Comment 11 for bug 1684295

I think the best way forward here is to get a core dump, so we can have a better idea of where the crash is happening.

I induced a crash in my test sssd container, and since I have apport installed, a crash file was produced in /var/crash:
# ll /var/crash/
total 644
drwxrwxrwt 2 root root 4 Nov 1 20:34 ./
drwxr-xr-x 13 root root 15 Sep 19 19:18 ../
-rwxr-xr-x 1 root root 0 Nov 1 20:34 .lock*
-rw-r----- 1 root root 593417 Nov 1 20:34 _usr_lib_x86_64-linux-gnu_sssd_sssd_be.0.crash

Could you please check if you have a recent crash file related to sssd in that directory.

If not, do this:
sudo apt install apport

# check the kernel core_pattern:

# sysctl kernel.core_pattern
kernel.core_pattern = |/usr/share/apport/apport %p %s %c %P

And then restart sssd and induce the crash again, and then hopefully you will have a crash file and we can go from there.