Medium [CVE-2026-64038] (lm90) Stop work before releasing hwmon device
This medium-severity Red Hat Linux advisory covers CVE-2026-64038 affecting Red Hat Enterprise Linux 10, Red Hat Enterprise Linux 6, Red Hat package: kernel.
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Summary
In the Linux kernel, the following vulnerability has been resolved: hwmon: (lm90) Stop work before releasing hwmon device Sashiko reports: In lm90_probe(), the devm action to cancel the alert_work and report_work (lm90_restore_conf) is registered in lm90_init_client() before devm_hwmon_device_register_with_info() is called.
Because devm executes cleanup actions in reverse order during module unbind or probe failure, the hwmon device is unregistered and freed first. If lm90_alert_work() or lm90_report_alarms() runs in the window between the hwmon device being freed and the delayed works being cancelled, lm90_update_alarms() will dereference the freed data->hwmon_dev here.
Fix the problem by canceling the workers separately after registering the hwmon device and before registering the interrupt handler. This ensures that the workers are canceled after interrupts are disabled and before the hwmon device is released.
Add "shutdown" flag to indicate that device shutdown is in progress to prevent workers from being re-armed. A flaw was found in the Linux kernel's hardware monitoring (hwmon) subsystem.
A timing issue in the lm90 driver can cause the system to attempt to access freed memory during module cleanup. This use-after-free vulnerability could lead to system instability and a Denial of Service (DoS).
Affected versions
No affected-version range was extracted from the source record. The vendor advisory is authoritative — check it before change work.
Official advisory · medium-confidence parse· fetched 6 days ago·verify at source
Fixed versions
No fixed release is recorded yet. That does not prove no patch exists — confirm against the vendor advisory.
Official advisory · medium-confidence parse· fetched 6 days ago·verify at source
Mitigation
The source record does not include mitigation steps. That is not a statement that no fix exists — read the vendor advisory below for the authoritative guidance.
Official advisory · medium-confidence parse· fetched 6 days ago·verify at source
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