CVE-2026-89516: Linux kernel · sched_ext: Don't BUG_ON a destroyed DSQ in process_deferred_reenq_users
Affects Linux kernelSource GCVE Database
Not known to be exploited.
Data as of 12 Nov 2026, 20:26 UTC
Rated by Threat Radar · CVSS not yet scored by NVD
Exploitation evidence
Disclosed: evidence found.
CVE published 11 Sep 2026
Detectable: no evidence on record.
No public nuclei template indexed
Weaponized: no evidence on record.
No public exploit code indexed in Metasploit or Exploit-DB
Exploited in the wildExploited: no evidence on record.
Not in CISA KEV and no source reports exploitation
Observed by OffSeq MirageSeen by Mirage: no evidence on record.
No attack traffic recorded by OffSeq Mirage sensors
A missing step is not evidence of safety. Sources: cve.org (opens in a new tab), the Metasploit, Exploit-DB and nuclei-templates index as of 12 Nov 2026.
What to do
Affected software
| Product | Affected | Fixed in |
|---|---|---|
Ubuntu 24.04 LTSlinux-aws-6.14pkg:deb/ubuntu/linux-aws-6.14?arch=source&distro=nobleOther threats | Affected
| Fixed in– |
Ubuntu 24.04 LTSlinux-aws-6.17pkg:deb/ubuntu/linux-aws-6.17?arch=source&distro=nobleOther threats | Affected
| Fixed in– |
Ubuntu 24.04 LTSlinux-azure-6.11pkg:deb/ubuntu/linux-azure-6.11?arch=source&distro=nobleOther threats | Affected
| Fixed in– |
Ubuntu 24.04 LTSlinux-azure-6.14pkg:deb/ubuntu/linux-azure-6.14?arch=source&distro=nobleOther threats | Affected
| Fixed in– |
Ubuntu 24.04 LTSlinux-azure-6.17pkg:deb/ubuntu/linux-azure-6.17?arch=source&distro=nobleOther threats | Affected
| Fixed in– |
Ubuntu 24.04 LTSlinux-azure-fde-6.14pkg:deb/ubuntu/linux-azure-fde-6.14?arch=source&distro=nobleOther threats | Affected
| Fixed in– |
Check your own hosts for these packages with threat-finder (opens in a new tab), our free open-source scanner.
AI-suggested
A fix has been implemented to address this issue by reading the DSQ ID atomically and avoiding the BUG_ON when the DSQ is invalid. Users should apply the updated kernel versions that include this fix. No additional mitigation steps are indicated.
Description
A vulnerability in the Linux kernel scheduler extension (sched_ext) could cause a BUG_ON condition when a destroyed deferred scheduling queue (DSQ) is accessed in process_deferred_reenq_users. This occurs because the code does not properly handle the case where the DSQ is destroyed before a deferred reenqueue operation runs, leading to a kernel BUG. The issue has been resolved by ensuring the DSQ ID is read atomically and skipping the BUG_ON if the DSQ is invalid.
References
- ubuntu.com/security/CVE-2026-89516 (opens in a new tab)
- cve.org/CVERecord?id=CVE-2026-89516 (opens in a new tab)
- git.kernel.org/linus/8d8dd8ae89eaa78b37fc85528e926029f5facbdf (opens in a new tab)
- git.kernel.org/stable/c/8d8dd8ae89eaa78b37fc85528e926029f5facbdf (opens in a new tab)
- git.kernel.org/stable/c/c480961a1e790b46ffd8c20c4b6754d65ec6572d (opens in a new tab)