Privileged race during filesystem thread teardown
Published Sep 16, 2026 · Updated Sep 16, 2026
Race condition in Linux 7.0 allows local users with CAP_SYS_NICE to trigger unspecified impact through an f2fs sysfs write. The critical_task_priority store updates checkpoint or garbage-collection kthread scheduling state without holding s_umount, allowing it to race remount or teardown while those threads stop. Exploitation requires a mounted f2fs filesystem and CAP_SYS_NICE; the Linux CNA record does not publish a more specific consequence.
Summary
What happened
Race condition in Linux 7.0 allows local users with CAP_SYS_NICE to trigger unspecified impact through an f2fs sysfs write. The critical_task_priority store updates checkpoint or garbage-collection kthread scheduling state without holding s_umount, allowing it to race remount or teardown while those threads stop. Exploitation requires a mounted f2fs filesystem and CAP_SYS_NICE; the Linux CNA record does not publish a more specific consequence.
The record
- CVE
- CVE-2026-89831
- Published
- Sep 16, 2026
- Updated
- Sep 16, 2026
- Vendor
- The Linux Kernel Organization
- Product
- Linux
- Classifications
- Unavailable
- Attack vector
- local
- Privileges
- admin
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=52190933c37a96164b271f3f30c16099d9eb8c09 <8e4692c6c165e81b2cbb847d8da4b45a53483b33
- Affected versionversion=52190933c37a96164b271f3f30c16099d9eb8c09 <bee6dfcc111b1dffdb3e13d73b7028b699fa0165
- Affected versionversion=7.0
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
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Public exploit references
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Technologies
Your stack
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Your stack
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