{"id":"CVE-2026-74594","title":"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() ta…","summary":"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() ta…","severity":"high","cvss":7.8,"cvssVector":"CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H","cwe":["CWE-416"],"vendor":"Linux","product":"Linux","affected":["Linux >= 6bfcb6178925b1fd28c102e53d403091b8f49396 < 4addb102154b7cf6e2310ccbe20c3c08619e520d","Linux >= 8f91efd870ea5d8bc10b0fcc9740db51cd4c0c83 < 894a9300d7fb2e2951da92e565ae6de7ddfb0a69","Linux >= 8f91efd870ea5d8bc10b0fcc9740db51cd4c0c83 < 1e5ca82eee59caca6988f9d6e859786aab8a5fa0","Linux >= 8f91efd870ea5d8bc10b0fcc9740db51cd4c0c83 < 310b5a537a78c358a4cd244bd767c1a517a05459","Linux >= 8f91efd870ea5d8bc10b0fcc9740db51cd4c0c83 < 806fcff98c1d7cb3c1dc0015e55ebdbe819e6b08","Linux >= 8f91efd870ea5d8bc10b0fcc9740db51cd4c0c83 < 8037c5b2b2a447df52542f4d8535895d837bdcbd","Linux >= 8f91efd870ea5d8bc10b0fcc9740db51cd4c0c83 < 611e7821c4f83a671455658797336faecc3a5196","Linux >= 8f91efd870ea5d8bc10b0fcc9740db51cd4c0c83 < 5457025fa8ca3c0d2732109513de839e3e797190","Linux e1e5e263bbe0e6e9c3db36aa48a3c8acf546fa49","Linux 979965c33f734a1666af67900408f997ac669c23","Linux >= 5.10.50 < 5.10.266","Linux >= 5.12.17 < 5.13","Linux >= 5.13.2 < 5.14","Linux 5.14"],"published":"2026-08-22","updated":"2026-10-16","sourceUpdated":"2026-10-16T20:17:44.737","source":"NVD","sourceUrl":"https://nvd.nist.gov/vuln/detail/CVE-2026-74594","references":[{"url":"https://git.kernel.org/stable/c/1e5ca82eee59caca6988f9d6e859786aab8a5fa0","label":"416baaa9-dc9f-4396-8d5f-8c081fb06d67"},{"url":"https://git.kernel.org/stable/c/310b5a537a78c358a4cd244bd767c1a517a05459","label":"416baaa9-dc9f-4396-8d5f-8c081fb06d67"},{"url":"https://git.kernel.org/stable/c/4addb102154b7cf6e2310ccbe20c3c08619e520d","label":"416baaa9-dc9f-4396-8d5f-8c081fb06d67"},{"url":"https://git.kernel.org/stable/c/5457025fa8ca3c0d2732109513de839e3e797190","label":"416baaa9-dc9f-4396-8d5f-8c081fb06d67"},{"url":"https://git.kernel.org/stable/c/611e7821c4f83a671455658797336faecc3a5196","label":"416baaa9-dc9f-4396-8d5f-8c081fb06d67"},{"url":"https://git.kernel.org/stable/c/8037c5b2b2a447df52542f4d8535895d837bdcbd","label":"416baaa9-dc9f-4396-8d5f-8c081fb06d67"},{"url":"https://git.kernel.org/stable/c/806fcff98c1d7cb3c1dc0015e55ebdbe819e6b08","label":"416baaa9-dc9f-4396-8d5f-8c081fb06d67"},{"url":"https://git.kernel.org/stable/c/894a9300d7fb2e2951da92e565ae6de7ddfb0a69","label":"416baaa9-dc9f-4396-8d5f-8c081fb06d67"},{"url":"https://security.access.redhat.com/data/csaf/v2/vex/2026/cve-2026-74594.json"},{"url":"https://access.redhat.com/security/cve/CVE-2026-74594"},{"url":"https://bugzilla.redhat.com/show_bug.cgi?id=2521435"},{"url":"https://www.cve.org/CVERecord?id=CVE-2026-74594"},{"url":"https://nvd.nist.gov/vuln/detail/CVE-2026-74594"},{"url":"https://kernelcve.org/list/?q=CVE-2026-74594"},{"url":"https://lore.kernel.org/linux-cve-announce/2026082213-CVE-2026-74594-644a@gregkh/T"}],"tags":["nvd","cve.org","csaf","vex","red-hat","score-dispute"],"epss":0.00129,"epssPercentile":0.02546,"ssvc":{"exploitation":"none","automatable":"no","technicalImpact":"total","timestamp":"2026-10-16T19:01:40.497794Z"},"scores":{"nvd":7.8,"vendor":4.7},"ingestedAt":"2026-08-23T09:45:33.257Z","slug":"CVE-2026-74594","body":"## Overview\n\nIn 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.\n\n## Remediation\n\nRefer to the linked advisories for vendor-supplied fixes and affected version ranges.\n\n## Vendor advisories\n\n- **Red Hat VEX** · Moderate · affected: Red Hat Enterprise Linux 8 · no fix planned: Red Hat Enterprise Linux 8 · updated 2026-10-26 · [vex](https://security.access.redhat.com/data/csaf/v2/vex/2026/cve-2026-74594.json)","depth":"twilight","depthScore":43,"depthScoreParts":{"impact":42.9,"likelihood":0,"exploitation":0,"ransomware":0},"changes":[{"seq":220158,"id":"CVE-2026-74594","ts":1791984789492,"field":"cvss","old":null,"new":"7.8"},{"seq":220157,"id":"CVE-2026-74594","ts":1791984789492,"field":"severity","old":"none","new":"high"}]}