Inconsistent trace reads via subbuffer resize race
Published Sep 11, 2026 · Updated Sep 11, 2026
Race condition in the Linux kernel trace ring buffer allows local users to trigger inconsistent reads during concurrent subbuffer resizing. ring_buffer_read_page() and ring_buffer_read_start() read trace_buffer::subbuf_size without locking while ring_buffer_subbuf_order_set() can change it, so readers calculate capacity from stale size state. Only local users permitted to read and resize tracefs buffers can reach the race; the published record specifies no impact beyond inconsistent trace-buffer reads.
Summary
What happened
Race condition in the Linux kernel trace ring buffer allows local users to trigger inconsistent reads during concurrent subbuffer resizing. ring_buffer_read_page() and ring_buffer_read_start() read trace_buffer::subbuf_size without locking while ring_buffer_subbuf_order_set() can change it, so readers calculate capacity from stale size state. Only local users permitted to read and resize tracefs buffers can reach the race; the published record specifies no impact beyond inconsistent trace-buffer reads.
The record
- CVE
- CVE-2026-89771
- Published
- Sep 11, 2026
- Updated
- Sep 11, 2026
- Vendor
- The Linux Kernel Organization
- Product
- Linux
- Classifications
- Unavailable
- 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
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=6.8
- Affected versionversion=f9b94daa542a8d2532f0930f01cd9aec2d19621b <0c7c517827a453128a8f58bfd849546a29813b27
- Affected versionversion=f9b94daa542a8d2532f0930f01cd9aec2d19621b <50f4a793c4ff24826efb0ac700989a5063cc53df
- Affected versionversion=f9b94daa542a8d2532f0930f01cd9aec2d19621b <6d666f0b8b36c0765cf19fbe6de5a7ba5a73aad9
- Affected versionversion=f9b94daa542a8d2532f0930f01cd9aec2d19621b <8a5f63637890f03177146efddaba5ec7a1b4d61f
What conditions does exploitation require?
What is affected?
Published CVSS scores
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Attacks
What attackers are doing with it
Daily unique IPs observed by Shadowserver honeypots for known exploited vulnerabilities (KEVs). Missing observations do not establish an absence of attacks.
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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