CVE-2026-46154 sched_ext: Read scx_root under scx_cgroup_ops_rwsem in cgroup setters

In the Linux kernel, the following vulnerability has been resolved: schedext: Read scxroot under scxcgroupopsrwsem in cgroup setters scxgroupsetweight,idle,bandwidth cache scxroot before acquiring scxcgroupopsrwsem, so the pointer can be stale by the time the op runs. If the loaded scheduler is...