CVE-2025-68780

kernel: sched/deadline: only set free_cpus for online runqueues

Loading…

Severity

Low

Red Hat Product Security

5.5

CVSS 3.1

Review impact separately from score.

Published · January 13, 2026

Updated · June 28, 2026

Description

A scheduling flaw was found in the Linux kernel's SCHED_DEADLINE implementation. The cpudl_clear() function can incorrectly set the free_cpus bit for an offline CPU. This causes deadline tasks to be pushed to powered-down CPUs, where they cannot execute, resulting in task starvation for SCHED_DEADLINE workloads.

Statement

This affects systems using SCHED_DEADLINE real-time scheduling with CPU hotplug operations. Tasks pushed to offline CPUs will not run until the scheduler detects the issue. Systems not using SCHED_DEADLINE or without CPU hotplug activity are unaffected.

CVSS score applicability

The CVSS score(s) listed for this vulnerability do not reflect the associated product's status, and are included for informational purposes to better understand the severity of this vulnerability.

Mitigation

No mitigation is specified in collected source.

CVSS / CWE

CVSS 3.1 · 5.5
CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:H

CWE-367 · Time-of-check Time-of-use (TOCTOU) Race Condition