CVE-2026-74670

In the Linux kernel, the following vulnerability has been resolved:

ipvs: stop estimator after disabled calc phase

IPVS estimator kthread 0 starts with zeroed chain and tick limits until

its initial calculation phase completes. If network namespace teardown

clears ipvs->enable during that phase, ip_vs_est_calc_phase() can return

without installing positive limits.

The kthread can then continue into its main loop and drain

est_temp_list with zero chain_max, tick_max and est_max_count values.

Each enqueue consumes one available tick row, but est_count never

reaches the zero est_max_count value. After all rows are consumed, the

row lookup returns IPVS_EST_NTICKS and ip_vs_enqueue_estimator() writes

past the ticks and tick_len arrays.

Exit kthread 0 after the calculation phase if the kthread is stopping or

IPVS has been disabled. That keeps temporary estimators from being

drained after the limits failed to initialize.

Estimator kthreads can now self-exit before teardown or reload stops

kd->task. Keep an extra task reference after creation and release it

with kthread_stop_put(), so kd->task remains valid until the stop paths

consume that reference.