CVE-2026-23371

/// Technical description

In the Linux kernel, the following vulnerability has been resolved:

sched/deadline: Fix missing ENQUEUE_REPLENISH during PI de-boosting

Running stress-ng --schedpolicy 0 on an RT kernel on a big machine

might lead to the following WARNINGs (edited).

sched: DL de-boosted task PID 22725: REPLENISH flag missing

WARNING: CPU: 93 PID: 0 at kernel/sched/deadline.c:239 dequeue_task_dl+0x15c/0x1f8

... (running_bw underflow)

Call trace:

dequeue_task_dl+0x15c/0x1f8 (P)

dequeue_task+0x80/0x168

deactivate_task+0x24/0x50

push_dl_task+0x264/0x2e0

dl_task_timer+0x1b0/0x228

__hrtimer_run_queues+0x188/0x378

hrtimer_interrupt+0xfc/0x260

...

The problem is that when a SCHED_DEADLINE task (lock holder) is

changed to a lower priority class via sched_setscheduler(), it may

fail to properly inherit the parameters of potential DEADLINE donors

if it didn't already inherit them in the past (shorter deadline than

donor's at that time). This might lead to bandwidth accounting

corruption,

/// Remediation

Check the references section for vendor advisories, patches, and mitigation guidance. If immediate patching is not possible, review the CVSS vector to understand the attack surface and apply compensating controls such as network segmentation or access restrictions.

/// References