---
id: CVE-2026-89516
title: >-
  kernel: sched_ext: Don't BUG_ON a destroyed DSQ in
  process_deferred_reenq_users (CVE-2026-89516)
summary: >-
  A flaw was found in the Linux kernel's `sched_ext` component. When a Deferred
  Scheduling Queue (DSQ) is destroyed, a pending deferred re-enqueue (DRU)
  operation might still attempt to access the destroyed DSQ. This can lead to a
  `BUG_ON` c…
severity: medium
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-825
vendor: Red Hat
product: Red Hat OpenShift Container Platform 4
affected:
  - openshift_container_platform 4
published: '2026-09-11'
updated: '2026-09-18'
sourceUpdated: '2026-09-18T21:34:35+00:00'
source: CSAF
sourceUrl: 'https://security.access.redhat.com/data/csaf/v2/vex/2026/cve-2026-89516.json'
references:
  - url: >-
      https://security.access.redhat.com/data/csaf/v2/vex/2026/cve-2026-89516.json
  - url: 'https://access.redhat.com/security/cve/CVE-2026-89516'
  - url: 'https://bugzilla.redhat.com/show_bug.cgi?id=2532093'
  - url: 'https://www.cve.org/CVERecord?id=CVE-2026-89516'
  - url: 'https://nvd.nist.gov/vuln/detail/CVE-2026-89516'
  - url: >-
      https://git.kernel.org/pub/scm/linux/security/vulns.git/plain/cve/published/2026/CVE-2026-89516.mbox
  - url: 'https://git.kernel.org/stable/c/c480961a1e790b46ffd8c20c4b6754d65ec6572d'
  - url: 'https://git.kernel.org/stable/c/8d8dd8ae89eaa78b37fc85528e926029f5facbdf'
tags:
  - csaf
  - vex
  - red-hat
  - cve.org
epss: 0.00198
epssPercentile: 0.08502
ingestedAt: '2026-09-14T11:11:19.887Z'
---

## Overview

A flaw was found in the Linux kernel's `sched_ext` component. When a Deferred Scheduling Queue (DSQ) is destroyed, a pending deferred re-enqueue (DRU) operation might still attempt to access the destroyed DSQ. This can lead to a `BUG_ON` condition, causing a kernel panic and resulting in a Denial of Service (DoS) for the system.

## Vendor advisories

- **Red Hat VEX** · Moderate · updated 2026-09-18 · [vex](https://security.access.redhat.com/data/csaf/v2/vex/2026/cve-2026-89516.json)

**kernel: sched_ext: Don't BUG_ON a destroyed DSQ in process_deferred_reenq_users** — rated Moderate by Red Hat. Released 2026-09-11, updated 2026-09-18.

Not affected:

- Red Hat Enterprise Linux 10
- Red Hat Enterprise Linux 6
- Red Hat Enterprise Linux 7
- Red Hat Enterprise Linux 8
- Red Hat Enterprise Linux 9
- Red Hat OpenShift Container Platform 4

## Remediation

Refer to the advisory for fix availability.