CVE-2026-74594

Technical Description

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

sched/psi: Shut down rtpoll_timer in psi_cgroup_free()

psi_schedule_rtpoll_work() is called locklessly from the scheduler hotpath

and can race psi_trigger_destroy() taking down the last rtpoll trigger under

rtpoll_trigger_lock:

psi_schedule_rtpoll_work() psi_trigger_destroy()

rcu_read_lock();

task = rcu_dereference(rtpoll_task);

rcu_assign_pointer(rtpoll_task, NULL);

timer_delete(&rtpoll_timer);

mod_timer(&rtpoll_timer, ...);

rcu_read_unlock();

synchronize_rcu();

kthread_stop(task_to_destroy);

The group can then be freed with the re-armed timer still pending, and

poll_timer_fn() runs on freed memory.

461daba06bdc ("psi: eliminate kthread_worker from psi trigger scheduling

mechanism") deleted the timer synchronously after the synchronize_rcu(),

which preve

Remediation

Check the references section for vendor advisories, patches, and mitigation guidance. If immediate patching is not possible, review the CVSS vector to understand the attack surface and apply compensating controls such as network segmentation or access restrictions.

References