---
id: CVE-2026-99015
title: 'Bluetooth: hci_sock: Serialize dead-device detachment'
summary: |-
  In the Linux kernel, the following vulnerability has been resolved:

  Bluetooth: hci_sock: Serialize dead-device detachment

  Rebinding an HCI socket after its controller is unregistered can race
  monitor control replay and crash the kernel…
severity: none
vendor: Linux
product: Linux
affected:
  - >-
    Linux >= e04480920d1eec9c061841399aa6f35b6f987d8b <
    37cef0c8fb537f40600910d2c2e5f2d5509305f3
  - >-
    Linux >= e04480920d1eec9c061841399aa6f35b6f987d8b <
    76f2e2665697340ac719e7ff1bf148dd014e55c1
  - >-
    Linux >= e04480920d1eec9c061841399aa6f35b6f987d8b <
    c3d2799877906d0c8392d96e14216cd82b020330
  - >-
    Linux >= e04480920d1eec9c061841399aa6f35b6f987d8b <
    e660a22402944f2615a16fde7129a3c497537329
  - >-
    Linux >= e04480920d1eec9c061841399aa6f35b6f987d8b <
    381a0925c556a8d91a80a9b9e3e86651d60ffee3
  - Linux d6ef8bb00aa65eceb413fc165a55086459863e38
  - Linux 0e77f979a97d3d517fad0b51249ba6fb8ae2d365
  - Linux 0782c8c7f80c9dd457acdfe16fd0f339f0e73093
  - Linux 3719acc161d5c1ce09912cc1c9eddc2c5faa3c66
  - Linux ff29fe26ab8679bc13a3f0bf5b2911535a1cfc35
  - Linux f2f856b65ac4b77049c76c0e89ecd3a177e9fcd1
  - Linux 75dd00b755ebfa9b24eaedc9f42e9adfc00ae00c
  - Linux >= 4.4.281 < 4.5
  - Linux >= 4.9.280 < 4.10
  - Linux >= 4.14.244 < 4.15
  - Linux >= 4.19.203 < 4.20
  - Linux >= 5.4.140 < 5.5
  - Linux >= 5.10.58 < 5.11
  - Linux >= 5.13.10 < 5.14
  - Linux 5.14
published: '2026-10-23'
updated: '2026-10-23'
sourceUpdated: '2026-10-23T12:20:41.608Z'
source: CVEORG
sourceUrl: 'https://www.cve.org/CVERecord?id=CVE-2026-99015'
references:
  - url: 'https://git.kernel.org/stable/c/37cef0c8fb537f40600910d2c2e5f2d5509305f3'
  - url: 'https://git.kernel.org/stable/c/76f2e2665697340ac719e7ff1bf148dd014e55c1'
  - url: 'https://git.kernel.org/stable/c/c3d2799877906d0c8392d96e14216cd82b020330'
  - url: 'https://git.kernel.org/stable/c/e660a22402944f2615a16fde7129a3c497537329'
  - url: 'https://git.kernel.org/stable/c/381a0925c556a8d91a80a9b9e3e86651d60ffee3'
tags:
  - cve.org
ingestedAt: '2026-10-23T13:24:55.540Z'
---

## Overview

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

Bluetooth: hci_sock: Serialize dead-device detachment

Rebinding an HCI socket after its controller is unregistered can race
monitor control replay and crash the kernel. hci_sock_bind() clears
hci_pi(sk)->hdev and drops the device reference under only the socket
lock, whereas send_monitor_control_replay() holds hci_sk_list.lock for
reading.

Replay can observe a non-NULL hdev, then bind can clear it and drop the
last reference before create_monitor_ctrl_open() reads hdev->id. This
can cause a NULL pointer dereference if the pointer is reloaded, or a
use-after-free if the old pointer is retained.

The kernel reported:

  KASAN: null-ptr-deref in range [0x0000000000000068-0x000000000000006f]
  RIP: 0010:create_monitor_ctrl_open+0x579/0x800
  Call Trace:
   hci_sock_bind+0xd96/0x1190
   __sys_bind+0x166/0x200
   __x64_sys_bind+0x6d/0xb0
   do_syscall_64+0xdd/0x4a0
   entry_SYSCALL_64_after_hwframe+0x77/0x7f

The same missing serialization lets hci_send_to_sock() select a socket
for the old device and queue its frame after bind has detached the socket
or installed a new binding.

Take hci_sk_list.lock for writing when clearing the device pointer and
resetting the socket state. This waits for existing replay and delivery
readers to finish before detachment and prevents later readers from
using the old binding. Keep hci_dev_put() outside the critical section
because the final device release can sleep.

## Affected

- `Linux >= e04480920d1eec9c061841399aa6f35b6f987d8b < 37cef0c8fb537f40600910d2c2e5f2d5509305f3`
- `Linux >= e04480920d1eec9c061841399aa6f35b6f987d8b < 76f2e2665697340ac719e7ff1bf148dd014e55c1`
- `Linux >= e04480920d1eec9c061841399aa6f35b6f987d8b < c3d2799877906d0c8392d96e14216cd82b020330`
- `Linux >= e04480920d1eec9c061841399aa6f35b6f987d8b < e660a22402944f2615a16fde7129a3c497537329`
- `Linux >= e04480920d1eec9c061841399aa6f35b6f987d8b < 381a0925c556a8d91a80a9b9e3e86651d60ffee3`
- `Linux d6ef8bb00aa65eceb413fc165a55086459863e38`
- `Linux 0e77f979a97d3d517fad0b51249ba6fb8ae2d365`
- `Linux 0782c8c7f80c9dd457acdfe16fd0f339f0e73093`
- `Linux 3719acc161d5c1ce09912cc1c9eddc2c5faa3c66`
- `Linux ff29fe26ab8679bc13a3f0bf5b2911535a1cfc35`
- `Linux f2f856b65ac4b77049c76c0e89ecd3a177e9fcd1`
- `Linux 75dd00b755ebfa9b24eaedc9f42e9adfc00ae00c`
- `Linux >= 4.4.281 < 4.5`
- `Linux >= 4.9.280 < 4.10`
- `Linux >= 4.14.244 < 4.15`
- `Linux >= 4.19.203 < 4.20`
- `Linux >= 5.4.140 < 5.5`
- `Linux >= 5.10.58 < 5.11`
- `Linux >= 5.13.10 < 5.14`
- `Linux 5.14`

## Remediation

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