[PATCH bpf-next] bpf, capabilities: introduce CAP_BPF

[Steven Rostedt]

On Thu, 29 Aug 2019 10:23:10 -0700
Alexei Starovoitov <alexei.starovoitov at gmail.com> wrote:

> > CAP_TRACE_KERNEL: Use all of perf, ftrace, kprobe, etc.
> > 
> > CAP_TRACE_USER: Use all of perf with scope limited to user mode and uprobes.  
> 
> imo that makes little sense from security pov, since
> such CAP_TRACE_KERNEL (ex kprobe) can trace "unrelated user process"
> just as well. Yet not letting it do cleanly via uprobe.
> Sort of like giving a spare key for back door of the house and
> saying no, you cannot have main door key.

I took it as CAP_TRACE_KERNEL as a superset of CAP_TRACE_USER. That is,
if you have CAP_TRACE_KERNEL, by default you get USER. Where as
CAP_TRACE_USER, is much more limiting.

-- Steve