Please enable debug logging, restart the 'rbd-mirror' daemon, and provide the resulting logs:

# ceph --cluster local set client.local debug_rbd 20
# ceph --cluster local set client.local debug_rbd_mirror 20

I don't require the mon logs.

Are there any additional logs from the rbd-mirror daemon client? I don't see any "librbd"-prefixed log messages in the provided log and the crash is in librbd. I would expect lots of log files in "/var/log/ceph/" with names like "local.client.local.<pid>.<cctid>.log". You can force all the logs to the same file by running the following and restarting the daemon:

# ceph --cluster local set client.local log_file /var/log/ceph/local.client.local.log

If you are getting the logs via some stdout/stderr scraping process instead of via log files within the container, you will need to enable librbd logging to stderr:

# ceph --cluster local set client.local log_to_stderr true

Since the problem described in this bug report should be
resolved in a recent advisory, it has been closed with a
resolution of ERRATA.

For information on the advisory, and where to find the updated
files, follow the link below.

If the solution does not work for you, open a new bug report.

https://access.redhat.com/errata/RHBA-2020:0312