CVE-2026-74552: hwmon: (lm90) Only report alarms if driver is ready

Severity: unknown
Exploited in the wild: not listed in CISA KEV
EPSS: 0.2% probability of exploitation in the next 30 days
Public exploit or detection template: none known
Published: 2026-08-15 · updated 2026-08-19

Description

In the Linux kernel, the following vulnerability has been resolved: hwmon: (lm90) Only report alarms if driver is ready Userspace can read sysfs attributes before driver registration is complete, immediately after devm_hwmon_device_register_with_info() has been called. At that time, data->hwmon_dev is not yet initialized. This can trigger a NULL pointer access since lm90_update_device() and with it lm90_update_alarms_locked() will be called. This call schedules report_work and lm90_report_alarms(), which passes the still-NULL data->hwmon_dev to hwmon_notify_event() and triggers a NULL pointer dereference. Fix the problem by only scheduling the report and alert workers data->hwmon_dev is set.

Affected products

Linux kernel: 6.0 — fixed in 7.2

How to fix

Upgrade to a fixed version: Linux kernel 7.2. Check the vendor advisory for mitigations.

References

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