---
id: CVE-2026-46111
title: 'Bluetooth: hci_conn: fix potential UAF in create_big_sync'
summary: |-
  In the Linux kernel, the following vulnerability has been resolved:

  Bluetooth: hci_conn: fix potential UAF in create_big_sync

  Add hci_conn_valid() check in create_big_sync() to detect stale
  connections before proceeding with BIG creati…
severity: high
cvss: 7.8
cvssVector: 'CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H'
cvssSource: cna
vendor: Linux
product: Linux
affected:
  - >-
    Linux >= eca0ae4aea66914515e5e3098ea051b518ee5316 <
    d41093723e47255d7d74df86e2736711c1b8486e
  - >-
    Linux >= eca0ae4aea66914515e5e3098ea051b518ee5316 <
    6823f730bf195fc296d9edd09e2ca94bc1ff5584
  - >-
    Linux >= eca0ae4aea66914515e5e3098ea051b518ee5316 <
    1750a2df0eab61dc421a7afae74abdd239a44b85
  - >-
    Linux >= eca0ae4aea66914515e5e3098ea051b518ee5316 <
    dc34f8d8240f25dd137dc2758ebbcc75e3779142
  - >-
    Linux >= eca0ae4aea66914515e5e3098ea051b518ee5316 <
    f8eaf92c57ad99358dd372580d5ff87623343a72
  - >-
    Linux >= eca0ae4aea66914515e5e3098ea051b518ee5316 <
    0beddb0c380bed5f5b8e61ddbe14635bb73d0b41
  - Linux 6.0
ssvc:
  exploitation: none
  automatable: 'no'
  technicalImpact: total
  timestamp: '2026-10-16T15:19:42.422242Z'
published: '2026-05-28'
updated: '2026-10-16'
sourceUpdated: '2026-10-16T15:20:51.197Z'
source: CVEORG
sourceUrl: 'https://www.cve.org/CVERecord?id=CVE-2026-46111'
references:
  - url: 'https://git.kernel.org/stable/c/d41093723e47255d7d74df86e2736711c1b8486e'
  - url: 'https://git.kernel.org/stable/c/6823f730bf195fc296d9edd09e2ca94bc1ff5584'
  - url: 'https://git.kernel.org/stable/c/1750a2df0eab61dc421a7afae74abdd239a44b85'
  - url: 'https://git.kernel.org/stable/c/dc34f8d8240f25dd137dc2758ebbcc75e3779142'
  - url: 'https://git.kernel.org/stable/c/f8eaf92c57ad99358dd372580d5ff87623343a72'
  - url: 'https://git.kernel.org/stable/c/0beddb0c380bed5f5b8e61ddbe14635bb73d0b41'
tags:
  - cve.org
epss: 0.00171
epssPercentile: 0.0604
ingestedAt: '2026-10-16T17:24:46.706Z'
---

## Overview

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

Bluetooth: hci_conn: fix potential UAF in create_big_sync

Add hci_conn_valid() check in create_big_sync() to detect stale
connections before proceeding with BIG creation. Handle the
resulting -ECANCELED in create_big_complete() and re-validate the
connection under hci_dev_lock() before dereferencing, matching the
pattern used by create_le_conn_complete() and create_pa_complete().

Keep the hci_conn object alive across the async boundary by taking
a reference via hci_conn_get() when queueing create_big_sync(), and
dropping it in the completion callback. The refcount and the lock
are complementary: the refcount keeps the object allocated, while
hci_dev_lock() serializes hci_conn_hash_del()'s list_del_rcu() on
hdev->conn_hash, as required by hci_conn_del().

hci_conn_put() is called outside hci_dev_unlock() so the final put
(which resolves to kfree() via bt_link_release) does not run under
hdev->lock, though the release path would be safe either way.

Without this, create_big_complete() would unconditionally
dereference the conn pointer on error, causing a use-after-free
via hci_connect_cfm() and hci_conn_del().

## Affected

- `Linux >= eca0ae4aea66914515e5e3098ea051b518ee5316 < d41093723e47255d7d74df86e2736711c1b8486e`
- `Linux >= eca0ae4aea66914515e5e3098ea051b518ee5316 < 6823f730bf195fc296d9edd09e2ca94bc1ff5584`
- `Linux >= eca0ae4aea66914515e5e3098ea051b518ee5316 < 1750a2df0eab61dc421a7afae74abdd239a44b85`
- `Linux >= eca0ae4aea66914515e5e3098ea051b518ee5316 < dc34f8d8240f25dd137dc2758ebbcc75e3779142`
- `Linux >= eca0ae4aea66914515e5e3098ea051b518ee5316 < f8eaf92c57ad99358dd372580d5ff87623343a72`
- `Linux >= eca0ae4aea66914515e5e3098ea051b518ee5316 < 0beddb0c380bed5f5b8e61ddbe14635bb73d0b41`
- `Linux 6.0`

## Remediation

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