sched_ext: Don't BUG_ON a destroyed DSQ in process_deferred_reenq_users (CVE-2026-89516) | HOL Guard CVE

Unknown severity · Source severity not reportedCVE-2026-89516

sched_ext: Don't BUG_ON a destroyed DSQ in process_deferred_reenq_users

Answer in brief

CVE-2026-89516 records a Unknown severity vulnerability in sched_ext: Don't BUG_ON a destroyed DSQ in process_deferred_reenq_users. The current sources do not mark it as known exploited. The current feed maps Linux/Linux (generic), Linux/Linux (generic). Check affected ranges and fixed versions before updating.

Analysis pending evidence review

HOL Guard separates source facts from reviewed analysis. See the methodology.

Published Sep 11, 2026Updated Sep 11, 2026Source checked Sep 11, 2026First seen by HOL Sep 11, 2026Material review Sep 11, 2026

Upstream Advisory

Key facts

Risk: Unknown severitySource severity not reported
Exploitation: Not marked as known exploited
Affected software: 2 mapped packages or products
Fix availability: Available

Why this deserves its current priority

A CVSS score is not reported in the current record. The current sources do not mark it as known exploited. Treat this as a source-backed prioritization signal, not a statement about your environment.

Analysis status

Analysis pending evidence review

Factual feed record only; HOL analysis is not approved for indexing. Read the methodology.

Affected scope and exposure questions

The current feed maps Linux/Linux (generic), Linux/Linux (generic). Check affected ranges and fixed versions before updating.

Mapped affected packages and fixed versions
Package	Affected range	Fixed version
Linux/Linuxgeneric	>=84b1a0ea0b7c23dec240783a592e480780efe459 <c480961a1e790b46ffd8c20c4b6754d65ec6572d \|\| >=84b1a0ea0b7c23dec240783a592e480780efe459 <8d8dd8ae89eaa78b37fc85528e926029f5facbdf	c480961a1e790b46ffd8c20c4b6754d65ec6572d, 8d8dd8ae89eaa78b37fc85528e926029f5facbdf
Linux/Linuxgeneric	7.1	Not reported

Recommended response

Check inventory. Check lockfiles and deployed manifests for Linux/Linux, Linux/Linux.
Review the reported fix. Update Linux/Linux to c480961a1e790b46ffd8c20c4b6754d65ec6572d if you use the affected versions. Test the change in a non-production environment first.

Evidence timeline and material changes

Published upstream
Sep 11, 2026
Evidence: source:cvelist:source_dates:source-dates:record
Source modified
Sep 11, 2026
Evidence: source:cvelist:source_dates:source-dates:record
First seen by HOL
Sep 11, 2026

Sources and claim methodology

Upstream source 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.

Quoted source text, attributed separately from HOL analysis.