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

No CVSS v4.0

Attack Vector Local

Attack Complexity Low

Privileges Required Low

Scope Unchanged

Confidentiality Impact None

Integrity Impact None

Availability Impact High

User Interaction None

No CVSS v3.0

No CVSS v2

This CVE is not in the KEV list.

The EPSS score is 0.00025.

Key SSVC decision points have not yet been added.

Default status is the baseline for the product, each version can override it (e.g. patched versions marked unaffected).

Vendor Product Default status Versions
Linux Linux unaffected
Version Status Constraints
182ee45da083db4e3e621541ccf255bfa9652214 affected < a30c074f0b5b7f909a15c978fbc96a29e2f94e42
182ee45da083db4e3e621541ccf255bfa9652214 affected < ba3ba53ce1f76fc372b8f918fece4f9b1e41acd4
182ee45da083db4e3e621541ccf255bfa9652214 affected < 94d9ba9f9888b748d4abd2aa1547af56ae85f772
Linux Linux affected
Version Status Constraints
5.17 affected —
0 unaffected < 5.17
6.4.16 unaffected ≤ 6.4.*
6.5.3 unaffected ≤ 6.5.*
6.6 unaffected ≤ *

No data.

No data.

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Advisories

No advisories yet.

Fixes

Solution

No solution given by the vendor.

Workaround

No workaround given by the vendor.

References
Link Providers
https://git.kernel.org/stable/c/94d9ba9f9888b748d4abd2aa1547af56ae85f772 cve-icon cve-icon
https://git.kernel.org/stable/c/a30c074f0b5b7f909a15c978fbc96a29e2f94e42 cve-icon cve-icon
https://git.kernel.org/stable/c/ba3ba53ce1f76fc372b8f918fece4f9b1e41acd4 cve-icon cve-icon
https://lore.kernel.org/linux-cve-announce/2025120845-CVE-2023-53762-01bc@gregkh/T cve-icon
https://nvd.nist.gov/vuln/detail/CVE-2023-53762 cve-icon
https://www.cve.org/CVERecord?id=CVE-2023-53762 cve-icon
History

Wed, 10 Dec 2025 12:15:00 +0000

Type Values Removed Values Added
References
Metrics threat_severity

None

 cvssV3_1

{'score': 5.5, 'vector': 'CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:H'}

threat_severity

Moderate

Mon, 08 Dec 2025 02:00:00 +0000

Type Values Removed Values Added
Description 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 ==================================================================
Title Bluetooth: hci_sync: Fix UAF in hci_disconnect_all_sync
First Time appeared Linux
Linux linux Kernel
CPEs cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*
Vendors & Products Linux
Linux linux Kernel
References

Projects

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cve-icon MITRE

Status: PUBLISHED

Assigner: Linux

Published:

Updated: 2025-12-08T01:19:23.927Z

Reserved: 2025-12-08T01:18:04.281Z

Link: CVE-2023-53762

cve-icon Vulnrichment

No data.

cve-icon NVD

Status : Awaiting Analysis

Published: 2025-12-08T02:15:52.043

Modified: 2025-12-08T18:26:19.900

Link: CVE-2023-53762

cve-icon Redhat

Severity : Moderate

Publid Date: 2025-12-08T00:00:00Z

Links: CVE-2023-53762 - Bugzilla

cve-icon OpenCVE Enrichment

No data.

Weaknesses

No weakness.