CVE-2026-74594

CVE CVE-2026-74594EUVD EUVD-2026-64531Published 2026-08-22T15:31:44.000ZLast changed 2026-08-25T05:40:21.000ZCVSS 7.8

What the advisory describes

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 prevented this but raced trigger creation instead: the deletion could cancel the timer that a new trigger set armed during the grace period and, as creation also reinitialized the timer at the time, corrupt it. 8f91efd870ea ("psi: Fix race between psi_trigger_create/destroy") moved the initialization into group_init() and the deletion into the locked section, trading the creation races for the window above. Neither placement in the destruction path works. A pending timer firing while the group is alive is harmless though. poll_timer_fn() just wakes the rtpoll waitqueue and doesn't re-arm itself. Bind the timer to the group's lifetime instead and shut it down in psi_cgroup_free(). Nothing can arm it by then. timer_shutdown_sync() because the timer is never armed again.

Source: EUVD (ENISA), in the words of the advisory.

Products the advisory names

These come from the advisory itself, not from any check we performed.

• Linux — Linux 8f91efd870ea5d8bc10b0fcc9740db51cd4c0c83 <310b5a537a78c358a4cd244bd767c1a517a05459; patch: 6.6.152; patch: 6.12.104; patch: 7.1.9; 5.10.50 <5.10.266; 979965c33f734a1666af67900408f997ac669c23; patch: 5.15.217; 8f91efd870ea5d8bc10b0fcc9740db51cd4c0c83 <611e7821c4f83a671455658797336faecc3a5196; 8f91efd870ea5d8bc10b0fcc9740db51cd4c0c83 <5457025fa8ca3c0d2732109513de839e3e797190; patch: 0; e1e5e263bbe0e6e9c3db36aa48a3c8acf546fa49; patch: 7.2; 8f91efd870ea5d8bc10b0fcc9740db51cd4c0c83 <894a9300d7fb2e2951da92e565ae6de7ddfb0a69; patch: 6.18.45; 5.13.2 <5.14; 8f91efd870ea5d8bc10b0fcc9740db51cd4c0c83 <8037c5b2b2a447df52542f4d8535895d837bdcbd; 6bfcb6178925b1fd28c102e53d403091b8f49396 <4addb102154b7cf6e2310ccbe20c3c08619e520d; patch: 5.10.266; 8f91efd870ea5d8bc10b0fcc9740db51cd4c0c83 <806fcff98c1d7cb3c1dc0015e55ebdbe819e6b08; patch: 6.1.183; 5.12.17 <5.13; 8f91efd870ea5d8bc10b0fcc9740db51cd4c0c83 <1e5ca82eee59caca6988f9d6e859786aab8a5fa0; 5.14

The versions shown are the advisory's own. Patchlage compares no version numbers and derives no judgement from them — which version is installed is something a person has to look up.

Carried in the product catalogue

An estate covering these products can be recorded in Patchlage. An advisory about them appears in the next morning's situation report.

• Linux — Linux

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