Samsung has suggested that this issue is being triggered by the samsung-laptop kernel module. This module is known to cause other issues on Samsung systems when booted in EFI mode:
Kernel team: is it possible to disable the samsung-laptop module when booted under EFI mode? Obviously this would have to be done at module load time; but that may be the best workaround until upstream is able to fix the module to stop tickling the firmware bug. I would prefer for us not to have to disable the samsung-laptop module entirely to work around this, since that would cause regressions for users who have Ubuntu working fine on their systems already in BIOS mode.