The affected RISC‑V Linux kernel contains the function vec_check_unaligned_access_speed_all_cpus marked with the __init attribute, meaning its code is removed from memory after the init phase. The function runs in a background thread calling SBI for probe work. If that thread remains active after the boot sequence and the .init.text section is unmapped, the thread attempts to fetch instructions from freed memory, generating an instruction page fault and forcing a kernel panic. This flaw causes a denial of service but does not provide attacker control over the system.

Any Linux kernel compiled for RISC‑V that includes the vec_check_unaligned_access_speed_all_cpus function with the __init attribute is impacted. Distributions shipping such kernels—\nincluding recent releases with the function unmodified—are potentially vulnerable. The issue is specific to RISC‑V builds; other architectures are unaffected.

The vulnerability operates automatically during system boot or normal operation; no external input or privilege escalation is required. The hazard is a spontaneous kernel crash, making the risk high for any affected system. No publicly available exploit binaries exist, but triggering the fault is trivial. The EPSS score is unavailable and the bug is not listed in the CISA KEV catalog. The likely attack vector is normal boot or resume from a running system when the background thread still attempts to execute from the freed init region.