Vulnerability · Published Oct 7, 2025 · Assigned by Linux

CVE-2023-53673Bluetooth: hci_event: call disconnect callback before deleting conn

High 8.8

In plain English

A high-severity security flaw in Linux from Linux. There are no confirmed reports of exploitation so far. The chance it is exploited in the next 30 days is estimated at 0.2% (higher than 16% of all known vulnerabilities). Fixed versions are available - upgrade the affected package.

Severity (CVSS 3.1)8.8High
Exploit odds (30 days)0.2%top 83.6% of all CVEs
Exploited in the wildNo reportsCISA SSVC: none
Attack toolingNoneno public tooling known

Official 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---

Affected packages & fixed versions

EcosystemPackageFixed inAdvisory
AlmaLinux:8bpftool4.18.0-553.97.1.el8_10ALSA-2026:1142
AlmaLinux:8kernel4.18.0-553.97.1.el8_10ALSA-2026:1142
AlmaLinux:8kernel-abi-stablelists4.18.0-553.97.1.el8_10ALSA-2026:1142
AlmaLinux:8kernel-core4.18.0-553.97.1.el8_10ALSA-2026:1142
AlmaLinux:8kernel-cross-headers4.18.0-553.97.1.el8_10ALSA-2026:1142
AlmaLinux:8kernel-debug4.18.0-553.97.1.el8_10ALSA-2026:1142
AlmaLinux:8kernel-debug-core4.18.0-553.97.1.el8_10ALSA-2026:1142
AlmaLinux:8kernel-debug-devel4.18.0-553.97.1.el8_10ALSA-2026:1142
AlmaLinux:8kernel-debug-modules4.18.0-553.97.1.el8_10ALSA-2026:1142
AlmaLinux:8kernel-debug-modules-extra4.18.0-553.97.1.el8_10ALSA-2026:1142
AlmaLinux:8kernel-devel4.18.0-553.97.1.el8_10ALSA-2026:1142
AlmaLinux:8kernel-doc4.18.0-553.97.1.el8_10ALSA-2026:1142
AlmaLinux:8kernel-headers4.18.0-553.97.1.el8_10ALSA-2026:1142
AlmaLinux:8kernel-modules4.18.0-553.97.1.el8_10ALSA-2026:1142
AlmaLinux:8kernel-modules-extra4.18.0-553.97.1.el8_10ALSA-2026:1142
AlmaLinux:8kernel-rt4.18.0-553.97.1.rt7.438.el8_10ALSA-2026:1148
AlmaLinux:8kernel-rt-core4.18.0-553.97.1.rt7.438.el8_10ALSA-2026:1148
AlmaLinux:8kernel-rt-debug4.18.0-553.97.1.rt7.438.el8_10ALSA-2026:1148
AlmaLinux:8kernel-rt-debug-core4.18.0-553.97.1.rt7.438.el8_10ALSA-2026:1148
AlmaLinux:8kernel-rt-debug-devel4.18.0-553.97.1.rt7.438.el8_10ALSA-2026:1148
AlmaLinux:8kernel-rt-debug-modules4.18.0-553.97.1.rt7.438.el8_10ALSA-2026:1148
AlmaLinux:8kernel-rt-debug-modules-extra4.18.0-553.97.1.rt7.438.el8_10ALSA-2026:1148
AlmaLinux:8kernel-rt-devel4.18.0-553.97.1.rt7.438.el8_10ALSA-2026:1148
AlmaLinux:8kernel-rt-modules4.18.0-553.97.1.rt7.438.el8_10ALSA-2026:1148
AlmaLinux:8kernel-rt-modules-extra4.18.0-553.97.1.rt7.438.el8_10ALSA-2026:1148
AlmaLinux:8kernel-tools4.18.0-553.97.1.el8_10ALSA-2026:1142
AlmaLinux:8kernel-tools-libs4.18.0-553.97.1.el8_10ALSA-2026:1142
AlmaLinux:8kernel-tools-libs-devel4.18.0-553.97.1.el8_10ALSA-2026:1142
AlmaLinux:8kernel-zfcpdump4.18.0-553.97.1.el8_10ALSA-2026:1142
AlmaLinux:8kernel-zfcpdump-core4.18.0-553.97.1.el8_10ALSA-2026:1142
AlmaLinux:8kernel-zfcpdump-devel4.18.0-553.97.1.el8_10ALSA-2026:1142
AlmaLinux:8kernel-zfcpdump-modules4.18.0-553.97.1.el8_10ALSA-2026:1142
AlmaLinux:8kernel-zfcpdump-modules-extra4.18.0-553.97.1.el8_10ALSA-2026:1142
AlmaLinux:8perf4.18.0-553.97.1.el8_10ALSA-2026:1142
AlmaLinux:8python3-perf4.18.0-553.97.1.el8_10ALSA-2026:1142
Debian:12linux6.1.52-1DEBIAN-CVE-2023-53673
Debian:13linux6.4.11-1DEBIAN-CVE-2023-53673
Debian:14linux6.4.11-1DEBIAN-CVE-2023-53673
Rocky Linux:8kernel0:4.18.0-553.97.1.el8_10RLSA-2026:1142
Rocky Linux:8kernel-rt0:4.18.0-553.97.1.rt7.438.el8_10RLSA-2026:1148
Ubuntu:22.04:LTSlinux5.15.0-185.195USN-8493-1
Ubuntu:22.04:LTSlinux5.15.0-185.195UBUNTU-CVE-2023-53673
Ubuntu:22.04:LTSlinux-allwinner-5.19no fix listedUBUNTU-CVE-2023-53673
Ubuntu:22.04:LTSlinux-aws5.15.0-1111.118UBUNTU-CVE-2023-53673
Ubuntu:22.04:LTSlinux-aws5.15.0-1111.118USN-8493-1
Ubuntu:22.04:LTSlinux-aws-5.19no fix listedUBUNTU-CVE-2023-53673
Ubuntu:22.04:LTSlinux-aws-6.2no fix listedUBUNTU-CVE-2023-53673
Ubuntu:22.04:LTSlinux-aws-6.5no fix listedUBUNTU-CVE-2023-53673
Ubuntu:22.04:LTSlinux-azure5.15.0-1116.125USN-8493-1
Ubuntu:22.04:LTSlinux-azure5.15.0-1116.125UBUNTU-CVE-2023-53673
Ubuntu:22.04:LTSlinux-azure-5.19no fix listedUBUNTU-CVE-2023-53673
Ubuntu:24.04:LTSlinux-azure-6.11no fix listedUBUNTU-CVE-2023-53673
Ubuntu:22.04:LTSlinux-azure-6.2no fix listedUBUNTU-CVE-2023-53673
Ubuntu:22.04:LTSlinux-azure-6.5no fix listedUBUNTU-CVE-2023-53673
Ubuntu:22.04:LTSlinux-azure-fde5.15.0-1116.125UBUNTU-CVE-2023-53673
Ubuntu:22.04:LTSlinux-azure-fde-5.19no fix listedUBUNTU-CVE-2023-53673
Ubuntu:22.04:LTSlinux-azure-fde-6.2no fix listedUBUNTU-CVE-2023-53673
Ubuntu:22.04:LTSlinux-gcp5.15.0-1111.121UBUNTU-CVE-2023-53673
Ubuntu:22.04:LTSlinux-gcp5.15.0-1111.121USN-8493-1
Ubuntu:22.04:LTSlinux-gcp-5.19no fix listedUBUNTU-CVE-2023-53673
Ubuntu:24.04:LTSlinux-gcp-6.11no fix listedUBUNTU-CVE-2023-53673
Ubuntu:22.04:LTSlinux-gcp-6.2no fix listedUBUNTU-CVE-2023-53673
Ubuntu:22.04:LTSlinux-gcp-6.5no fix listedUBUNTU-CVE-2023-53673
Ubuntu:22.04:LTSlinux-gke5.15.0-1107.113UBUNTU-CVE-2023-53673
Ubuntu:22.04:LTSlinux-gke5.15.0-1107.113USN-8493-1
Ubuntu:22.04:LTSlinux-gkeop5.15.0-1094.102USN-8493-1
Ubuntu:22.04:LTSlinux-gkeop5.15.0-1094.102UBUNTU-CVE-2023-53673
Ubuntu:22.04:LTSlinux-hwe-5.19no fix listedUBUNTU-CVE-2023-53673
Ubuntu:24.04:LTSlinux-hwe-6.11no fix listedUBUNTU-CVE-2023-53673
Ubuntu:22.04:LTSlinux-hwe-6.2no fix listedUBUNTU-CVE-2023-53673
Ubuntu:22.04:LTSlinux-hwe-6.5no fix listedUBUNTU-CVE-2023-53673
Ubuntu:22.04:LTSlinux-ibm5.15.0-1105.109UBUNTU-CVE-2023-53673
Ubuntu:22.04:LTSlinux-ibm5.15.0-1105.109USN-8493-1
Ubuntu:24.04:LTSlinux-intelno fix listedUBUNTU-CVE-2023-53673
Ubuntu:22.04:LTSlinux-intel-iot-realtimeno fix listedUBUNTU-CVE-2023-53673
Ubuntu:22.04:LTSlinux-intel-iotg5.15.0-1106.112UBUNTU-CVE-2023-53673
Ubuntu:22.04:LTSlinux-intel-iotg5.15.0-1106.112USN-8493-1
Ubuntu:22.04:LTSlinux-kvm5.15.0-1103.108USN-8493-1
Ubuntu:22.04:LTSlinux-kvm5.15.0-1103.108UBUNTU-CVE-2023-53673
Ubuntu:22.04:LTSlinux-lowlatency5.15.0-183.193USN-8493-1
Ubuntu:22.04:LTSlinux-lowlatency5.15.0-183.193UBUNTU-CVE-2023-53673
Ubuntu:22.04:LTSlinux-lowlatency-hwe-5.19no fix listedUBUNTU-CVE-2023-53673
Ubuntu:24.04:LTSlinux-lowlatency-hwe-6.11no fix listedUBUNTU-CVE-2023-53673
Ubuntu:22.04:LTSlinux-lowlatency-hwe-6.2no fix listedUBUNTU-CVE-2023-53673
Ubuntu:22.04:LTSlinux-lowlatency-hwe-6.5no fix listedUBUNTU-CVE-2023-53673
Ubuntu:22.04:LTSlinux-nvidia5.15.0-1106.107USN-8493-1
Ubuntu:22.04:LTSlinux-nvidia5.15.0-1106.107UBUNTU-CVE-2023-53673
Ubuntu:22.04:LTSlinux-nvidia-6.2no fix listedUBUNTU-CVE-2023-53673
Ubuntu:22.04:LTSlinux-nvidia-6.5no fix listedUBUNTU-CVE-2023-53673
Ubuntu:22.04:LTSlinux-nvidia-tegra5.15.0-1063.63UBUNTU-CVE-2023-53673
Ubuntu:22.04:LTSlinux-nvidia-tegra5.15.0-1063.63USN-8493-1
Ubuntu:22.04:LTSlinux-nvidia-tegra-igx5.15.0-1052.52USN-8493-1
Ubuntu:22.04:LTSlinux-nvidia-tegra-igx5.15.0-1052.52UBUNTU-CVE-2023-53673
Ubuntu:22.04:LTSlinux-oem-5.17no fix listedUBUNTU-CVE-2023-53673
Ubuntu:22.04:LTSlinux-oem-6.0no fix listedUBUNTU-CVE-2023-53673
Ubuntu:22.04:LTSlinux-oem-6.1no fix listedUBUNTU-CVE-2023-53673
Ubuntu:24.04:LTSlinux-oem-6.11no fix listedUBUNTU-CVE-2023-53673
Ubuntu:22.04:LTSlinux-oem-6.5no fix listedUBUNTU-CVE-2023-53673
Ubuntu:24.04:LTSlinux-oem-6.8no fix listedUBUNTU-CVE-2023-53673
Ubuntu:22.04:LTSlinux-oracle5.15.0-1108.114USN-8493-1
Ubuntu:22.04:LTSlinux-oracle5.15.0-1108.114UBUNTU-CVE-2023-53673
Ubuntu:22.04:LTSlinux-oracle-6.5no fix listedUBUNTU-CVE-2023-53673
Ubuntu:22.04:LTSlinux-raspi5.15.0-1105.108USN-8527-1
Ubuntu:22.04:LTSlinux-raspi5.15.0-1105.108UBUNTU-CVE-2023-53673
Ubuntu:24.04:LTSlinux-raspi-realtimeno fix listedUBUNTU-CVE-2023-53673
Ubuntu:22.04:LTSlinux-realtimeno fix listedUBUNTU-CVE-2023-53673
Ubuntu:24.04:LTSlinux-realtimeno fix listedUBUNTU-CVE-2023-53673
Ubuntu:22.04:LTSlinux-riscvno fix listedUBUNTU-CVE-2023-53673
Ubuntu:24.04:LTSlinux-riscvno fix listedUBUNTU-CVE-2023-53673
Ubuntu:22.04:LTSlinux-riscv-5.19no fix listedUBUNTU-CVE-2023-53673
Ubuntu:22.04:LTSlinux-riscv-6.5no fix listedUBUNTU-CVE-2023-53673
Ubuntu:22.04:LTSlinux-starfive-5.19no fix listedUBUNTU-CVE-2023-53673
Ubuntu:22.04:LTSlinux-starfive-6.2no fix listedUBUNTU-CVE-2023-53673
Ubuntu:22.04:LTSlinux-starfive-6.5no fix listedUBUNTU-CVE-2023-53673
Ubuntu:22.04:LTSlinux-xilinx-zynqmp5.15.0-1074.78USN-8528-1
Ubuntu:22.04:LTSlinux-xilinx-zynqmp5.15.0-1074.78UBUNTU-CVE-2023-53673

Affected products (as reported)

VendorProductVersions
Linux Linux b8d290525e3972b5e876b2649a42bf4081d753fe – before 1ecf6dc2676ead4b927c50b1be0851fa4d756574b8d290525e3972b5e876b2649a42bf4081d753fe – before 59bd1e476bbc7bc6dff3c61bba787095a4839796b8d290525e3972b5e876b2649a42bf4081d753fe – before 093a07052406b363b1b2ab489e17dbadaf3e509bb8d290525e3972b5e876b2649a42bf4081d753fe – before 7f7cfcb6f0825652973b780f248603e23f16ee90
Linux Linux 5.7

References