{"cve":"CVE-2026-74594","nvd":{"published":"2026-08-22T16:16:31.680","modified":"2026-10-16T20:17:44.737","status":"Received","description":"In the Linux kernel, the following vulnerability has been resolved:\n\nsched/psi: Shut down rtpoll_timer in psi_cgroup_free()\n\npsi_schedule_rtpoll_work() is called locklessly from the scheduler hotpath\nand can race psi_trigger_destroy() taking down the last rtpoll trigger under\nrtpoll_trigger_lock:\n\n  psi_schedule_rtpoll_work()        psi_trigger_destroy()\n\n  rcu_read_lock();\n  task = rcu_dereference(rtpoll_task);\n                                    rcu_assign_pointer(rtpoll_task, NULL);\n                                    timer_delete(&rtpoll_timer);\n  mod_timer(&rtpoll_timer, ...);\n  rcu_read_unlock();\n                                    synchronize_rcu();\n                                    kthread_stop(task_to_destroy);\n\nThe group can then be freed with the re-armed timer still pending, and\npoll_timer_fn() runs on freed memory.\n\n461daba06bdc (\"psi: eliminate kthread_worker from psi trigger scheduling\nmechanism\") deleted the timer synchronously after the synchronize_rcu(),\nwhich prevented this but raced trigger creation instead: the deletion could\ncancel the timer that a new trigger set armed during the grace period and,\nas creation also reinitialized the timer at the time, corrupt it.\n8f91efd870ea (\"psi: Fix race between psi_trigger_create/destroy\") moved the\ninitialization into group_init() and the deletion into the locked section,\ntrading the creation races for the window above.\n\nNeither placement in the destruction path works. A pending timer firing\nwhile the group is alive is harmless though. poll_timer_fn() just wakes the\nrtpoll waitqueue and doesn't re-arm itself. Bind the timer to the group's\nlifetime instead and shut it down in psi_cgroup_free(). Nothing can arm it\nby then. timer_shutdown_sync() because the timer is never armed again.","cvss_v4":null,"cvss_v3":{"version":"3.1","vector":"CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H","score":7.8},"cwes":[],"references":["https://git.kernel.org/stable/c/1e5ca82eee59caca6988f9d6e859786aab8a5fa0","https://git.kernel.org/stable/c/310b5a537a78c358a4cd244bd767c1a517a05459","https://git.kernel.org/stable/c/4addb102154b7cf6e2310ccbe20c3c08619e520d","https://git.kernel.org/stable/c/5457025fa8ca3c0d2732109513de839e3e797190","https://git.kernel.org/stable/c/611e7821c4f83a671455658797336faecc3a5196"],"products":[],"source":"nvd","synced_at":"2026-10-19T22:49:38.260478770+00:00"},"epss":{"cve":"CVE-2026-74594","score":0.00129,"percentile":0.02532,"date":"2026-10-25"},"kev":null,"osv":[],"attribution":["This product uses the NVD API but is not endorsed or certified by the NVD.","EPSS scores: FIRST Exploit Prediction Scoring System, https://www.first.org/epss","Known exploited vulnerabilities: CISA Known Exploited Vulnerabilities Catalog, https://www.cisa.gov/known-exploited-vulnerabilities-catalog","Package advisories: OSV (https://osv.dev), from the GitHub Advisory Database, PyPA, Go, RustSec and other ecosystem databases, under CC-BY 4.0 or CC0","CVE records: the CVE Program's CVE List (https://www.cve.org), under its terms of use (https://www.cve.org/Legal/TermsOfUse). CVE is a registered trademark of The MITRE Corporation; this product is not affiliated with the CVE Program."]}