---
id: CVE-2023-53762
title: |-
  In the Linux kernel, the following vulnerability has been resolved:

  Bluetooth: hci_sync: Fix UAF in hci_disconnect_all_sync

  Use-after-free can occur in hci_disconnect_all_sync if a connection is
  deleted by concurrent processing of a co…
summary: |-
  In the Linux kernel, the following vulnerability has been resolved:

  Bluetooth: hci_sync: Fix UAF in hci_disconnect_all_sync

  Use-after-free can occur in hci_disconnect_all_sync if a connection is
  deleted by concurrent processing of a co…
severity: high
cvss: 8.8
cvssVector: 'CVSS:3.1/AV:A/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H'
vendor: Linux
product: Linux
affected:
  - >-
    Linux >= 182ee45da083db4e3e621541ccf255bfa9652214 <
    5e3ee972f185eb7957ce789b3bf13a3cb790f178
  - >-
    Linux >= 182ee45da083db4e3e621541ccf255bfa9652214 <
    a30c074f0b5b7f909a15c978fbc96a29e2f94e42
  - >-
    Linux >= 182ee45da083db4e3e621541ccf255bfa9652214 <
    ba3ba53ce1f76fc372b8f918fece4f9b1e41acd4
  - >-
    Linux >= 182ee45da083db4e3e621541ccf255bfa9652214 <
    94d9ba9f9888b748d4abd2aa1547af56ae85f772
  - Linux 5.17
published: '2025-12-08'
updated: '2026-10-03'
sourceUpdated: '2026-10-03T11:17:28.767'
source: NVD
sourceUrl: 'https://nvd.nist.gov/vuln/detail/CVE-2023-53762'
references:
  - url: 'https://git.kernel.org/stable/c/5e3ee972f185eb7957ce789b3bf13a3cb790f178'
    label: 416baaa9-dc9f-4396-8d5f-8c081fb06d67
  - url: 'https://git.kernel.org/stable/c/94d9ba9f9888b748d4abd2aa1547af56ae85f772'
    label: 416baaa9-dc9f-4396-8d5f-8c081fb06d67
  - url: 'https://git.kernel.org/stable/c/a30c074f0b5b7f909a15c978fbc96a29e2f94e42'
    label: 416baaa9-dc9f-4396-8d5f-8c081fb06d67
  - url: 'https://git.kernel.org/stable/c/ba3ba53ce1f76fc372b8f918fece4f9b1e41acd4'
    label: 416baaa9-dc9f-4396-8d5f-8c081fb06d67
tags:
  - nvd
  - cve.org
ssvc:
  exploitation: none
  automatable: 'no'
  technicalImpact: partial
  timestamp: '2026-06-16T15:46:42.482426Z'
epss: 0.00245
epssPercentile: 0.14317
ingestedAt: '2026-10-03T11:43:42.110Z'
---

## Overview

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

Bluetooth: hci_sync: Fix UAF in hci_disconnect_all_sync

Use-after-free can occur in hci_disconnect_all_sync if a connection is
deleted by concurrent processing of a controller event.

To prevent this the code now tries to iterate over the list backwards
to ensure the links are cleanup before its parents, also it no longer
relies on a cursor, instead it always uses the last element since
hci_abort_conn_sync is guaranteed to call hci_conn_del.

UAF crash log:
==================================================================
BUG: KASAN: slab-use-after-free in hci_set_powered_sync
(net/bluetooth/hci_sync.c:5424) [bluetooth]
Read of size 8 at addr ffff888009d9c000 by task kworker/u9:0/124

CPU: 0 PID: 124 Comm: kworker/u9:0 Tainted: G        W
6.5.0-rc1+ #10
Hardware name: QEMU Standard PC (Q35 + ICH9, 2009), BIOS
1.16.2-1.fc38 04/01/2014
Workqueue: hci0 hci_cmd_sync_work [bluetooth]
Call Trace:
 <TASK>
 dump_stack_lvl+0x5b/0x90
 print_report+0xcf/0x670
 ? __virt_addr_valid+0xdd/0x160
 ? hci_set_powered_sync+0x2c9/0x4a0 [bluetooth]
 kasan_report+0xa6/0xe0
 ? hci_set_powered_sync+0x2c9/0x4a0 [bluetooth]
 ? __pfx_set_powered_sync+0x10/0x10 [bluetooth]
 hci_set_powered_sync+0x2c9/0x4a0 [bluetooth]
 ? __pfx_hci_set_powered_sync+0x10/0x10 [bluetooth]
 ? __pfx_lock_release+0x10/0x10
 ? __pfx_set_powered_sync+0x10/0x10 [bluetooth]
 hci_cmd_sync_work+0x137/0x220 [bluetooth]
 process_one_work+0x526/0x9d0
 ? __pfx_process_one_work+0x10/0x10
 ? __pfx_do_raw_spin_lock+0x10/0x10
 ? mark_held_locks+0x1a/0x90
 worker_thread+0x92/0x630
 ? __pfx_worker_thread+0x10/0x10
 kthread+0x196/0x1e0
 ? __pfx_kthread+0x10/0x10
 ret_from_fork+0x2c/0x50
 </TASK>

Allocated by task 1782:
 kasan_save_stack+0x33/0x60
 kasan_set_track+0x25/0x30
 __kasan_kmalloc+0x8f/0xa0
 hci_conn_add+0xa5/0xa80 [bluetooth]
 hci_bind_cis+0x881/0x9b0 [bluetooth]
 iso_connect_cis+0x121/0x520 [bluetooth]
 iso_sock_connect+0x3f6/0x790 [bluetooth]
 __sys_connect+0x109/0x130
 __x64_sys_connect+0x40/0x50
 do_syscall_64+0x60/0x90
 entry_SYSCALL_64_after_hwframe+0x6e/0xd8

Freed by task 695:
 kasan_save_stack+0x33/0x60
 kasan_set_track+0x25/0x30
 kasan_save_free_info+0x2b/0x50
 __kasan_slab_free+0x10a/0x180
 __kmem_cache_free+0x14d/0x2e0
 device_release+0x5d/0xf0
 kobject_put+0xdf/0x270
 hci_disconn_complete_evt+0x274/0x3a0 [bluetooth]
 hci_event_packet+0x579/0x7e0 [bluetooth]
 hci_rx_work+0x287/0xaa0 [bluetooth]
 process_one_work+0x526/0x9d0
 worker_thread+0x92/0x630
 kthread+0x196/0x1e0
 ret_from_fork+0x2c/0x50
==================================================================

## Remediation

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