---
id: CVE-2026-90256
title: |-
  In the Linux kernel, the following vulnerability has been resolved:

  Bluetooth: L2CAP: use proto_lock for l2cap_data to fix l2cap_disconn_ind

  hci_conn::l2cap_data is accessed without locks in l2cap_disconn_ind via
  hci_conn_timeout (disc…
summary: |-
  In the Linux kernel, the following vulnerability has been resolved:

  Bluetooth: L2CAP: use proto_lock for l2cap_data to fix l2cap_disconn_ind

  hci_conn::l2cap_data is accessed without locks in l2cap_disconn_ind via
  hci_conn_timeout (disc…
severity: high
cvss: 8.8
cvssVector: 'CVSS:3.1/AV:A/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H'
vendor: Linux
product: Linux
affected:
  - >-
    Linux >= ab4eedb790cae44313759b50fe47da285e2519d5 <
    b495a3a9b33bc4e4613e685bf5c96c136caa22d8
  - >-
    Linux >= ab4eedb790cae44313759b50fe47da285e2519d5 <
    2b66c83ff1751d6bd3201b3017206262ab46dc05
  - Linux efc30877bd4bc85fefe98d80af60fafc86e5775e
  - Linux f87271d21dd4ee83857ca11b94e7b4952749bbae
  - Linux 18ab6b6078fa8191ca30a3065d57bf35d5635761
  - Linux >= 6.6.84 < 6.7
  - Linux >= 6.12.20 < 6.13
  - Linux >= 6.13.8 < 6.14
  - Linux 6.14
published: '2026-09-17'
updated: '2026-09-18'
sourceUpdated: '2026-09-18T18:17:51.170'
source: NVD
sourceUrl: 'https://nvd.nist.gov/vuln/detail/CVE-2026-90256'
references:
  - url: 'https://git.kernel.org/stable/c/2b66c83ff1751d6bd3201b3017206262ab46dc05'
    label: 416baaa9-dc9f-4396-8d5f-8c081fb06d67
  - url: 'https://git.kernel.org/stable/c/b495a3a9b33bc4e4613e685bf5c96c136caa22d8'
    label: 416baaa9-dc9f-4396-8d5f-8c081fb06d67
tags:
  - nvd
  - cve.org
epss: 0.00289
epssPercentile: 0.21721
ingestedAt: '2026-09-17T16:21:47.842Z'
---

## Overview

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

Bluetooth: L2CAP: use proto_lock for l2cap_data to fix l2cap_disconn_ind

hci_conn::l2cap_data is accessed without locks in l2cap_disconn_ind via
hci_conn_timeout (disc_work) -> hci_proto_disconn_ind ->
l2cap_disconn_ind.  This is UAF if the l2cap_conn is deleted
concurrently.

disc_work is disabled sync in hci_conn_del(), so we cannot take
hci_dev_lock in disc_work.

Fix by using proto_lock to guard l2cap_data, in addition to hdev->lock
which is held in other access paths.

## Remediation

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