4 ms·

We send SIGHUP btw. The kernel's own sending of SIGHUP is bound to the TTY concept btw, which is specific to TTY logins only, not graphical ones. That said the

We send SIGHUP btw. The kernel's own sending of SIGHUP is bound to the TTY concept btw, which is specific to TTY logins only, not graphical ones. That said the question is not so much about who sends what, but more about whether a secure system should allow user code to escape lifecycle management or whether logging out means logging out and giving up all resources.

tyingq 8y ago
I get what you're saying. However, I'd probably apply the kernel rule of "when maintaining the kernel, do not do something which breaks user programs/applications". Yes, this isn't the kernel, but it's comparable in being a core function that heavily affects userland stuff.
- pas 8y ago
  Sometimes the ole way o' logg out is just insecure. And there is no way to conjure up a new backward compatible and secure way. cgroups work well, especially because they are not opt-in. That means programs daemonizing either has to set themselves up as a system service or start a new logind scope (or PAM session, etc. which translates to escaping the cgroup, which requires user approval to remain secure).
v_lisivka 8y ago
If you created a problem, it's your duty to provide a workaround or a solution to the problem. Why not provide systemd specific version of `nohup` for such cases and encourage users to use it instead of old and insecure version?
- deleted 8y ago
  [deleted]
inferiorhuman 8y ago
> more about whether a secure system should allow user code to escape lifecycle management Please stop trotting that tired old line out. It is simply untrue. Systemd does the exact opposite of providing increased security. If nothing else the greatly increased surface area of systemd makes for a less secure system. The pwnie articulates a number of other ways in which your code and your behavior are actively reducing the security of Linux.
onlydeadheroes 8y ago
I know right, I run openvpn as user nobody and I keep thinking that nobody user better stay logged in!

tyingq 8y ago

I get what you're saying. However, I'd probably apply the kernel rule of "when maintaining the kernel, do not do something which breaks user programs/applications". Yes, this isn't the kernel, but it's comparable in being a core function that heavily affects userland stuff.

pas 8y ago
Sometimes the ole way o' logg out is just insecure. And there is no way to conjure up a new backward compatible and secure way. cgroups work well, especially because they are not opt-in. That means programs daemonizing either has to set themselves up as a system service or start a new logind scope (or PAM session, etc. which translates to escaping the cgroup, which requires user approval to remain secure).

v_lisivka 8y ago

If you created a problem, it's your duty to provide a workaround or a solution to the problem. Why not provide systemd specific version of `nohup` for such cases and encourage users to use it instead of old and insecure version?

deleted 8y ago
[deleted]

inferiorhuman 8y ago

> more about whether a secure system should allow user code to escape lifecycle management Please stop trotting that tired old line out. It is simply untrue. Systemd does the exact opposite of providing increased security. If nothing else the greatly increased surface area of systemd makes for a less secure system. The pwnie articulates a number of other ways in which your code and your behavior are actively reducing the security of Linux.

onlydeadheroes 8y ago

I know right, I run openvpn as user nobody and I keep thinking that nobody user better stay logged in!