---
id: CVE-2023-53520
title: |-
  In the Linux kernel, the following vulnerability has been resolved:

  Bluetooth: Fix hci_suspend_sync crash

  If hci_unregister_dev() frees the hci_dev object but hci_suspend_notifier
  may still be accessing it, it can cause the program to …
summary: |-
  In the Linux kernel, the following vulnerability has been resolved:

  Bluetooth: Fix hci_suspend_sync crash

  If hci_unregister_dev() frees the hci_dev object but hci_suspend_notifier
  may still be accessing it, it can cause the program to …
severity: high
cvss: 7.8
cvssVector: 'CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H'
cwe:
  - CWE-362
vendor: linux
product: linux_kernel
affected:
  - 'linux_kernel >= 5.7, < 6.1.55'
  - 'linux_kernel >= 6.2, < 6.5.5'
patched:
  - linux_kernel 6.5.5
published: '2025-10-01'
updated: '2026-10-15'
sourceUpdated: '2026-10-15T22:17:42.087'
source: NVD
sourceUrl: 'https://nvd.nist.gov/vuln/detail/CVE-2023-53520'
references:
  - url: 'https://git.kernel.org/stable/c/06e2b5ad72b60f90bfe565c201346532e271f484'
    label: 416baaa9-dc9f-4396-8d5f-8c081fb06d67
  - url: 'https://git.kernel.org/stable/c/573ebae162111063eedc6c838a659ba628f66a0f'
    label: 416baaa9-dc9f-4396-8d5f-8c081fb06d67
  - url: 'https://git.kernel.org/stable/c/e1fa25a91091bbed691ba2996a6cee809e3309a2'
    label: 416baaa9-dc9f-4396-8d5f-8c081fb06d67
  - url: 'https://git.kernel.org/stable/c/f9c8ce5d665653e3cf71a76349d41d7a7f7947e6'
    label: 416baaa9-dc9f-4396-8d5f-8c081fb06d67
tags:
  - nvd
  - cve.org
epss: 0.00117
epssPercentile: 0.01656
ssvc:
  exploitation: none
  automatable: 'no'
  technicalImpact: total
  timestamp: '2026-10-15T21:35:21.506402Z'
ingestedAt: '2026-10-15T22:48:25.406Z'
---

## Overview

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

Bluetooth: Fix hci_suspend_sync crash

If hci_unregister_dev() frees the hci_dev object but hci_suspend_notifier
may still be accessing it, it can cause the program to crash.
Here's the call trace:
  <4>[102152.653246] Call Trace:
  <4>[102152.653254]  hci_suspend_sync+0x109/0x301 [bluetooth]
  <4>[102152.653259]  hci_suspend_dev+0x78/0xcd [bluetooth]
  <4>[102152.653263]  hci_suspend_notifier+0x42/0x7a [bluetooth]
  <4>[102152.653268]  notifier_call_chain+0x43/0x6b
  <4>[102152.653271]  __blocking_notifier_call_chain+0x48/0x69
  <4>[102152.653273]  __pm_notifier_call_chain+0x22/0x39
  <4>[102152.653276]  pm_suspend+0x287/0x57c
  <4>[102152.653278]  state_store+0xae/0xe5
  <4>[102152.653281]  kernfs_fop_write+0x109/0x173
  <4>[102152.653284]  __vfs_write+0x16f/0x1a2
  <4>[102152.653287]  ? selinux_file_permission+0xca/0x16f
  <4>[102152.653289]  ? security_file_permission+0x36/0x109
  <4>[102152.653291]  vfs_write+0x114/0x21d
  <4>[102152.653293]  __x64_sys_write+0x7b/0xdb
  <4>[102152.653296]  do_syscall_64+0x59/0x194
  <4>[102152.653299]  entry_SYSCALL_64_after_hwframe+0x5c/0xc1

This patch holds the reference count of the hci_dev object while
processing it in hci_suspend_notifier to avoid potential crash
caused by the race condition.

## Affected

- `linux_kernel >= 5.7, < 6.1.55`
- `linux_kernel >= 6.2, < 6.5.5`

## Remediation

Upgrade past the affected range:

- `linux_kernel 6.5.5`