mdadm scan causes update-initramfs to hang

Kernel update requiring rebuild of initramfs. mdadm scans ALL devices including CDROM device. Disk in CDROM drive was unreadable. Scanning for RAID10 causes mdadm to hang forever. 24 hours later, still hung. Killing the process in the console leaves unkillable mdadm process forever hung and un-killable - kill -9, -KILL, -SIGKILL have no effect. Removing bad CDROM does not help as the mdadm process is still running preventing dpkg --configure -a from completing the initramfs build. Further, the hung mdadm scan also causes reboot to hang. Only exit is hard reset.

Rebooting to an older kernel allows dpkg --configure -a to finish.

Granted the conditions causing this are esoteric but possible nonetheless.

It seems illogical that mdadm is scanning CDROM (srX) devices as I doubt one could build a RAID 10 device using CDROMs.

Perhaps configuring /usr/share/mdadm/mkconf to skip srX devices is possible?

mdadm --version
mdadm - v4.2 - 2021-12-30

uname -provism
Linux 5.19.0-46-generic #47~22.04.1-Ubuntu SMP PREEMPT_DYNAMIC Wed Jun 21 15:35:31 UTC 2 x86_64 x86_64 x86_64 GNU/Linux