CVE-2026-80660

A flaw was found in the Linux kernel's hwmon (occ) component. This vulnerability occurs when occ_active(false) or occ_shutdown() attempt to unregister sysfs devices while holding the occ->lock. During this process, sysfs callbacks can re-enter the OCC update path and try to acquire the occ->lock again, creating a circular locking dependency. This can lead to a deadlock, causing a Denial of Service (DoS) where the system becomes unresponsive.

A flaw was found in the Linux kernel hwmon OCC (On-Chip Controller) driver, rated by Red Hat Product Security as having Moderate security impact. When occ_active(false) or occ_shutdown() unregister sysfs-backed devices while holding occ->lock, hwmon_device_unregister() and sysfs_remove_group() can wait for active sysfs callbacks to drain, and those callbacks can re-enter the OCC update path and attempt to acquire occ->lock again. This creates a circular locking dependency (occ->lock -> sysfs callback drain versus sysfs callback -> occ->lock) that can lead to a deadlock, leaving the system unresponsive and resulting in a local denial of service (CVSS 3.1 score 5.5, AV:L/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:H). The currently tracked Red Hat Enterprise Linux and Red Hat In-Vehicle OS kernel and kernel-rt components are not affected by this flaw, because the vulnerable code is not present in those shipped builds.

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.