Having upgraded from TrueNAS Core 12.0-U1 to 12.0-U2, the system starts kernel panicking when there's HDD load of any kind (Scrubbing, copying files, etc.)
IBM X3650 M3,
IBM M1015 HBA (LSI 2008 chipset) connected to IBM SAS expander.
Debug logs attached.
Note: Reverting to 12.0-U1 fixed the issue and the system is stable again.