[alsa-devel] Assertion failure in alsa-lib crashing applications (snd_pcm_area_copy: Assertion `dst < src || dst >= src + bytes' failed)

[Baptiste Jonglez]

Hi,

When using Ring [1], an audio-video application, it sometimes crashes
because of an assertion in libasound.so:

    pcm.c:2758: snd_pcm_area_copy: Assertion `dst < src || dst >= src + bytes' failed.

The complete upstream bug report is at [2].  The (not-so-useful) stack
trace is the following:

#0  0x00007fc356e462a8 raise (libc.so.6)
#1  0x00007fc356e4772a abort (libc.so.6)
#2  0x00007fc356e3f1b7 __assert_fail_base (libc.so.6)
#3  0x00007fc356e3f262 __assert_fail (libc.so.6)
#4  0x00007fc35ba65c84 snd_pcm_area_copy (libasound.so.2)
#5  0x00007fc35ba65ebc snd_pcm_areas_copy (libasound.so.2)
#6  0x00007fc35baa6d95 n/a (libasound.so.2)
#7  0x00007fc35ba77c1f n/a (libasound.so.2)
#8  0x00007fc35ba77a59 n/a (libasound.so.2)
#9  0x000000000051ba97 n/a (dring)
#10 0x000000000051c118 n/a (dring)
#11 0x000000000051cfad n/a (dring)
#12 0x00007fc357787c40 execute_native_thread_routine (libstdc++.so.6)
#13 0x00007fc359ec2424 start_thread (libpthread.so.0)
#14 0x00007fc356efacbd __clone (libc.so.6)

The next time it crashes, I will have debug symbols in dring.  I can also
recompile alsa-lib with debug symbols, what is the best way to do that?

Looking around, it seems other projects have run into the same issue:

    https://aur.archlinux.org/packages/ultrastardx-git/?comments=all#comment-435458
    https://aur.archlinux.org/packages/zoom/#comment-544696
    http://ubuntuforums.org/showthread.php?t=2248373
    https://github.com/js-platform/node-webrtc/issues/110
    https://fedorahosted.org/fldigi/ticket/70

The output of the alsa-info.sh script on my system is at [3].
What else can I provide to debug this issue further?

Thanks,
Baptiste

[1] https://ring.cx
[2] https://tuleap.ring.cx/plugins/tracker/?aid=502
[3] http://www.alsa-project.org/db/?f=0dd2ba1021b3d535f30f07c55dc18e2ef60db26d
-------------- next part --------------
A non-text attachment was scrubbed...
Name: signature.asc
Type: application/pgp-signature
Size: 819 bytes
Desc: not available
URL: <http://mailman.alsa-project.org/pipermail/alsa-devel/attachments/20160607/7202e1de/attachment.sig>