pfSense

A user reports seeing an unusual increase in the number of running processes.
The extra processes are all kernel/netlink_socket.

The user very helpfully narrowed this down to being caused by bsnmpd, and there's an obvious issue (with the benefit of hindsight, at least) in libpfctl's pfctl_get_rules_info() implementation. It opens a netlink socket, but fails to close it again.

See https://forum.netgate.com/topic/188050/24-03-causes-sustained-rise-in-processes-count-and-memory-usage for the full discussion.