Local privilege escalation via unsafe NMI trylock
Published Sep 16, 2026 · Updated Sep 16, 2026
Linux 6.15 allows local users to crash the kernel or escalate privileges through BPF tracing in NMI context on non-SMP builds. In __free_frozen_pages, non-PCP and isolated-migration paths can reach spin_trylock without the can_spin_trylock guard; on UP builds, that operation succeeds even when the interrupted context holds the zone lock. Exploitation requires a qualifying kernel build and BPF-driven page freeing from NMI context, where reentry can corrupt allocator freelists and interrupt service.
Summary
What happened
Linux 6.15 allows local users to crash the kernel or escalate privileges through BPF tracing in NMI context on non-SMP builds. In __free_frozen_pages, non-PCP and isolated-migration paths can reach spin_trylock without the can_spin_trylock guard; on UP builds, that operation succeeds even when the interrupted context holds the zone lock. Exploitation requires a qualifying kernel build and BPF-driven page freeing from NMI context, where reentry can corrupt allocator freelists and interrupt service.
The record
- CVE
- CVE-2026-90046
- Published
- Sep 16, 2026
- Updated
- Sep 16, 2026
- Vendor
- The Linux Kernel Organization
- Product
- Linux
- Classifications
- T1068
- Attack vector
- local
- Privileges
- authenticated
Timeline
How it unfolded
- Sep 16, 2026CVE publishedPublication date reported by the CVE source.
- Sep 16, 2026Record updatedLatest update available in the CVE record.
Exploitability
Present is not the same as exploitable
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Is a vulnerable build present?
Compare these published version ranges with your installed build and any vendor patches.
- Affected versionversion=6.15
- Affected versionversion=8c57b687e8331eb80e302a2c528b18b966a9ac7a <06c76d3c389ff504052f64b1acee44651bd847fa
- Affected versionversion=8c57b687e8331eb80e302a2c528b18b966a9ac7a <3105ae628fb785d48b49256468be4f21a7b3cfc0
- Affected versionversion=8c57b687e8331eb80e302a2c528b18b966a9ac7a <68a069b407303e71db371df85036101e8ff59280
What conditions does exploitation require?
What is affected?
Published CVSS scores
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Attacks
What attackers are doing with it
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Weakness, pattern, technique
Public exploit references
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Technologies
Your stack
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Your stack
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