CVE-2026-74329

A flaw was found in the Linux kernel's watchdog subsystem. When a watchdog device is unregistered, its Power Management (PM) notifier may not be properly removed. This can lead to a stale pointer being used during a subsequent suspend/resume operation, potentially causing system instability or a denial of service.

A stale PM notifier can remain registered after watchdog device unregister when WDOG_NO_PING_ON_SUSPEND is set. A later suspend or resume notification may call watchdog_pm_notifier through an unregistered watchdog_device or after wd_data has been cleared, causing a kernel crash and potentially a use-after-free if the embedded notifier memory was freed and reused. For the CVSS the PR:L is used in the paranoid case because some deployments may delegate device unbind, hotplug, or suspend control to a reduced local account rather than full administrator access. The issue is not network reachable and requires local control over the watchdog device lifecycle or power management path. Impact is at least local denial of service via kernel crash and in worst case may allow confidentiality and integrity impact due to a stale notifier based use-after-free.

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 don't meet the Red Hat Product Security criteria comprising ease of use and deployment, applicability to widespread installation base or stability.