With recent changes introduced for the "run as non-root" feature, some services now need to use /tmp as a temp folder (before, it was in the root user directory).
Everything works correctly when booting from a normal storage device (usb, sd-card, ...) on all platforms because systemd is responsible for mounting /tmp and /root and applies the correct smack label, as specified in the config fragment /lib/systemd/system/tmp.mount.d/smack.conf .
But when using netboot, the initrd script is responsible for mounting /tmp and /run before pivoting on new rootfs and running systemd. As a consequence, systemd doesn't try to remount /tmp or /run (and correct smack label is not applied).
I see 2 potential fixes ATM:
- make the initrd not mount /tmp or /run (or mount then umount them)
- make the initrd mount /tmp and /run as systemd usually does (with option 'smackfsroot=*')