CVE Catalog

CVE-2026-68421

Low risk· EPSS 9%
Published: Updated: Translated: NVD NIST

Exploitation Probability (EPSS)

Low risk
0.19%

9th percentile - higher than 9% of all known CVEs

Summary

In the Linux kernel, the sched_ext subsystem has an issue with a warning in put_prev_task_scx() regarding core-sched forced idle. When a runnable task is forced idle by core scheduling, a warning is generated even though it is not an error. The fix gates the warning on sched_cpu_cookie_match(): a cookie mismatch means core scheduling forced the idle, while a match (or core scheduling off) still catches a genuine missing-ENQ_LAST drop.

Risk Assessment

The vulnerability may cause false warnings in system logs, which can hinder diagnosis of real issues, but does not pose a direct security threat.

Recommendation

Apply the Linux kernel patch that fixes the warning condition in put_prev_task_scx().

Other vulnerabilities in Linux kernel

See all
Original NVD description (English source)

In the Linux kernel, the following vulnerability has been resolved: sched_ext: Don't warn on core-sched forced idle in put_prev_task_scx() put_prev_task_scx() warns when a runnable task drops to a lower sched_class without SCX_OPS_ENQ_LAST, on the assumption that balance_one() would have kept it running. Core scheduling breaks that: a forced-idle SMT sibling reschedules through the core_pick fast path in pick_next_task(), which skips pick_task_scx() and thus balance_one(), so a runnable task can drop to idle with ENQ_LAST unset. Gate the warning on sched_cpu_cookie_match(): a cookie mismatch means core scheduling forced the idle, while a match (or core scheduling off) still catches a genuine missing-ENQ_LAST drop.

Vulnerability data from NVD (NIST) · CISA KEV · EPSS