pulsesink: Segfault in pulsesink.c:2077 gst_pulsesink_pad_acceptcaps()

[Erik Botö]

Impact:
segfaults happening sometimes

Test Case:
No easy way to reproduce, the bug reporter has access to a closed source app which tends to trigger the issue and can do testing on it though

Regression potential:
Check that sound and video playing in rhythmbox, totem, etc still work as it should...

-----

There's an upstream bug at: https://bugzilla.gnome.org/show_bug.cgi?id=683782

I looked at the suggested patch and made it work in the source package of Ubuntu 12.04, see attached patch. This applies cleanly on top a fresh apt-get source gst-plugins-good0.10 . Using this patch solves our crash.

The source package is: gst-plugins-good0.10

$ lsb_release -rd
Description: Ubuntu 12.04.1 LTS
Release: 12.04

$ apt-cache policy gstreamer0.10-pulseaudio
gstreamer0.10-pulseaudio:
  Installed: 0.10.31-1ubuntu1
  Candidate: 0.10.31-1ubuntu1
  Version table:
 *** 0.10.31-1ubuntu1 0
        500 http://se.archive.ubuntu.com/ubuntu/ precise/main i386 Packages
        100 /var/lib/dpkg/status

[Ubuntu Foundations Team Bug Bot (crichton)]

The attachment "pulsesink-fix.patch" of this bug report has been identified as being a patch. The ubuntu-reviewers team has been subscribed to the bug report so that they can review the patch. In the event that this is in fact not a patch you can resolve this situation by removing the tag 'patch' from the bug report and editing the attachment so that it is not flagged as a patch. Additionally, if you are member of the ubuntu-reviewers team please also unsubscribe the team from this bug report.

[This is an automated message performed by a Launchpad user owned by Brian Murray. Please contact him regarding any issues with the action taken in this bug report.]

[David Henningsson (diwic)]

Hi Erik and thanks for your patch!

Could you give a good test example on how to reproduce the crash? This is going to be necessary if you want it to reach a stable release of Ubuntu. See https://wiki.ubuntu.com/StableReleaseUpdates for details.

[Erik Botö (erik-boto)]

Unfortunately (or maybe fortunately) I can only reproduce the problem using a some of our closed source code, and even then it's a relatively uncommon crash. I only had a small amount of time playing around trying to trigger the bug in a minimal test, but were unable to do so.

I understand that this might disqualify it from getting into the stable release. If someone else has the same issue they'll hopefully find this bug and can build a fixed version of their own, just like we do internally.

[Sebastien Bacher (seb128)]

it's possible to SRU with a testcase stating that the bug is hard to trigger and that testers should ensure things keep working without regression

[Sebastien Bacher (seb128)]

The patch commited upstream:
http://cgit.freedesktop.org/gstreamer/gst-plugins-good/patch/?id=d2fdc26c38acc243ba7912f4db17f63fe0d54632

is slightly different ... is there any chance you could test it/make it apply to the current gst-plugins-good version (seems to not apply in its current form to 0.10.31)

[Erik Botö (erik-boto)]

Updated patch. Tested it and it also solves the crash we see.

[Launchpad Janitor (janitor)]

This bug was fixed in the package gst-plugins-good0.10 - 0.10.31-3ubuntu3

---------------
gst-plugins-good0.10 (0.10.31-3ubuntu3) raring; urgency=low

  * debian/patches/git_new_v4l_building.patch: "v4l2: fix build with
    recent kernels, the v4l2_buffer input field was removed"
 -- Sebastien Bacher <email address hidden> Fri, 16 Nov 2012 15:06:05 +0100

[Clint Byrum (clint-fewbar)]

Hello Erik, or anyone else affected,

Accepted gst-plugins-good0.10 into quantal-proposed. The package will build now and be available at http://launchpad.net/ubuntu/+source/gst-plugins-good0.10/0.10.31-3ubuntu1.1 in a few hours, and then in the -proposed repository.

Please help us by testing this new package. See https://wiki.ubuntu.com/Testing/EnableProposed for documentation how to enable and use -proposed. Your feedback will aid us getting this update out to other Ubuntu users.

If this package fixes the bug for you, please change the bug tag from verification-needed to verification-done. If it does not, change the tag to verification-failed. In either case, details of your testing will help us make a better decision.

Further information regarding the verification process can be found at https://wiki.ubuntu.com/QATeam/PerformingSRUVerification . Thank you in advance!

[Clint Byrum (clint-fewbar)]

Hello Erik, or anyone else affected,

Accepted gst-plugins-good0.10 into precise-proposed. The package will build now and be available at http://launchpad.net/ubuntu/+source/gst-plugins-good0.10/0.10.31-1ubuntu1.1 in a few hours, and then in the -proposed repository.

Please help us by testing this new package. See https://wiki.ubuntu.com/Testing/EnableProposed for documentation how to enable and use -proposed. Your feedback will aid us getting this update out to other Ubuntu users.

If this package fixes the bug for you, please change the bug tag from verification-needed to verification-done. If it does not, change the tag to verification-failed. In either case, details of your testing will help us make a better decision.

Further information regarding the verification process can be found at https://wiki.ubuntu.com/QATeam/PerformingSRUVerification . Thank you in advance!

[Iain Lane (laney)]

Erik,

Are you now running the -proposed versions of gst-plugins-good0.10? Can you verify that they fix the issue? We need someone to confirm this before the packages can be rolled out to all users.

I'd like to fix a different bug in this package in the stable releases and it's preferable that we finish this fix up before doing that.

Cheers.

[Erik Botö (erik-boto)]

Hi,

Sorry for the lack of feedback!

I have tested the precise-proposed version of gstreamer0.10-pulseaudio and I can verify that is solves the crash we see with the vanilla version.

Cheers.

[Colin Watson (cjwatson)]

The verification of this Stable Release Update has completed successfully and the package has now been released to -updates. Subsequently, the Ubuntu Stable Release Updates Team is being unsubscribed and will not receive messages about this bug report. In the event that you encounter a regression using the package from -updates please report a new bug using ubuntu-bug and tag the bug report regression-update so we can easily find any regresssions.

[Launchpad Janitor (janitor)]

This bug was fixed in the package gst-plugins-good0.10 - 0.10.31-1ubuntu1.1

---------------
gst-plugins-good0.10 (0.10.31-1ubuntu1.1) precise-proposed; urgency=low

  * debian/patches/git_ring_buffer_null_check.patch: segfault fix,
    thanks Erik Botö for backporting and testing the change (lp: #1068155)
 -- Sebastien Bacher <email address hidden> Fri, 16 Nov 2012 12:51:49 +0100

[Launchpad Janitor (janitor)]

This bug was fixed in the package gst-plugins-good0.10 - 0.10.31-3ubuntu1.1

---------------
gst-plugins-good0.10 (0.10.31-3ubuntu1.1) quantal-proposed; urgency=low

  * debian/patches/git_ring_buffer_null_check.patch: segfault fix,
    thanks Erik Botö for backporting and testing the change (lp: #1068155)
 -- Sebastien Bacher <email address hidden> Fri, 16 Nov 2012 12:51:49 +0100