CVE-2024-53125 bpf: sync_linked_regs() must preserve subreg_def

In the Linux kernel, the following vulnerability has been resolved: bpf: synclinkedregs must preserve subregdef Range propagation must not affect subregdef marks, otherwise the following example is rewritten by verifier incorrectly when BPFFTESTRNDHI32 flag is set: 0: call bpfktimegetns call...