bpf: Allow delete from sockmap/sockhash only if update is allowed

In the Linux kernel, the following vulnerability has been resolved: bpf: Allow delete from sockmap/sockhash only if update is allowed We have seen an influx of syzkaller reports where a BPF program attached to a tracepoint triggers a locking rule violation by performing a map_delete on a sockmap/sockhash. We don't intend to support this artificial use scenario. Extend the existing verifier allowed-program-type check for updating sockmap/sockhash to also cover deleting from a map. From now on only BPF programs which were previously allowed to update sockmap/sockhash can delete from these map types.