Trying to format an iso onto usb using Gnome Disks, errors, I assume it is grsec, but have not confirmed by testing outside grsec kernel. But can format just fine from the command prompt.
See screenshot for error:
See command prompt for success:
todd@librem-13:~$ sudo mkdosfs -n "PureOS-3.0-beta" -I /dev/sdc -F 32 mkfs.fat 4.1 (2017-01-24) mkfs.fat: warning - lowercase labels might not work properly with DOS or Windows attribute "partition" not found todd@librem-13:~$ sudo dd if=Downloads/pureos-3.0~beta1-live-amd64.hybrid.iso of=/dev/sdc bs=4k 316992+0 records in 316992+0 records out 1298399232 bytes (1.3 GB, 1.2 GiB) copied, 230.051 s, 5.6 MB/s todd@librem-13:~$ sudo sync todd@librem-13:~$ sudo eject /dev/sdc todd@librem-13:~$