[Bug 1833479] Re: libjack-jackd2-0 double close on a failure to connect to jackd which causes crashes in multithreaded programs

[Joseph Yasi]

Can this package get updated to 1.9.13, or at least patched in time for
20.04? The security exploitability of this bug may be low, but the impact
on affected users is high. It causes hard to debug, random crashes of other
programs (e g. Kodi) that are scanning ALSA devices when the jack daemon
isn't even started.

On Wed, Nov 20, 2019, 10:40 PM Teeedubb <1833479 at bugs.launchpad.net>
wrote:

> Hi,
>
> I am experiencing the same issue with Kodi 18.5 and Xubuntu 19.10 with
> similar stack traces to joe-yasi. Is there anyway to install the updated
> package via Ubuntu updates?
>
> --
> You received this bug notification because you are subscribed to the bug
> report.
> https://bugs.launchpad.net/bugs/1833479
>
> Title:
>   libjack-jackd2-0 double close on a failure to connect to jackd which
>   causes crashes in multithreaded programs
>
> Status in jackd2 package in Ubuntu:
>   Confirmed
> Status in jackd2 package in Debian:
>   Confirmed
>
> Bug description:
>   After upgrading to Ubuntu 19.04, I started experiencing sporadic
>   crashes in kodi when turning my AV receiver on. Ubuntu 19.04 upgraded
>   alsa-plugins to 1.1.8. For alsa-plugins >= 1.1.7, the ALSA jack plugin
>   is enabled by default in /etc/alsa/conf.d/50-jack.conf.
>
>   The crashes are caused by a race condition when kodi's audio engine
>   thread is enumerating the ALSA sound devices, and the udev thread is
>   enumerating the udev devices triggered by the sound device add from
>   turning the AVR on.
>
>   When enumerating the ALSA jack plugin device, it tries to connect to
>   connect to jackd. Since I don't have jackd installed, it fails to
>   connect. libjack closes the socket on error, and then closes it again
>   in it's cleanup code. Since it's closing the same file descriptor
>   twice, it interacts with other threads that have potentially opened
>   file descriptors, and causes the crash.
>
>   This same bug could potentially affect other multi-threaded programs
>   that enumerate ALSA devices.
>
>   Fix committed upstream:
>
> https://github.com/jackaudio/jack2/commit/dad4b5702782eef3bd66e3c3f4fefaaae3571208
>
> To manage notifications about this bug go to:
>
> https://bugs.launchpad.net/ubuntu/+source/jackd2/+bug/1833479/+subscriptions
>

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https://bugs.launchpad.net/bugs/1833479

Title:
  libjack-jackd2-0 double close on a failure to connect to jackd which
  causes crashes in multithreaded programs

To manage notifications about this bug go to:
https://bugs.launchpad.net/ubuntu/+source/jackd2/+bug/1833479/+subscriptions