Linux Kernel CVE-2026-31544

Update to patched kernel versions: Linux 6.18.20, 6.19.10, or 7.0, whichever aligns with your stable release branch. Users on older stable branches (6.17 or earlier) should cherry-pick the fix commit (70d9bd9a2e683afe6200b0c20af22f06f1a199a4, 8414d2800c34528467df23ce6192c254a73e4459, or 555317d6100164748f7d09f80142739bd29f0cda) into their kernel source and rebuild. The fix modifies __scmi_event_handler_get_ops to return ERR_PTR(-ENODEV) instead of NULL when no handler is found, ensuring consistent error handling throughout the SCMI notification chain. For systems that cannot immediately patch, restrict local user access via principle of least privilege: disable non-essential user accounts, enforce strong authentication, and limit shell access to trusted administrators. Monitor kernel logs for SCMI-related errors or unexpected crashes, which may indicate exploitation attempts. Since the vulnerability requires local authenticated access, network-facing mitigations are not applicable; focus hardening efforts on local access controls and privilege escalation vectors.