CVE-2022-49975 bpf: Don't redirect packets with invalid pkt_len

In the Linux kernel, the following vulnerability has been resolved: bpf: Don't redirect packets with invalid pktlen Syzbot found an issue 1: fqcodeldrop try to drop a flow whitout any skbs, that is, the flow-head is null. The root cause, as the 2 says, is because that bpfprogtestrunskb run a bpf...