Using a serial console or netconsole , capture the full kernel panic. Look for lines immediately preceding it:
This extends Secure Boot. The bootloader verifies the kernel and initramfs signatures. Then, the kernel uses dm-verity to verify the root filesystem. The knewrootfsverificationerror typically appears when the kernel finds the dm-verity signature attached to the initramfs but fails to validate it. knewrootfsverificationerror