[$] Securing BPF programs before and after verification

BPF is in a unique position in terms of security. It runs in a privilegedcontext, within the kernel, and can have access to many sensitive details of thekernel's operation. At the same time, unlike kernel modules, BPF programs aren't signed.Additionally, the mechanisms behind BPF present challenges to implementingsigning or other security features. Three nearly back-to-back sessions at the2024Linux Storage,Filesystem, Memory Management, and BPF Summitaddressed some of the potential security problems.