published August 10, 2026
In the Linux kernel, the following vulnerability has been resolved:
watchdog: pretimeout: Fix UAF in watchdog_unregister_governor()
When a watchdog governor is unregistered, it updates existing watchdog
devices that were using this governor by falling back to `default_gov`.
If the governor being unregistered is currently set as `default_gov`,
the `default_gov` is never cleared. This leads to 2 use-after-free
issues:
1. New watchdog devices registered after this point will inherit the
dangling `default_gov`.
2. Existing watchdog devices using the unregistered governor will have
their `wdd->gov` reassigned to the dangling `default_gov`.
Fix the UAF by clearing `default_gov` if it matches the governor being
unregistered.