Bug#1033740: linphone crashed when receiving a phone call

[Dennis Filder]

X-Debbugs-Cc: Marco d'Itri <md at linux.it>

On Sat, Apr 01, 2023 at 11:53:32PM +0200, Marco d'Itri wrote:
> On Apr 01, Dennis Filder <d.filder at web.de> wrote:
>
> > I cannot reproduce this here.  BTW: That stack backtrace is missing
> > the actual error message which I need.
> I do not understand which message that would be: I reported the complete
> output of "where".
> If it is linphone output then I do not have it anymore: I only have the
> core dump.
>
> > The offending line in mediastreamer2 would be this:
> >
> >       s->dev = ms_strdup(card_data->pa_id_sink);
> >
> > In GDB, could you try running these commands after triggering the bug
> > and paste the output?
> >
> >   print s
> >   print *card_data
> (gdb)   print s
> $1 = (Stream *) 0x0
> (gdb)   print *card_data
> $2 = {pa_id_sink = 0x558b0c991820 "alsa_output.pci-0000_33_00.1.pro-output-3",
>   pa_id_source = 0x0}
> (gdb)

Okay, in your case s is NULL, so this is a null pointer dereference,
but that can only happen when pulse_write_init() returns early due to
not being able to connect to a pulseaudio server.

> > The output of "pactl list" could also help shed some light on the
> > cause.  It could be that you have a somewhat unusual pulseaudio setup.
> Actually I switched to pipewire and wireplumber.
> Also, I cannot promise that the current configuration that I am showing
> here is identical to the one at the time of the crash.

> Card #218
> ...
> Card #219
> ...
> Card #220

That this involves pipewire makes this issue rather difficult since
I'm not really familiar with it yet.  And it also means I can't really
try to reproduce it in a chroot and would have to do it on bare metal.

These unusually high card IDs strike me as very odd.  Do they change
over the duration of a session?  I somewhat suspect pipewire keeps
reconstructing its pulseaudio facility on-the-fly, and that might be
too slow for what pulse_write_init() is expecting.  But I'm just
guessing here.

It would help a lot if you launched something that talks to pulseaudio
continuously (e.g. pavucontrol) before launching linphone.  This would
ensure that the pulseaudio backend is already up and stays up.  Can
you still reproduce the crash then?  And can you play the selected
ringtone under Menu -> Preferences -> Audio?

Regards