Kernel crash via destroyed DSQ deferred reenqueue
Published Sep 11, 2026 · Updated Sep 11, 2026
Race condition in sched_ext in Linux kernel 7.1 allows attackers to crash the kernel through a destroyed dispatch queue. process_deferred_reenq_users reads a DSQ invalidated by destroy_dsq and reaches BUG_ON because pending deferred reenqueue work is not flushed. Triggering the path requires sched_ext to be enabled and a BPF scheduler to queue a deferred reenqueue, destroy its DSQ, and reach run_deferred().
Summary
What happened
Race condition in sched_ext in Linux kernel 7.1 allows attackers to crash the kernel through a destroyed dispatch queue. process_deferred_reenq_users reads a DSQ invalidated by destroy_dsq and reaches BUG_ON because pending deferred reenqueue work is not flushed. Triggering the path requires sched_ext to be enabled and a BPF scheduler to queue a deferred reenqueue, destroy its DSQ, and reach run_deferred().
The record
- CVE
- CVE-2026-89516
- Published
- Sep 11, 2026
- Updated
- Sep 11, 2026
- Vendor
- The Linux Kernel Organization
- Product
- Linux
- Classifications
- T1499.004
- Attack vector
- local
- Privileges
- Unavailable
Timeline
How it unfolded
- Sep 11, 2026CVE publishedPublication date reported by the CVE source.
- Sep 11, 2026Record updatedLatest update available in the CVE record.
Exploitability
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Is a vulnerable build present?
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- Affected versionversion=7.1
- Affected versionversion=84b1a0ea0b7c23dec240783a592e480780efe459 <8d8dd8ae89eaa78b37fc85528e926029f5facbdf
- Affected versionversion=84b1a0ea0b7c23dec240783a592e480780efe459 <c480961a1e790b46ffd8c20c4b6754d65ec6572d
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Attacks
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