CVE-2026-89516
sched_ext: Don't BUG_ON a destroyed DSQ in process_deferred_reenq_users
Description
In the Linux kernel, the following vulnerability has been resolved: sched_ext: Don't BUG_ON a destroyed DSQ in process_deferred_reenq_users scx_bpf_dsq_reenq() queues a deferred reenq (dru) that runs from run_deferred(), not ops.dispatch(). If the DSQ is destroyed before the dru runs, process_deferred_reenq_users() sees dsq->id == SCX_DSQ_INVALID and hits the BUG_ON. destroy_dsq() doesn't flush pending drus, so just skip. tj: Read dsq->id once with READ_ONCE(). Reading it separately in the INVALID check and the BUG_ON would leave a window where destroy_dsq() can invalidate the id between the two reads and still trigger the BUG_ON.
INFO
Published Date :
Sept. 11, 2026, 8:19 p.m.
Last Modified :
Sept. 11, 2026, 8:19 p.m.
Remotely Exploit :
No
Source :
416baaa9-dc9f-4396-8d5f-8c081fb06d67
Solution
- Update the Linux kernel to the patched version.
- Ensure destroy_dsq() flushes pending drus.
- Read dsq->id once using READ_ONCE().
References to Advisories, Solutions, and Tools
Here, you will find a curated list of external links that provide in-depth
information, practical solutions, and valuable tools related to
CVE-2026-89516.
| URL | Resource |
|---|---|
| https://git.kernel.org/stable/c/8d8dd8ae89eaa78b37fc85528e926029f5facbdf | |
| https://git.kernel.org/stable/c/c480961a1e790b46ffd8c20c4b6754d65ec6572d |
CWE - Common Weakness Enumeration
While CVE identifies
specific instances of vulnerabilities, CWE categorizes the common flaws or
weaknesses that can lead to vulnerabilities. CVE-2026-89516 is
associated with the following CWEs:
Common Attack Pattern Enumeration and Classification (CAPEC)
Common Attack Pattern Enumeration and Classification
(CAPEC)
stores attack patterns, which are descriptions of the common attributes and
approaches employed by adversaries to exploit the CVE-2026-89516
weaknesses.
We scan GitHub repositories to detect new proof-of-concept exploits. Following list is a collection of public exploits and proof-of-concepts, which have been published on GitHub (sorted by the most recently updated).
Results are limited to the first 15 repositories due to potential performance issues.
The following list is the news that have been mention
CVE-2026-89516 vulnerability anywhere in the article.
The following table lists the changes that have been made to the
CVE-2026-89516 vulnerability over time.
Vulnerability history details can be useful for understanding the evolution of a vulnerability, and for identifying the most recent changes that may impact the vulnerability's severity, exploitability, or other characteristics.
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New CVE Received by 416baaa9-dc9f-4396-8d5f-8c081fb06d67
Sep. 11, 2026
Action Type Old Value New Value Added Description In the Linux kernel, the following vulnerability has been resolved: sched_ext: Don't BUG_ON a destroyed DSQ in process_deferred_reenq_users scx_bpf_dsq_reenq() queues a deferred reenq (dru) that runs from run_deferred(), not ops.dispatch(). If the DSQ is destroyed before the dru runs, process_deferred_reenq_users() sees dsq->id == SCX_DSQ_INVALID and hits the BUG_ON. destroy_dsq() doesn't flush pending drus, so just skip. tj: Read dsq->id once with READ_ONCE(). Reading it separately in the INVALID check and the BUG_ON would leave a window where destroy_dsq() can invalidate the id between the two reads and still trigger the BUG_ON. Added Affected New affected value received. <a href="https://github.com/CVEProject/cvelistV5/blob/main/cves/2026/89xxx/CVE-2026-89516.json">CVE-2026-89516</a> Added Reference https://git.kernel.org/stable/c/8d8dd8ae89eaa78b37fc85528e926029f5facbdf Added Reference https://git.kernel.org/stable/c/c480961a1e790b46ffd8c20c4b6754d65ec6572d