On Fri, 19 Apr 2024 at 17:44:35 +0200, Solar Designer wrote: > I guess > systemd's PrivateNetwork services generally don't configure networking > (they just give up network access), so would continue to work even with > capabilities disallowed?
I can't speak for systemd's PrivateNetwork services, but for the bubblewrap use-cases that I described elsewhere in the thread (Flatpak, libgnome-desktop etc.), `bwrap --unshare-net` does bring up the "lo" interface with address 127.0.0.1 and a route to 127.0.0.0/8 before it relinquishes its capabilities and execs the sandboxed program. Presumably this is because it's common for ordinary user-space applications to assume that they can "talk to themselves" via loopback, even if there is no external connectivity. smcv