Service interruption via unlocked lm90 alert update
Published Jul 24, 2026 · Updated Jul 24, 2026
Missing synchronization in the Linux kernel lm90 driver in affected releases starting with 5.3 allows local users to interrupt service. lm90_alert calls lm90_update_confreg without hwmon_lock, so a concurrent sysfs write restores stale data->config and re-enables the alert line. A low-privilege local user must race a sysfs write with an SMBus alert while an alarm remains active, producing an interrupt storm that degrades host availability.
Summary
What happened
Missing synchronization in the Linux kernel lm90 driver in affected releases starting with 5.3 allows local users to interrupt service. lm90_alert calls lm90_update_confreg without hwmon_lock, so a concurrent sysfs write restores stale data->config and re-enables the alert line. A low-privilege local user must race a sysfs write with an SMBus alert while an alarm remains active, producing an interrupt storm that degrades host availability.
The record
- CVE
- CVE-2026-64213
- Published
- Jul 24, 2026
- Updated
- Jul 24, 2026
- Vendor
- The Linux Kernel Organization
- Product
- Linux Kernel
- Classifications
- CWE-820, T1499.004
- Attack vector
- local
- Privileges
- authenticated
Timeline
How it unfolded
- Jul 24, 2026CVE publishedPublication date reported by the CVE source.
- Jul 24, 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=5.3
- Affected versionversion=7a1d220ccb0cc2b808eb176fb05bf55a38179f3f <873e919e3101063a7a75989510ccfc125a4391cf
- Affected versionversion=7a1d220ccb0cc2b808eb176fb05bf55a38179f3f <b0b66aae8a94c3663d47e4000b0e81b89ce32186
- Affected versionversion=7a1d220ccb0cc2b808eb176fb05bf55a38179f3f <bed1fc32e0eb653806fa98afcf55f9a311fc4ce2
What conditions does exploitation require?
What is affected?
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
No public exploit references are available in this record.
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Technologies
Your stack
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Your stack
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