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On 23 March 2015 at 10:46, Peter Humphrey <peter@××××××××××××.uk> wrote: |
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> On Sunday 22 March 2015 14:36:36 Jc García wrote: |
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> > 2015-03-22 4:30 GMT-06:00 Peter Humphrey <peter@××××××××××××.uk>: |
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> > > On Saturday 21 March 2015 16:20:17 Jc García wrote: |
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> > >> > Interesting. But as I said ealier, I can reboot the system when I am |
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> > >> > a |
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> > >> > user by Ctrl+Alt+Delete. The user can reboot the system, but can't |
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> > >> > shut |
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> > >> > down? Strange |
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> > >> |
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> > >> It's not strange, `man 2 reboot`. It's a defined behavior. |
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> > > |
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> > > I'm with German here. Being designed that way doesn't stop it being |
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> > > strange. |
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> > I see it as a last resource available for rebooting under any |
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> > circumstances( Similar to what you can do with Sysrq). |
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> > |
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> > > Consider: I'm an ordinary user sitting at a terminal. I'm not allowed |
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> to |
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> > > halt the machine, but I am allowed to reboot it into perhaps some quite |
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> > > other configuration. Or I can keep rebooting it over and again, |
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> > > effectively preventing the machine from doing its job. How does that |
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> > > make sense? |
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> > It doesn't and that's why it's configurable, if you are in a high |
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> > security requiring environment, you disable it. |
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> |
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> The consensus seems to be that there's no point in trying to prevent a user |
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> from rebooting the machine, and I'm happy to go along with that. |
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> |
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> The remaining question is: why is the user not allowed to halt it? |
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> |
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> -- |
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> Rgds |
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> Peter. |
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> |
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> |
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> |
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Maybe some people here missed my post. |
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You CAN allow the user to halt: just substitute |
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ca:12345:ctrlaltdel:/sbin/shutdown -r now |
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with |
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ca:12345:ctrlaltdel:/sbin/shutdown -P now |
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in /etc/inittab and Ctrl-Alt-Del will shutdown instead of reboot. |
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In fact, Ctrl-Alt-Del can be set up to do whatever you want and will |
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have root privileges. |
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If this is a security hole for your use case, you can comment it or set |
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it to |
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ca:12345:ctrlaltdel: /bin/echo 'Hey, don't touch me there!' |
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, or you can disable it entirely in the kernel. |
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-- |
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Emanuele |
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