net_sched: sch_sfq: reject invalid perturb period

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CVE-2025-38193

CVE-2025-38193 affects the Linux kernel net_sched component sch_sfq. The issue is a missing range check for perturb_period, which could cause perturb_period * HZ to overflow and become invalid, enabling a race condition. The provided examples show invalid values producing errors and a valid value...