Bug 911930 - su stops audio (users ACL's are removed from audio device files)
Summary: su stops audio (users ACL's are removed from audio device files)
Keywords:
Status: CLOSED CANTFIX
Alias: None
Product: Fedora
Classification: Fedora
Component: systemd
Version: 18
Hardware: Unspecified
OS: Unspecified
unspecified
unspecified
Target Milestone: ---
Assignee: systemd-maint
QA Contact: Fedora Extras Quality Assurance
URL:
Whiteboard:
Depends On:
Blocks:
TreeView+ depends on / blocked
 
Reported: 2013-02-16 20:16 UTC by Andrew Clayton
Modified: 2013-02-18 19:18 UTC (History)
9 users (show)

Fixed In Version:
Clone Of:
Environment:
Last Closed: 2013-02-18 15:58:13 UTC
Type: Bug
Embargoed:


Attachments (Terms of Use)
3.8.0-rc7 kernel .config (61.47 KB, text/plain)
2013-02-17 23:20 UTC, Andrew Clayton
no flags Details

Description Andrew Clayton 2013-02-16 20:16:46 UTC
Hopefully this is the right component for this...

If I'm listening to music or watching a video, and I su to root, my audio stops.
This is due to my ACL's being removed from the audio device files. 

If I exit my root shell, the audio remains stopped.

If I exit my root shell and switch out of X and back in again (i.e, switch out to a VT and back again), my audio kicks back in.

If while I have my root shell, I do, loginctl activate <my session>, my audio starts up again.

This is with systemd-197-1.fc18.1.x86_64

Comment 1 Andrew Clayton 2013-02-17 23:18:44 UTC
I've just discovered that this doesn't happen using the Fedora kernel.

It does happen on my own built 3.8.0-rc7. Any idea's what bit of missing kernel config might account for this? It's the same kernel/config I was using on Fedora 16 just prior to upgrading.

Cheers,
Andrew

Comment 2 Andrew Clayton 2013-02-17 23:20:36 UTC
Created attachment 698657 [details]
3.8.0-rc7 kernel .config

.config for my 3.8.0-rc7 kernel. It didn't have this problem under Fedora 16.

Comment 3 Michal Schmidt 2013-02-18 14:51:00 UTC
My guess is CONFIG_AUDIT_LOGINUID_IMMUTABLE.

Comment 4 Andrew Clayton 2013-02-18 15:22:28 UTC
Actually, the Fedora kernel doesn't have that either.

One thing I'll try when I get home, is CONFIG_AUDITSYSCALL as that seems to enable the creation of the /proc/self/sessionid file which seems to be used by systemd.

As I notice here at work running a Fedora kernel, when I su to root only one session shows up in loginctl list-sessions (my user session) as opposed to also showing up a root session.

Comment 5 Michal Schmidt 2013-02-18 15:58:13 UTC
(In reply to comment #4)
> Actually, the Fedora kernel doesn't have that either.

Oh, it doesn't? ... You're right. This looks like an oversight. I'll ask the kernel maintainers to enable it in F19.

> One thing I'll try when I get home, is CONFIG_AUDITSYSCALL as that seems to
> enable the creation of the /proc/self/sessionid file which seems to be used
> by systemd.

Yes, this would explain it. I'm very sure the problem is related to audit.

> As I notice here at work running a Fedora kernel, when I su to root only one
> session shows up in loginctl list-sessions (my user session) as opposed to
> also showing up a root session.

This indicates that logind is making up session IDs instead of depending on the audit IDs.

CONFIG_AUDITSYSCALL will likely fix it for you. I'm closing this as CANTFIX, because the problem does not happen with the Fedora kernel.

Comment 6 Michal Schmidt 2013-02-18 17:09:17 UTC
(In reply to comment #5)
> I'll ask the kernel maintainers to enable it in F19.

I have posted a request to the mailing list:
http://lists.fedoraproject.org/pipermail/kernel/2013-February/004125.html

Comment 7 Andrew Clayton 2013-02-18 19:18:58 UTC
Just for the record, CONFIG_AUDITSYSCALL is indeed what was needed.


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