Linux Kernel Scheduling Vulnerability in Fair Scheduling Class

CVE-2026-99205

What is CVE-2026-99205?

A scheduling vulnerability in the Linux kernel can lead to CPU idling even with runnable tasks present. This issue arises in the fair scheduling class when class changes for queued tasks are not appropriately managed. As a result, the kernel may fail to recognize higher priority tasks leading to inefficient processing and resource utilization. The vulnerability stems from a race condition in the scheduling functions, necessitating the call to wakeup_preempt() in the sched_change_end() function to ensure proper class recognition and optimal task scheduling.

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