Linux Kernel EUVD-2026-25546

The primary fix is to upgrade to a patched kernel version: Linux 6.18.23, Linux 6.19.13, or Linux 7.0 (mainline). The upstream fix deallocates repeat_call_control when damon_call() returns a failure, closing the leak. Patches are available directly from kernel.org stable trees at the commit references above. For Red Hat and SUSE environments, monitor vendor security advisories for backported errata. If immediate upgrade is not feasible, the most effective compensating control is to restrict access to the DAMON sysfs interface by limiting permissions on /sys/kernel/mm/damon/ to privileged users only, or by unloading the damon_sysfs kernel module if DAMON is not operationally required - note that unloading may impact memory pressure management tooling that relies on DAMON. Disabling vaddr monitoring contexts specifically (while leaving DAMON otherwise functional) would also prevent the vulnerable code path from being reached. There are no significant side effects to restricting sysfs access if DAMON is not actively used.