On Dec 3, 2013 1:51 AM, "Tom Gundersen" <<a href="mailto:teg@jklm.no">teg@jklm.no</a>> wrote: > > On Tue, Dec 3, 2013 at 12:04 AM, Kay Sievers <<a href="mailto:kay@vrfy.org">kay@vrfy.org</a>> wrote: > > On Mon, Dec 2, 2013 at 11:52 PM, Goffredo Baroncelli <<a href="mailto:kreijack@libero.it">kreijack@libero.it</a>> wrote: > > > >> I have ne question: what happens if a sysctl setting is in more than > >> one file ? systemd-sysctl is smart enough to write the last value or > >> perform several writes ? > > > > One write only, it logs at "info" level about overwritten values. > > > >>> Kay explained in IRC that we do not allow such actions, because access to > >>> the keyboad doesn't mean full access to the machine, and we default to safe > >>> settings. Allowing the reboot though logind is different, because the user > >>> must authenticate first to open a session. > >> > >> Sorry, but I cannot agree: from a theoretical point of view Kay has > >> reason. However who has access to the keyboard and not to the "power > >> switch" ? If I want to switch the PC and the software cannot allow it, I > >> unplug the main power... > > > > The keyboard is surely not the computer itself, the wires or the reset > > or power button. Login prompts must not have the ability to trigger > > unsafe options with the keyboard alone. > > It is useful to imagine an internet cafe, a library, or a school, > where the user may only have physical access to the keyboard, and not > the machine itself. But logind needs to be reconfigured anyway to disallow reboots in this situation, so why would sysctl be different? Also Ctrl-Alt-Del and/or the login manager's Reboot option.