CVE-2026-74552

A flaw was found in the Linux kernel's hwmon (lm90) driver. A local user can trigger a null pointer dereference by reading sysfs attributes before the driver's registration is complete. This can lead to a system crash, resulting in a denial of service.

A flaw of moderate impact was found in the Linux kernel hwmon (lm90) driver. Userspace can read sysfs attributes immediately after the hwmon device has been registered with devm_hwmon_device_register_with_info() but before driver initialization completes and data->hwmon_dev is set. Such a read calls lm90_update_device() and lm90_update_alarms_locked(), which schedules the report work; lm90_report_alarms() then passes the still-NULL data->hwmon_dev to hwmon_notify_event(), causing a NULL pointer dereference. A local user who can read these sysfs attributes during the short driver-registration window can therefore crash the kernel, resulting in a denial of service; there is no impact on confidentiality or integrity. Red Hat Enterprise Linux 10 and Red Hat In-Vehicle OS 2 (including the kernel-ivos-qualcomm builds) are affected. Because exploitation requires winning a timing-dependent race during driver probe and the impact is limited to availability, the fix is currently deferred to a future update of the affected releases; the residual risk is that a local user could trigger a kernel panic (denial of service). Red Hat Enterprise Linux 7, 8, and 9, including their real-time kernel variants, are not affected because the vulnerable code is not present in those kernels, and Red Hat Enterprise Linux 6 Extended Lifecycle Support is out of support scope.

The CVSS score(s) listed for this vulnerability do not reflect the associated product's status, and are included for informational purposes to better understand the severity of this vulnerability.

Mitigation for this issue is either not available or the currently available options do not meet the Red Hat Product Security criteria comprising ease of use and deployment, applicability to widespread installation base, or stability.