ModemManager crash with more than one call with Huawei E3131 Modem

[Aleksander Morgado]

Hey Enrico,

> > I am experiencing a crash in Modemmanager, triggered by the following scenario:
> > 1 - Start a voice call from mmcli to my mobile phone.
> > 2 - Answer the call there.
> > 3 - From the mobile phone, call back my Huawei E3131 device.
> >
> > This results in the following crash: let me know if I can help out more.
> >
>
> While I could write a quick fix for this issue, just replacing a
> g_assert() by a if() check, I do need to understand fully how the
> situation happened, because I did really expect the g_assert() to
> always succeed. Will let you know.
>

I've understood how it happened, and the fix is indeed just to change
the assert with an if(), because it really is an expected usecase.

The problem happened because in load_call_list_ready() we call
mm_iface_modem_voice_report_all_calls() before the assert() was
checked, and in that report_all_calls() method we may be detecting new
incoming calls that would trigger setting the call polling timeout as
well.

I've pushed a new fix for this already that will get to git master
soon and then I'll backport it to the 1.12.x branch:
https://gitlab.freedesktop.org/mobile-broadband/ModemManager/-/merge_requests/284

These are the relevant commits from your log:

ModemManager[417212]: <debug> [1589977056.106485] 1 calls being
established: call list polling required

    ctx->polling_ongoing = TRUE;
    load_call_list()
    load_call_list_ready()
    ctx->polling_ongoing = FALSE;

ModemManager[417212]: <debug> [1589977056.106550] (ttyUSB2) device
open count is 3 (open)
ModemManager[417212]: <debug> [1589977056.106624] (ttyUSB2): --> 'AT+CLCC<CR>'
ModemManager[417212]: <debug> [1589977056.116273] (ttyUSB2): <--
'<CR><LF>+CLCC: 1,0,0,0,0,"39XXXX",145,"",<CR><LF>+CLCC:
2,1,5,0,0,"39XXXX",145,"",<CR><LF><CR><LF>OK<CR><LF>'

    mm_iface_modem_voice_report_all_calls()

        New call added, setup_call_list_polling() is executed, which
ends up setting up the call_list_poll() timeout.

ModemManager[417212]: <debug> [1589977056.116495] Reported 2 ongoing calls
ModemManager[417212]: <debug> [1589977056.116516] call at index 1:
direction outgoing, state active, number 39XXXX
ModemManager[417212]: <debug> [1589977056.116525] call at index 2:
direction incoming, state waiting, number 39XXXX
ModemManager[417212]: <debug> [1589977056.116550] call info matched
(matched direction/state no, matched number yes, matched index no,
matched terminated no) with call at
'/org/freedesktop/ModemManager1/Call/1'
ModemManager[417212]: <debug> [1589977056.116566]   index set: 1
ModemManager[417212]: <debug> [1589977056.116578]   state updated: active
ModemManager[417212]: <info>  [1589977056.116590] Call state changed:
waiting -> active (unknown)
ModemManager[417212]: <debug> [1589977056.116727]   incoming refreshed
ModemManager[417212]: <debug> [1589977056.116750] Call
'/org/freedesktop/ModemManager1/Call/0' with direction outgoing, state
active, number '+39XXXX', index 1 not found in list, terminating
ModemManager[417212]: <info>  [1589977056.116767] Call state changed:
active -> terminated (unknown)

ModemManager[417212]: <debug> [1589977056.116868] Creating new incoming call...
ModemManager[417212]: <info>  [1589977056.116972] Call state changed:
unknown -> waiting (incoming-new)
ModemManager[417212]: <debug> [1589977056.117054] Added call at
'/org/freedesktop/ModemManager1/Call/2'
**
ERROR:mm-iface-modem-voice.c:2376:load_call_list_ready: assertion
failed: (!ctx->polling_id)
Bail out! ERROR:mm-iface-modem-voice.c:2376:load_call_list_ready:
assertion failed: (!ctx->polling_id)


-- 
Aleksander
https://aleksander.es