Copyright © 2012 Red Hat, Inc. All rights reserved. Moderate 2026-09-11T00:00:00 kernel: sched_ext: Replace SCX_RQ_BAL_KEEP with a dispatch verdict return 5.5 CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:H CWE-367

In the Linux kernel, the following vulnerability has been resolved: sched_ext: Replace SCX_RQ_BAL_KEEP with a dispatch verdict return SCX_RQ_BAL_KEEP tells the pick to keep running the previous task, a leftover from when balancing and picking were separate operations. An rq-level flag only works while dispatches and picks pair up one to one, which core scheduling breaks: selections interleave through dispatch's lock drops and a pick can consume a stale flag, keeping a task that has since been dequeued. Fixing core scheduling support requires the decision to travel with the dispatch that made it. Make scx_dispatch_sched() and balance_one() return an explicit verdict instead and drop the flag's plumbing from the tools autogen enum headers. Also factor the pick-side invocation, its follow-up queueing and the post-dispatch checks out of do_pick_task_scx() into dispatch_pick(). No functional changes intended. v2: Drop the SCX_RQ_BAL_KEEP plumbing from the tools autogen enum headers as well (Andrea).

A flaw was found in the Linux kernel's `sched_ext` component. Due to a logical error where a stale flag (`SCX_RQ_BAL_KEEP`) could be consumed, the scheduler might incorrectly keep a task running even after it has been dequeued. This could lead to unexpected task management behavior within the kernel.

Red Hat Enterprise Linux 10 Not affected kernel Red Hat Enterprise Linux 10 Not affected kernel-rt Red Hat Enterprise Linux 6 Not affected kernel Red Hat Enterprise Linux 7 Not affected kernel Red Hat Enterprise Linux 7 Not affected kernel-rt Red Hat Enterprise Linux 8 Not affected kernel Red Hat Enterprise Linux 8 Not affected kernel-rt Red Hat Enterprise Linux 9 Not affected kernel Red Hat Enterprise Linux 9 Not affected kernel-rt Red Hat OpenShift Container Platform 4 Not affected openshift/ose-rhel-coreos-8 Red Hat OpenShift Container Platform 4 Not affected openshift/ose-rhel-coreos-9 https://www.cve.org/CVERecord?id=CVE-2026-89519 https://nvd.nist.gov/vuln/detail/CVE-2026-89519 https://git.kernel.org/pub/scm/linux/security/vulns.git/plain/cve/published/2026/CVE-2026-89519.mbox