CVE-2026-98463

/// Technical description

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

sched_ext: Derive SCX_RQ_IN_WAKEUP from the core enqueue flags

schedule_deferred_locked() skips scheduling a deferred action while

SCX_RQ_IN_WAKEUP is set and relies on the task_woken_scx() call that follows

a wakeup enqueue to run it. enqueue_task_scx() sets the flag from the merged

enqueue flags, which include the flags stashed for a remote activation.

move_remote_task_to_local_dsq() thus sets SCX_RQ_IN_WAKEUP on the

destination rq when the moved task was woken up, although no

task_woken_scx() follows that activation.

An IMMED insert into a busy destination requests a local reenqueue during

that enqueue. The request gets linked but not scheduled and stays pending

until an unrelated wakeup or preemption on that CPU runs the deferred

actions. The IMMED task sits behind the running task in the meantime. If

nothing runs them before the scheduler is disabled, the request outlives the

scheduler and points into its freed

/// 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