CVE-2026-98087

/// Technical description

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

sched/rt,dl: Skip migrate-disabled tasks when picking a push candidate

A migrate_disable()'d RT task cannot be moved to another CPU, but the

scheduler still keeps such a task on that CPU's pushable list

(rq->rt.pushable_tasks) and still marks the runqueue RT-overloaded

(rq->rt.overloaded = 1). So the RT balancer keeps treating this CPU as

having a task to move away, and keeps trying to move the task, but the

push can never succeed. When the head is pinned, push_rt_task() does not

give up either. It falls back to pushing rq->curr instead, using the

per-CPU stopper, as added by commit a7c81556ec4d ("sched: Fix

migrate_disable() vs rt/dl balancing").

The CPU spends tens of milliseconds in this retry loop. The core is

isolated for real-time work, but during the loop nearly half of its time

is consumed by pushes that cannot succeed.

An ftrace capture of the affected CPU, with sched_switch enabled and

commit 94894c9c477e

/// 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