---
id: CVE-2026-90254
title: >-
  In the Linux kernel, the following vulnerability has been resolved:


  Bluetooth: hci_sync: free the advertising instance on the failure and cancel
  paths


  adv_timeout_expire() hands a kmalloc()ed instance byte to

  hci_cmd_sync_queue() with …
summary: >-
  In the Linux kernel, the following vulnerability has been resolved:


  Bluetooth: hci_sync: free the advertising instance on the failure and cancel
  paths


  adv_timeout_expire() hands a kmalloc()ed instance byte to

  hci_cmd_sync_queue() with …
severity: medium
vendor: Linux
product: Linux
affected:
  - >-
    Linux >= c249ea9b4309cf3250c5bbb42a05d38d0ed9071c <
    c2019224a766245b7db39d87fdfe84c3fdc879d9
  - >-
    Linux >= c249ea9b4309cf3250c5bbb42a05d38d0ed9071c <
    193182c6467f508a8a61d5db506d796ffed6eee6
  - >-
    Linux >= c249ea9b4309cf3250c5bbb42a05d38d0ed9071c <
    2e3d827cd56865c14f6ca118bbccd7801091fb21
  - >-
    Linux >= c249ea9b4309cf3250c5bbb42a05d38d0ed9071c <
    9c3b6c1413bd0b4993642d987616331f84d9b7f5
  - >-
    Linux >= c249ea9b4309cf3250c5bbb42a05d38d0ed9071c <
    bb5ca1cc7744c41c59002bd6523714a685ae6595
  - >-
    Linux >= c249ea9b4309cf3250c5bbb42a05d38d0ed9071c <
    120d8dc042e3d45073bb6e50ee7b058a0b182627
  - Linux 6.1
published: '2026-09-17'
updated: '2026-09-17'
sourceUpdated: '2026-09-17T17:17:21.730'
source: NVD
sourceUrl: 'https://nvd.nist.gov/vuln/detail/CVE-2026-90254'
references:
  - url: 'https://git.kernel.org/stable/c/120d8dc042e3d45073bb6e50ee7b058a0b182627'
    label: 416baaa9-dc9f-4396-8d5f-8c081fb06d67
  - url: 'https://git.kernel.org/stable/c/193182c6467f508a8a61d5db506d796ffed6eee6'
    label: 416baaa9-dc9f-4396-8d5f-8c081fb06d67
  - url: 'https://git.kernel.org/stable/c/2e3d827cd56865c14f6ca118bbccd7801091fb21'
    label: 416baaa9-dc9f-4396-8d5f-8c081fb06d67
  - url: 'https://git.kernel.org/stable/c/9c3b6c1413bd0b4993642d987616331f84d9b7f5'
    label: 416baaa9-dc9f-4396-8d5f-8c081fb06d67
  - url: 'https://git.kernel.org/stable/c/bb5ca1cc7744c41c59002bd6523714a685ae6595'
    label: 416baaa9-dc9f-4396-8d5f-8c081fb06d67
  - url: 'https://git.kernel.org/stable/c/c2019224a766245b7db39d87fdfe84c3fdc879d9'
    label: 416baaa9-dc9f-4396-8d5f-8c081fb06d67
  - url: >-
      https://security.access.redhat.com/data/csaf/v2/vex/2026/cve-2026-90254.json
  - url: 'https://access.redhat.com/security/cve/CVE-2026-90254'
  - url: 'https://bugzilla.redhat.com/show_bug.cgi?id=2536160'
  - url: 'https://www.cve.org/CVERecord?id=CVE-2026-90254'
  - url: 'https://nvd.nist.gov/vuln/detail/CVE-2026-90254'
  - url: >-
      https://git.kernel.org/pub/scm/linux/security/vulns.git/plain/cve/published/2026/CVE-2026-90254.mbox
tags:
  - nvd
  - cve.org
  - csaf
  - vex
  - red-hat
ingestedAt: '2026-09-17T16:21:47.843Z'
epss: 0.00206
epssPercentile: 0.10514
cvss: 5.5
cvssVector: 'CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:H'
cvssSource: vendor
cwe:
  - CWE-772
---

## Overview

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

Bluetooth: hci_sync: free the advertising instance on the failure and cancel paths

adv_timeout_expire() hands a kmalloc()ed instance byte to
hci_cmd_sync_queue() with a NULL destroy callback, and only
adv_timeout_expire_sync() frees it. That leaks on two paths:

 - the return value is not checked, and hci_cmd_sync_queue() does not
   take ownership when it fails (-ENETDOWN, -ENODEV, -ENOMEM);

 - a cancelled entry is not released, as _hci_cmd_sync_cancel_entry()
   does not free entry->data when there is no destroy callback.
   hci_cmd_sync_clear() cancels every pending entry when the controller
   is unregistered.

Free the buffer from a destroy callback, and in the caller when the entry
could not be queued at all.

## Remediation

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

## Vendor advisories

- **Red Hat VEX** · Low · affected: Red Hat Enterprise Linux 10, Red Hat Enterprise Linux 9, Red Hat OpenShift Container Platform 4 · no fix planned: Red Hat Enterprise Linux 10, Red Hat Enterprise Linux 9, Red Hat OpenShift Container Platform 4 · updated 2026-10-05 · [vex](https://security.access.redhat.com/data/csaf/v2/vex/2026/cve-2026-90254.json)