System hang via I2C adapter-removal race
Published Sep 16, 2026 · Updated Sep 16, 2026
A race in the Linux kernel I2C core allows local users to trigger a use-after-free and system hang during adapter removal. i2c_del_adapter leaves new_device writable after freeing adapter debugfs state, so a racing write reaches i2c_device_probe and reuses the freed parent. Reachability requires local write access to the adapter's new_device sysfs attribute while that adapter is being removed; a late client can also prevent teardown completion.
Summary
What happened
A race in the Linux kernel I2C core allows local users to trigger a use-after-free and system hang during adapter removal. i2c_del_adapter leaves new_device writable after freeing adapter debugfs state, so a racing write reaches i2c_device_probe and reuses the freed parent. Reachability requires local write access to the adapter's new_device sysfs attribute while that adapter is being removed; a late client can also prevent teardown completion.
The record
- CVE
- CVE-2026-89983
- Published
- Sep 16, 2026
- Updated
- Sep 16, 2026
- Vendor
- The Linux Kernel Organization
- Product
- Linux
- Classifications
- T1499.004
- Attack vector
- local
- Privileges
- Unavailable
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=0e8926abfd7aee220e44be5566affd7a8580b50e <dc33a9762538b3250ed6b5644a4d44c748be33a6
- Affected versionversion=4a2be5a72865bdd219b2d8c327b9fa03e87a4a9e <f9094ace03e0a532cc6505d2e97b61ae738da4ed
- Affected versionversion=5.15.168 <5.15.221
- Affected versionversion=6.1.113 <6.1.188
- Affected versionversion=6.6.55 <6.6.157
- Affected versionversion=6.8
- Affected versionversion=73febd775bdbdb98c81255ff85773ac410ded5c4 <112b3d48084c820bbccf41d9783fd122e3ac4cb0
- Affected versionversion=73febd775bdbdb98c81255ff85773ac410ded5c4 <552836be2d95c688eede6371f85532abe1a71232
- Affected versionversion=73febd775bdbdb98c81255ff85773ac410ded5c4 <643fb872aa04342d27dbef52b2b3cf3fe71b2c7b
- Affected versionversion=73febd775bdbdb98c81255ff85773ac410ded5c4 <b15b548d52b43ba8ac4652bc2c7244a8dd1e9622
- Affected versionversion=e2a268b0f512fb18ae5961b1fdfaf610ed6bd661 <1f1bcd4eca6caa3e4258d9a31925112539406eb6
What conditions does exploitation require?
What is affected?
Published CVSS scores
No CVSS assessment is available in this record.
CVSS describes severity. EPSS estimates exploitation probability.
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
Public exploit references
- syzbot C reproducer for I2C debugfs use-after-freeproof of concept · demonstrated
Labels summarize the accepted research assessment. They do not indicate a test against your environment.
Technologies
Your stack
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Your stack
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