---
id: CVE-2026-90091
title: |-
  In the Linux kernel, the following vulnerability has been resolved:

  Bluetooth: L2CAP: fix race l2cap_sock_cleanup_listen() vs
summary: |-
  In the Linux kernel, the following vulnerability has been resolved:

  Bluetooth: L2CAP: fix race l2cap_sock_cleanup_listen() vs. put_chan

  For L2CAP sockets without owning sk->sk_socket, reading
  l2cap_pi(sk)->chan may race against concurr…
severity: high
cvss: 8
cvssVector: 'CVSS:3.1/AV:A/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H'
vendor: Linux
product: Linux
affected:
  - >-
    Linux >= b39298044e5534612511a2ff5de03ba5f6e7a820 <
    827de6bd2865b22aaabd554540def3b8a33018ab
  - >-
    Linux >= 8c37e4338c801ebb8cee52436c01c41e009f6e87 <
    7c7ac736b50fa259ed1bdddc18d79523f07c0442
  - >-
    Linux >= 84e718b6a814edc84159361f9f454a4e92ae91ae <
    4f8c63fe0097c9f6ea34409f82f79b3894903d91
  - >-
    Linux >= 36da806f7fbaee56ad9e81859deec203f9728700 <
    61d5ddbd524c715b224cbe7e9f01da4e05098b19
  - >-
    Linux >= 6fef032af0092ed5ccb767239a9ac1bc38c08a40 <
    32a7bc6e93be36b37fe61f351d312d358195bd61
  - >-
    Linux >= 6fef032af0092ed5ccb767239a9ac1bc38c08a40 <
    66d6ef18548ae6d7dd452b84115fc82c0a73a4ea
  - Linux 733e76e74e406c1d1ddc7369420dd8a47f48bb8a
  - Linux >= 6.1.178 < 6.1.188
  - Linux >= 6.6.145 < 6.6.157
  - Linux >= 6.12.97 < 6.12.110
  - Linux >= 6.18.40 < 6.18.52
  - Linux >= 7.1.5 < 7.2
  - Linux 7.2
published: '2026-09-17'
updated: '2026-09-18'
sourceUpdated: '2026-09-18T18:17:41.277'
source: NVD
sourceUrl: 'https://nvd.nist.gov/vuln/detail/CVE-2026-90091'
references:
  - url: 'https://git.kernel.org/stable/c/32a7bc6e93be36b37fe61f351d312d358195bd61'
    label: 416baaa9-dc9f-4396-8d5f-8c081fb06d67
  - url: 'https://git.kernel.org/stable/c/4f8c63fe0097c9f6ea34409f82f79b3894903d91'
    label: 416baaa9-dc9f-4396-8d5f-8c081fb06d67
  - url: 'https://git.kernel.org/stable/c/61d5ddbd524c715b224cbe7e9f01da4e05098b19'
    label: 416baaa9-dc9f-4396-8d5f-8c081fb06d67
  - url: 'https://git.kernel.org/stable/c/66d6ef18548ae6d7dd452b84115fc82c0a73a4ea'
    label: 416baaa9-dc9f-4396-8d5f-8c081fb06d67
  - url: 'https://git.kernel.org/stable/c/7c7ac736b50fa259ed1bdddc18d79523f07c0442'
    label: 416baaa9-dc9f-4396-8d5f-8c081fb06d67
  - url: 'https://git.kernel.org/stable/c/827de6bd2865b22aaabd554540def3b8a33018ab'
    label: 416baaa9-dc9f-4396-8d5f-8c081fb06d67
tags:
  - nvd
  - cve.org
epss: 0.00415
epssPercentile: 0.33049
ingestedAt: '2026-09-17T16:21:47.892Z'
---

## Overview

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

Bluetooth: L2CAP: fix race l2cap_sock_cleanup_listen() vs. put_chan

For L2CAP sockets without owning sk->sk_socket, reading
l2cap_pi(sk)->chan may race against concurrent l2cap_sock_kill() ->
l2cap_sock_put_chan().  This excludes simultaneous proto_ops callbacks,
but access in l2cap_sock_cleanup_listen() has unsafe lockless read.

 [Task 1]                         [Task 2 (hdev->workqueue)]
 l2cap_sock_release(parent)       l2cap_disconn_cfm
   l2cap_sock_cleanup_listen        l2cap_conn_del
     bt_accept_dequeue                l2cap_chan_del
       lock_sock(sk)                    l2cap_sock_teardown_cb
       bt_accept_unlink
         bt_sk(sk)->parent = NULL
       release_sock(sk) ----------------> lock_sock(sk)
                                          parent = /* NULL */
     lock_sock(sk) <--------------------- release_sock(sk)
                                          sock_set_flag(sk, SOCK_ZAPPED)
                                      l2cap_sock_close_cb
                                        l2cap_sock_kill(sk)
                                          l2cap_sock_put_chan
     chan = READ l2cap_pi(sk)->chan         l2cap_pi(sk)->chan = NULL
     l2cap_chan_hold_unless_zero            l2cap_put_chan(chan)
       kref_get_unless_zero(&chan->ref)

Task 1 may observe NULL which causes null-ptr-deref.

Fix the race by taking lock_sock() in l2cap_sock_kill() to
synchronize with l2cap_sock_cleanup_listen().  hold_unless_zero() is not
needed here, l2cap_pi(sk)->chan owns reference if it is non-NULL.

Clarify code comments vs. locking.

## Remediation

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