Bug 911930

Summary: su stops audio (users ACL's are removed from audio device files)
Product: [Fedora] Fedora Reporter: Andrew Clayton <andrew>
Component: systemdAssignee: systemd-maint
Status: CLOSED CANTFIX QA Contact: Fedora Extras Quality Assurance <extras-qa>
Severity: unspecified Docs Contact:
Priority: unspecified    
Version: 18CC: johannbg, lnykryn, metherid, mschmidt, msekleta, notting, plautrba, systemd-maint, vpavlin
Target Milestone: ---   
Target Release: ---   
Hardware: Unspecified   
OS: Unspecified   
Whiteboard:
Fixed In Version: Doc Type: Bug Fix
Doc Text:
Story Points: ---
Clone Of: Environment:
Last Closed: 2013-02-18 15:58:13 UTC Type: Bug
Regression: --- Mount Type: ---
Documentation: --- CRM:
Verified Versions: Category: ---
oVirt Team: --- RHEL 7.3 requirements from Atomic Host:
Cloudforms Team: --- Target Upstream Version:
Embargoed:
Attachments:
Description Flags
3.8.0-rc7 kernel .config none

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.