CVE-2022-50253 bpf: make sure skb->len != 0 when redirecting to a tunneling device

In the Linux kernel, the following vulnerability has been resolved: bpf: make sure skb-len != 0 when redirecting to a tunneling device syzkaller managed to trigger another case where skb-len == 0 when we enter devqueuexmit: WARNING: CPU: 0 PID: 2470 at include/linux/skbuff.h:2576 skbassertlen...