published August 15, 2026
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.