Linux Kernel RCU Stalling Vulnerability in Realtek MIPS SoCs

CVE-2026-64248

What is CVE-2026-64248?

A vulnerability in the Linux kernel affects MIPS-based architectures, particularly those used in Realtek SoCs. The issue arises when the function smp_send_stop() parks secondary CPUs without notifying the RCU (Read-Copy Update) mechanism, leading to situations where the system hangs during reboot or shutdown. Specifically, this occurs because the RCU continues to expect a quiescent state from CPUs that are no longer operational. This problem, compounded by the changes made in the kernel version transition, can lead to a failure in completing grace periods required for system stability. Solutions involve the proper notification of dying CPUs to the RCU to help maintain system reliability during hotplug operations, ensuring a graceful shutdown process.

References