malformed autostart .desktop file prevents session opening

[mohican]

1) Ubuntu release : 12.04 LTS 64 bits

2) Application : startup procedure (package unknown )

3) What should happen :

When a .desktop file used in autostart (located in /etc/xdg/autostart/ or ~./config/autostart/) is corrupt, it should be skipped and session startup should continue.

4) What happens :
Session does not start (freeze).
Impossible to open ANY session from session manager (lightDM).

5) Détails :

I altered one of the .desktop file located in /etc/xdg/autostart/ in the purpose of having it start only in certain environment.

I edited the desktop file, adding two lines :

OnlyShowIn=Unity;GNOME;
AutostartCondition=GNOME if-session gnome-fallback

Note the error on the second line it should be (?) AutostartCondition=GNOME3 if-session gnome-fallback

After that no session did open. I had to remove the .desktop file from another OS.

6) How to reproduce :

Test case included for clipit application, to be copied in /etc/xdg/autostart with correct permissions.
Clipit should have been installed and launched once, before replacing its startup file with the one included, in order to reproduce the same conditions.

WARNING : make sure you can delete the file accessing it from another OS as you will not be able to start a session. (Or have another way to bypass the session startup)

[Fabio Marconi (fabiomarconi)]

Thank you for taking the time to make Ubuntu better. Since what you submitted is not really a bug, or a problem, but rather an idea to improve Ubuntu, you are invited to post your idea in Ubuntu Brainstorm at http://brainstorm.ubuntu.com/ where it can be discussed, voted by the community and reviewed by developers. Thanks for taking the time to share your opinion!

[mohican (mohican)]

I'm afraid I have not been understood.

This is not a suggestion to improve Ubuntu.

The fact that one corrupt third-party configuration file blocks the whole system making it totally unuseable, is A VERY SERIOUS BUG !

Please try to reproduce it, I gave a test case.

[mohican (mohican)]

If it can be reproduced, then it should even be marqued as a security issue.

Because if a third-party can introduce a buggous file in the autostart they can block all infected machines !

[mohican (mohican)]

After discussing with another user I understood that :

there is no security check on autostart scripts, therefore in a way there is no "bug". There's perhaps a missing feature.
That's one point of view.

On the other hand, the fact that the program that interprets the .desktop file freezes or crashes on something that is not interpretable is a "bug" of the interpretor, because it should instead bypass (and warn about it).

Now, the issue is not a rethoric one about calling this a bug or not.
The issue is where to report this problem so that it has a chance to be fixed ?
- here in the bug report ?
- in a feature request ? If so OK I will do it this way.

What do you think ?

[mohican (mohican)]

May be the exemple of HTML interpreters could be usefull :
If the HTML code is not valid, the interpreter does not crash, it ignores it.

[Fabio Marconi (fabiomarconi)]

Hello
If the system is set by Admin to start an application, it *has* to start it, because if the application is something security related or essential for the workflow, then is better not to proceed at all.
A valid option can be a popup alert informing that the system is stopped cause a problem in a startup file, but in every case the system needs to be stopped.
Assigned to upstart to evaluate.
Thanks
Fabio
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