaf/v2/vex/2026/cve-2026-98109.json
  - url: 'https://access.redhat.com/security/cve/CVE-2026-98109'
  - url: 'https://bugzilla.redhat.com/show_bug.cgi?id=2541338'
  - url: 'https://www.cve.org/CVERecord?id=CVE-2026-98109'
  - url: 'https://nvd.nist.gov/vuln/detail/CVE-2026-98109'
  - url: >-
      https://git.kernel.org/pub/scm/linux/security/vulns.git/plain/cve/published/2026/CVE-2026-98109.mbox
tags:
  - nvd
  - cve.org
  - csaf
  - vex
  - red-hat
epss: 0.00089
epssPercentile: 0.00389
scores:
  nvd: 4.7
  vendor: 5.5
ingestedAt: '2026-09-25T11:06:38.824Z'
---

## Overview

In the Linux kernel, the following vulnerability has been resolved:

Bluetooth: hci_core: Fix race condition during device registration

In hci_register_dev(), the power_on work item is queued to
hdev->req_workqueue before initializing hdev->adv_monitors_idr and
registering the MSFT extension via msft_register(). For devices marked with
quirks such as HCI_QUIRK_RAW_DEVICE, the HCI_UNCONFIGURED flag is set on
the device. When the power_on work item runs concurrently on another CPU,
hci_power_on() detects that the device is unconfigured and immediately
invokes hci_dev_do_close(), which calls msft_do_close().

Concurrently, msft_register() allocates the msft structure and exposes it
to hdev->msft_data prior to calling mutex_init(&msft->filter_lock). If
msft_do_close() executes while hdev->msft_data is already assigned but the
mutex has not yet been initialized, mutex_lock(&msft->filter_lock) operates
on an uninitialized mutex, triggering a DEBUG_LOCKS warning:

DEBUG_LOCKS_WARN_ON(lock->magic != lock)
WARNING: kernel/locking/mutex.c:625 at __mutex_lock_common
kernel/locking/mutex.c:625 [inline]
WARNING: kernel/locking/mutex.c:625 at __mutex_lock+0x12d8/0x1550
kernel/locking/mutex.c:821
...
Call Trace:
 <TASK>
 msft_do_close+0x308/0x7b0 net/bluetooth/msft.c:693
 hci_dev_close_sync+0x86b/0x10a0 net/bluetooth/hci_sync.c:5522
 hci_dev_do_close net/bluetooth/hci_core.c:499 [inline]
 hci_power_on+0x32c/0x750 net/bluetooth/hci_core.c:937
 process_one_work kernel/workqueue.c:3322 [inline]
 process_scheduled_works+0xa8e/0x14e0 kernel/workqueue.c:3405
 worker_thread+0x92d/0xe10 kernel/workqueue.c:3486
 kthread+0x388/0x470 kernel/kthread.c:436
 ret_from_fork+0x514/0xb70 arch/x86/kernel/process.c:158
 ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:245
 </TASK>

Fix this by moving the queue_work() call in hci_register_dev() to after
idr_init(&hdev->adv_monitors_idr) and msft_register(hdev) so that device
structures and extensions are fully initialized before asynchronous tasks
can access them. Additionally, assign hdev->msft_data in msft_register()
only after mutex_init(&msft->filter_lock) has completed.

## Affected

- `linux_kernel >= 6.4.16, < 6.5`
- `linux_kernel >= 6.5.3, < 6.12.111`
- `linux_kernel >= 6.13, < 6.18.53`
- `linux_kernel >= 6.19, < 7.2.7`
- `linux_kernel = 7.3`

## Remediation

Upgrade past the affected range:

- `linux_kernel 7.2.7`

## Vendor advisories

- **Red Hat VEX** · Moderate · affected: Red Hat Enterprise Linux 10, Red Hat Enterprise Linux 6, Red Hat Enterprise Linux 9, Red Hat OpenShift Container Platform 4 · no fix planned: Red Hat Enterprise Linux 6, Red Hat Enterprise Linux 10, Red Hat Enterprise Linux 9, Red Hat OpenShift Container Platform 4 · updated 2026-10-17 · [vex](https://security.access.redhat.com/data/csaf/v2/vex/2026/cve-2026-98109.json)