CVE-2026-45919

Technical Description

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

sched/rt: Skip currently executing CPU in rto_next_cpu()

CPU0 becomes overloaded when hosting a CPU-bound RT task, a non-CPU-bound

RT task, and a CFS task stuck in kernel space. When other CPUs switch from

RT to non-RT tasks, RT load balancing (LB) is triggered; with

HAVE_RT_PUSH_IPI enabled, they send IPIs to CPU0 to drive the execution

of rto_push_irq_work_func. During push_rt_task on CPU0,

if next_task->prio < rq->donor->prio, resched_curr() sets NEED_RESCHED

and after the push operation completes, CPU0 calls rto_next_cpu().

Since only CPU0 is overloaded in this scenario, rto_next_cpu() should

ideally return -1 (no further IPI needed).

However, multiple CPUs invoking tell_cpu_to_push() during LB increments

rd->rto_loop_next. Even when rd->rto_cpu is set to -1, the mismatch between

rd->rto_loop and rd->rto_loop_next forces rto_next_cpu() to restart its

search from -1. With CPU0 remaining overloaded (satisfying rt_

Remediation

Check the references section for vendor advisories and patches from linux. Update linux_kernel to the latest patched version. 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.

Affected Products

References