Reference page — cumulative record through Wednesday, August 19, 2026 UTC. Reference pages update as the archive grows; only dated daily editions are immutable pages of record.
Linux Linux — Bluetooth: hci_event: call disconnect callback before deleting conn
AV AC PR UI S C I A CVSS EPSS %ile KEV
L L L N U H H H 7.8 .0023 13.5 —
AFFECTED
Product Versions Fixed
Linux b8d290525e3972b5e876b2649a42bf4081d753fe – —
Linux 5.7 – 5.15.200
TIMELINE
Oct 7 Reserved by Linux
Oct 7 Published (CNA: Linux)
Aug 4 RESCORED — CVE-2023-53673 (Linux). CVSS 8.8 → 7.8 (NVD).
Description
In the Linux kernel, the following vulnerability has been resolved:
Bluetooth: hci_event: call disconnect callback before deleting conn
In hci_cs_disconnect, we do hci_conn_del even if disconnection failed.
ISO, L2CAP and SCO connections refer to the hci_conn without
hci_conn_get, so disconn_cfm must be called so they can clean up their
conn, otherwise use-after-free occurs.
ISO:
==========================================================
iso_sock_connect:880: sk 00000000eabd6557
iso_connect_cis:356: 70:1a:b8:98:ff:a2 -> 28:3d:c2:4a:7e:da
...
iso_conn_add:140: hcon 000000001696f1fd conn 00000000b6251073
hci_dev_put:1487: hci0 orig refcnt 17
__iso_chan_add:214: conn 00000000b6251073
iso_sock_clear_timer:117: sock 00000000eabd6557 state 3
...
hci_rx_work:4085: hci0 Event packet
hci_event_packet:7601: hci0: event 0x0f
hci_cmd_status_evt:4346: hci0: opcode 0x0406
hci_cs_disconnect:2760: hci0: status 0x0c
hci_sent_cmd_data:3107: hci0 opcode 0x0406
hci_conn_del:1151: hci0 hcon 000000001696f1fd handle 2560
hci_conn_unlink:1102: hci0: hcon 000000001696f1fd
hci_conn_drop:1451: hcon 00000000d8521aaf orig refcnt 2
hci_chan_list_flush:2780: hcon 000000001696f1fd
hci_dev_put:1487: hci0 orig refcnt 21
hci_dev_put:1487: hci0 orig refcnt 20
hci_req_cmd_complete:3978: opcode 0x0406 status 0x0c
... <no iso_* activity on sk/conn> ...
iso_sock_sendmsg:1098: sock 00000000dea5e2e0, sk 00000000eabd6557
BUG: kernel NULL pointer dereference, address: 0000000000000668
PGD 0 P4D 0
Oops: 0000 [#1] PREEMPT SMP PTI
Hardware name: QEMU Standard PC (Q35 + ICH9, 2009), BIOS 1.16.2-1.fc38 04/01/2014
RIP: 0010:iso_sock_sendmsg (net/bluetooth/iso.c:1112) bluetooth
==========================================================
L2CAP:
==================================================================
hci_cmd_status_evt:4359: hci0: opcode 0x0406
hci_cs_disconnect:2760: hci0: status 0x0c
hci_sent_cmd_data:3085: hci0 opcode 0x0406
hci_conn_del:1151: hci0 hcon ffff88800c999000 handle 3585
hci_conn_unlink:1102: hci0: hcon ffff88800c999000
hci_chan_list_flush:2780: hcon ffff88800c999000
hci_chan_del:2761: hci0 hcon ffff88800c999000 chan ffff888018ddd280
...
BUG: KASAN: slab-use-after-free in hci_send_acl+0x2d/0x540 [bluetooth]
Read of size 8 at addr ffff888018ddd298 by task bluetoothd/1175
CPU: 0 PID: 1175 Comm: bluetoothd Tainted: G E 6.4.0-rc4+ #2
Hardware name: QEMU Standard PC (Q35 + ICH9, 2009), BIOS 1.16.2-1.fc38 04/01/2014
Call Trace:
<TASK>
dump_stack_lvl+0x5b/0x90
print_report+0xcf/0x670
? __virt_addr_valid+0xf8/0x180
? hci_send_acl+0x2d/0x540 [bluetooth]
kasan_report+0xa8/0xe0
? hci_send_acl+0x2d/0x540 [bluetooth]
hci_send_acl+0x2d/0x540 [bluetooth]
? __pfx___lock_acquire+0x10/0x10
l2cap_chan_send+0x1fd/0x1300 [bluetooth]
? l2cap_sock_sendmsg+0xf2/0x170 [bluetooth]
? __pfx_l2cap_chan_send+0x10/0x10 [bluetooth]
? lock_release+0x1d5/0x3c0
? mark_held_locks+0x1a/0x90
l2cap_sock_sendmsg+0x100/0x170 [bluetooth]
sock_write_iter+0x275/0x280
? __pfx_sock_write_iter+0x10/0x10
? __pfx___lock_acquire+0x10/0x10
do_iter_readv_writev+0x176/0x220
? __pfx_do_iter_readv_writev+0x10/0x10
? find_held_lock+0x83/0xa0
? selinux_file_permission+0x13e/0x210
do_iter_write+0xda/0x340
vfs_writev+0x1b4/0x400
? __pfx_vfs_writev+0x10/0x10
? __seccomp_filter+0x112/0x750
? populate_seccomp_data+0x182/0x220
? __fget_light+0xdf/0x100
? do_writev+0x19d/0x210
do_writev+0x19d/0x210
? __pfx_do_writev+0x10/0x10
? mark_held_locks+0x1a/0x90
do_syscall_64+0x60/0x90
? lockdep_hardirqs_on_prepare+0x149/0x210
? do_syscall_64+0x6c/0x90
? lockdep_hardirqs_on_prepare+0x149/0x210
entry_SYSCALL_64_after_hwframe+0x72/0xdc
RIP: 0033:0x7ff45cb23e64
Code: 15 d1 1f 0d 00 f7 d8 64 89 02 48 c7 c0 ff ff ff ff eb b8 0f 1f 00 f3 0f 1e fa 80 3d 9d a7 0d 00 00 74 13 b8 14 00 00 00 0f 05 <48> 3d 00 f0 ff ff 77 54 c3 0f 1f 00 48 83 ec 28 89 54 24 1c 48 89
RSP: 002b:00007fff21ae09b8 EFLAGS: 00000202 ORIG_RAX: 0000000000000014
RAX: ffffffffffffffda RBX:
---truncated---
Lifecycle
Complete event history — 3 events, chronological
| Date | Event | Detail |
| October 7, 2025 | Reserved | Reserved by Linux |
| October 7, 2025 | Published | Published (CNA: Linux) |
| August 4, 2026 | RESCORED | RESCORED — CVE-2023-53673 (Linux). CVSS 8.8 → 7.8 (NVD). |
Affected
Affected products and packages — 2 rows
| Vendor | Product / Package | Ecosystem | Version introduced | Fixed |
| Linux | Linux | — | b8d290525e3972b5e876b2649a42bf4081d753fe | — |
| Linux | Linux | — | 5.7 | 5.15.200 |
About this page
This is a reference page, not a dated page of record. It assembles the complete lifecycle of CVE-2023-53673 from the CVE Program record, NVD enrichment, the CISA KEV catalog, EPSS, and OSV advisories. The box score's numbers (CVSS, EPSS, KEV status) are current as of Wednesday, August 19, 2026 UTC and are re-derived as the archive grows; only dated daily editions are immutable pages of record. The authoritative source for this identifier is cve.org.