net_sched: Prevent creation of classes with TC_H_ROOT

These records connect through source-stated identifiers. Shared identifiers or dates alone do not establish shared exposure, root cause or applicability.

CVE-2025-21971 · Microsoft / collected KEV context

cve-program · CVE-2025-21971

• https://git.kernel.org/stable/c/e05d9938b1b0ac40b6054cc5fa0ccbd9afd5ed4c
• https://git.kernel.org/stable/c/7a82fe67a9f4d7123d8e5ba8f0f0806c28695006
• https://git.kernel.org/stable/c/003d92c91cdb5a64b25a9a74cb8543aac9a8bb48
• https://git.kernel.org/stable/c/e5ee00607bbfc97ef1526ea95b6b2458ac9e7cb7
• https://git.kernel.org/stable/c/78533c4a29ac3aeddce4b481770beaaa4f3bfb67
• https://git.kernel.org/stable/c/5c3ca9cb48b51bd72bf76b8b05e24f3cd53db5e7
• https://git.kernel.org/stable/c/94edfdfb9505ab608e86599d1d1e38c83816fc1c
• https://git.kernel.org/stable/c/0c3057a5a04d07120b3d0ec9c79568fceb9c921e

No related operational record is retained in the current change model.