CVE-2025-21965

In the Linux kernel, the following vulnerability has been resolved:

sched_ext: Validate prev_cpu in scx_bpf_select_cpu_dfl()

If a BPF scheduler provides an invalid CPU (outside the nr_cpu_ids
range) as prev_cpu to scx_bpf_select_cpu_dfl() it can cause a kernel
crash.

To prevent this, validate prev_cpu in scx_bpf_select_cpu_dfl() and
trigger an scx error if an invalid CPU is specified.