Use-After-Free Vulnerability in Linux Kernel Affecting Task Scheduling

CVE-2026-98866

What is CVE-2026-98866?

A vulnerability in the Linux kernel related to the task scheduling mechanism has been identified, which involves a use-after-free condition in the handling of cache groups. The introduction of a pointer to the cache group within the 'task_struct' allows direct access to the cache group by the scheduler, thereby eliminating unnecessary dependencies on the memory structure referenced by multiple tasks. This change prevents access to deallocated memory, ensuring stability and integrity in task scheduling, particularly during fork and exec operations. The updated scheduler code now properly manages reference counts and ensures that resources are correctly allocated and released, addressing the potential for system crashes or erratic behavior when tasks are switched.

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