wvdial crashes after upgrade to bionic 18.04

[Janne Snabb]

Since upgrading Ubuntu from 17.10 to 18.04 wvdial is crashing with the following error message when connection is established:

# wvdial 3gconnect
--> WvDial: Internet dialer version 1.61
--> Initializing modem.
--> Sending: ATZ
ATZ
OK
--> Sending: ATQ0 V1 E1 S0=0 &C1 &D2 +FCLASS=0
ATQ0 V1 E1 S0=0 &C1 &D2 +FCLASS=0
OK
--> Sending: AT+CGDCONT=1,"IP","internet"
AT+CGDCONT=1,"IP","internet"
OK
--> Modem initialized.
--> Sending: ATDT*99#
--> Waiting for carrier.
ATDT*99#
CONNECT 21000000
--> Carrier detected. Starting PPP immediately.
--> Starting pppd at Sun Apr 8 18:50:07 2018
--> Pid of pppd: 7400
wvdial: utils/wvtask.cc:303: static int WvTaskMan::yield(int): Assertion `*current_task->stack_magic == WVTASK_MAGIC' failed.
Aborted (core dumped)

The connection is still established. It happens after pppd is already started.

On 17.10 I did not encounter this issue.

Package version:

$ apt policy wvdial
wvdial:
  Installed: 1.61-4.1build1
  Candidate: 1.61-4.1build1
  Version table:
 *** 1.61-4.1build1 500
        500 http://se.archive.ubuntu.com/ubuntu bionic/universe amd64 Packages
        100 /var/lib/dpkg/status

It happens also on Debian. See the following for more details: https://bugs.debian.org/cgi-bin/bugreport.cgi?bug=863039

[Janne Snabb (snabb)]

It appears that the crash does not happen any more even though the wvdial package version remains the same as before. Possibly some condition has changed, not sure what (library versions is one possibility).

[Janne Snabb (snabb)]

After disappearing for a while, the problem re-appeared.

Luckily the bug is now fixed in Debian. The fix will eventually land in a future Ubuntu version.

[simone-c (simone-c)]

This is still reproducible in Bionic 18.04, but not on the latest Focal 20.04