Memory Management Flaw in Linux Kernel Affecting RISC-V Architecture

CVE-2026-80688

What is CVE-2026-80688?

A memory management issue in the Linux kernel's RISC-V implementation arises from an improper handling of the vec_check_unaligned_access_speed_all_cpus function. This function executes within a kernel thread (kthread), which may not complete before the system finishes booting and the free_initmem() function unmaps the memory section containing the initialized text. Consequently, if the probing for unaligned access speed is delayed—potentially due to debug prints added to the system's SBI (Supervisor Binary Interface)—the kthread may still be active when the system accesses freed memory, resulting in instruction page faults. This flaw emphasizes the need for careful memory management in kernel development.

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