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Fencer Vulns
high 8.8

CVE-2023-53762 json

Bluetooth: hci_sync: Fix UAF in hci_disconnect_all_sync

published 2025-12-08 11 mo ago modified 2026-10-03 37 d ago also EUVD-2023-60066

cvss
8.8
version 3.1, CNA
cisa kev
Not listed
not in CISA's catalog
epss
0.3%
EPSS 0.3% chance of exploitation in 30 days, percentile 18%
public exploits
0
none known

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 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 ==================================================================

Patch / fix

  • Linux Linux 6.1.189, 6.4.16, 6.5.3, 6.6
  • linux Debian 12 6.1.190-1
  • linux Debian 14, Debian 13 6.5.3-1

debian advisories DEBIAN-CVE-2023-53762

  • kernel-rt RHEL 8 4.18.0-553.105.1.rt7.446.el8_10
  • kernel-rt-kvm RHEL 8 4.18.0-553.105.1.rt7.446.el8_10
  • kernel-rt-core RHEL 8 4.18.0-553.105.1.rt7.446.el8_10
  • kernel-rt-modules RHEL 8 4.18.0-553.105.1.rt7.446.el8_10
  • kernel-rt-debug-kvm RHEL 8 4.18.0-553.105.1.rt7.446.el8_10
  • kernel-rt-debug-core RHEL 8 4.18.0-553.105.1.rt7.446.el8_10
  • kernel-rt-debug-modules RHEL 8 4.18.0-553.105.1.rt7.446.el8_10
  • kernel-rt-modules-extra RHEL 8 4.18.0-553.105.1.rt7.446.el8_10

red hat advisories RHSA-2026:3358RHSA-2026:3267RHSA-2026:2821RHSA-2026:2720RHSA-2024:2394

  • kernel-rt Linux Micro 6.1, Linux Micro 6.0 6.4.0-40.1
  • kernel-source-rt Linux Micro 6.1, Linux Micro 6.0 6.4.0-40.1
  • kernel-source Linux Micro 6.1, Linux Micro 6.0 6.4.0-39.1
  • kernel-default Linux Micro 6.1, Linux Micro 6.0 6.4.0-39.1
  • kernel-kvmsmall Linux Micro 6.1, Linux Micro 6.0 6.4.0-39.1
  • kernel-default-base Linux Micro 6.1, Linux Micro 6.0 6.4.0-39.1.21.16
  • kernel-64kb SLE Module for Basesystem 15 SP7 6.4.0-150700.53.28.1
  • kernel-syms SLE Module for Development Tools 15 SP7 6.4.0-150700.53.28.1

suse advisories SUSE-SU-2026:20845-1SUSE-SU-2026:20876-1SUSE-SU-2026:20477-1SUSE-SU-2026:20498-1SUSE-SU-2026:0315-1SUSE-SU-2026:0293-1

  • kernel-rt AlmaLinux 8 4.18.0-553.105.1.rt7.446.el8_10
  • kernel-rt-core AlmaLinux 8 4.18.0-553.105.1.rt7.446.el8_10
  • kernel-rt-modules AlmaLinux 8 4.18.0-553.105.1.rt7.446.el8_10
  • kernel-rt-debug-core AlmaLinux 8 4.18.0-553.105.1.rt7.446.el8_10
  • kernel-rt-debug-modules AlmaLinux 8 4.18.0-553.105.1.rt7.446.el8_10
  • kernel-rt-modules-extra AlmaLinux 8 4.18.0-553.105.1.rt7.446.el8_10
  • kernel-rt-debug-modules-extra AlmaLinux 8 4.18.0-553.105.1.rt7.446.el8_10
  • kernel AlmaLinux 8 4.18.0-553.105.1.el8_10

almalinux advisories ALSA-2026:2821ALSA-2026:2720

  • kernel-rt Rocky Linux 8 4.18.0-553.105.1.rt7.446.el8_10
  • kernel Rocky Linux 8 4.18.0-553.105.1.el8_10

rocky linux advisories RLSA-2026:2821RLSA-2026:2720

Vendor advisories

What the vendors themselves say about their products: affected, fixed or not affected, and what to do.

red hat product security vex CVE-2023-53762 updated cvss 7.0

kernel: Linux kernel Bluetooth: Denial of Service due to use-after-free in connection handling

  • Red Hat Enterprise Linux 9 kernel-rt, kernel-rt-kvm, kernel-rt-core, kernel-rt-modules, kernel-rt-debug-kvm, kernel-rt-debug-core, +12 more
    affected: workaround, no fix available
  • Red Hat Enterprise Linux AppStream (v. 9) rv 5.14.0-427.13.1.el9_4, perf 5.14.0-427.13.1.el9_4, rtla 5.14.0-427.13.1.el9_4, kernel-devel-matched 5.14.0-427.13.1.el9_4, kernel-64k-devel-matched 5.14.0-427.13.1.el9_4, kernel-debug-devel-matched 5.14.0-427.13.1.el9_4, +6 more
    fixed: vendor fix RHSA-2024:2394
  • Red Hat Enterprise Linux AppStream E4S (v.9.2) perf 5.14.0-284.158.1.el9_2, rtla 5.14.0-284.158.1.el9_2, kernel-devel-matched 5.14.0-284.158.1.el9_2, kernel-64k-devel-matched 5.14.0-284.158.1.el9_2, kernel-debug-devel-matched 5.14.0-284.158.1.el9_2, kernel-debuginfo-common-s390x 5.14.0-284.158.1.el9_2, +5 more
    fixed: vendor fix RHSA-2026:3267
  • Red Hat Enterprise Linux BaseOS (v. 8) perf 4.18.0-553.105.1.el8_10, kernel 4.18.0-553.105.1.el8_10, bpftool 4.18.0-553.105.1.el8_10, kernel-core 4.18.0-553.105.1.el8_10, kernel-tools 4.18.0-553.105.1.el8_10, python3-perf 4.18.0-553.105.1.el8_10, +15 more
    fixed: vendor fix RHSA-2026:2720
  • Red Hat Enterprise Linux BaseOS (v. 9) bpftool 7.3.0-427.13.1.el9_4, kernel 5.14.0-427.13.1.el9_4, kernel-64k 5.14.0-427.13.1.el9_4, kernel-core 5.14.0-427.13.1.el9_4, kernel-tools 5.14.0-427.13.1.el9_4, python3-perf 5.14.0-427.13.1.el9_4, +28 more
    fixed: vendor fix RHSA-2024:2394
  • Red Hat Enterprise Linux BaseOS E4S (v.9.2) bpftool 7.0.0-284.158.1.el9_2, kernel 5.14.0-284.158.1.el9_2, kernel-64k 5.14.0-284.158.1.el9_2, kernel-core 5.14.0-284.158.1.el9_2, kernel-tools 5.14.0-284.158.1.el9_2, python3-perf 5.14.0-284.158.1.el9_2, +28 more
    fixed: vendor fix RHSA-2026:3267
  • Red Hat Enterprise Linux CRB (v. 8) kernel-debuginfo-common-x86_64 4.18.0-553.105.1.el8_10, kernel-debuginfo-common-aarch64 4.18.0-553.105.1.el8_10, kernel-debuginfo-common-ppc64le 4.18.0-553.105.1.el8_10
    fixed: vendor fix RHSA-2026:2720
  • Red Hat Enterprise Linux CRB (v. 9) libperf 5.14.0-427.13.1.el9_4, kernel-debuginfo-common-s390x 5.14.0-427.13.1.el9_4, kernel-debuginfo-common-x86_64 5.14.0-427.13.1.el9_4, kernel-debuginfo-common-aarch64 5.14.0-427.13.1.el9_4, kernel-debuginfo-common-ppc64le 5.14.0-427.13.1.el9_4
    fixed: vendor fix RHSA-2024:2394
show 6 more
  • Red Hat Enterprise Linux NFV (v. 8) kernel-rt 4.18.0-553.105.1.rt7.446.el8_10, kernel-rt-kvm 4.18.0-553.105.1.rt7.446.el8_10, kernel-rt-core 4.18.0-553.105.1.rt7.446.el8_10, kernel-rt-modules 4.18.0-553.105.1.rt7.446.el8_10, kernel-rt-debug-kvm 4.18.0-553.105.1.rt7.446.el8_10, kernel-rt-debug-core 4.18.0-553.105.1.rt7.446.el8_10, +4 more
    fixed: vendor fix RHSA-2026:2821
  • Red Hat Enterprise Linux NFV (v. 9) kernel-rt 5.14.0-427.13.1.el9_4, kernel-rt-kvm 5.14.0-427.13.1.el9_4, kernel-rt-core 5.14.0-427.13.1.el9_4, kernel-rt-modules 5.14.0-427.13.1.el9_4, kernel-rt-debug-kvm 5.14.0-427.13.1.el9_4, kernel-rt-debug-core 5.14.0-427.13.1.el9_4, +6 more
    fixed: vendor fix RHSA-2024:2394
  • Red Hat Enterprise Linux Real Time E4S (v.9.2) kernel-rt 5.14.0-284.158.1.rt14.443.el9_2, kernel-rt-core 5.14.0-284.158.1.rt14.443.el9_2, kernel-rt-modules 5.14.0-284.158.1.rt14.443.el9_2, kernel-rt-debug-core 5.14.0-284.158.1.rt14.443.el9_2, kernel-rt-modules-core 5.14.0-284.158.1.rt14.443.el9_2, kernel-rt-debug-modules 5.14.0-284.158.1.rt14.443.el9_2, +4 more Red Hat Enterprise Linux Real Time for NFV E4S (v.9.2) kernel-rt 5.14.0-284.158.1.rt14.443.el9_2, kernel-rt-kvm 5.14.0-284.158.1.rt14.443.el9_2, kernel-rt-core 5.14.0-284.158.1.rt14.443.el9_2, kernel-rt-modules 5.14.0-284.158.1.rt14.443.el9_2, kernel-rt-debug-kvm 5.14.0-284.158.1.rt14.443.el9_2, kernel-rt-debug-core 5.14.0-284.158.1.rt14.443.el9_2, +6 more
    fixed: vendor fix RHSA-2026:3358
  • Red Hat Enterprise Linux RT (v. 8) kernel-rt 4.18.0-553.105.1.rt7.446.el8_10, kernel-rt-core 4.18.0-553.105.1.rt7.446.el8_10, kernel-rt-modules 4.18.0-553.105.1.rt7.446.el8_10, kernel-rt-debug-core 4.18.0-553.105.1.rt7.446.el8_10, kernel-rt-debug-modules 4.18.0-553.105.1.rt7.446.el8_10, kernel-rt-modules-extra 4.18.0-553.105.1.rt7.446.el8_10, +2 more
    fixed: vendor fix RHSA-2026:2821
  • Red Hat Enterprise Linux RT (v. 9) kernel-rt 5.14.0-427.13.1.el9_4, kernel-rt-core 5.14.0-427.13.1.el9_4, kernel-rt-modules 5.14.0-427.13.1.el9_4, kernel-rt-debug-core 5.14.0-427.13.1.el9_4, kernel-rt-modules-core 5.14.0-427.13.1.el9_4, kernel-rt-debug-modules 5.14.0-427.13.1.el9_4, +4 more
    fixed: vendor fix RHSA-2024:2394
  • Red Hat Enterprise Linux 6 perf, kernel, python-perf, kernel-kdump, kernel-firmware, kernel-bootwrapper, +1 more Red Hat Enterprise Linux 7 perf, kernel, bpftool, kernel-rt, python-perf, kernel-kdump, +8 more Red Hat Enterprise Linux 10 kernel
    not affected: vulnerable code not present

Red Hat CSAF VEX © Red Hat, Inc., from https://security.access.redhat.com/data/csaf/v2/vex/; changed: reduced to product statuses and remediations. CC BY 4.0 · csaf

CISA SSVC

Exploitation
none
Automatable
no
Technical impact
partial
Assessed
4 mo ago

Exploit prediction

0.27% chance of exploitation in the next 30 days, higher than 18% of all scored CVEs (FIRST EPSS, 2026-11-08).

CVSS scores

assigned by version score vector
CNA 3.1 8.8 CVSS:3.1/AV:A/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H

Affected products

  • Linux Linux

Classification

Technology feeds

References

Sources

Fencer Vulns keeps one entry per vulnerability: the CVE id wins, then GHSA, and records that alias each other are merged, except that two CVEs always keep separate entries. The same data is available as JSON.