CVE-2026-23294 bpf: Fix race in devmap on PREEMPT_RT

In the Linux kernel, the following vulnerability has been resolved: bpf: Fix race in devmap on PREEMPTRT On PREEMPTRT kernels, the per-CPU xdpdevbulkqueue bq can be accessed concurrently by multiple preemptible tasks on the same CPU. The original code assumes bqenqueue and devflush run atomically...