Issue Report

Bug

Container Linux Version

1618.0.0 and newer

Environment

qemu, possibly others

Expected Behavior

appending to the kernel command line via editing the grub menu does no prevent the system from booting.

Actual Behavior

Appending to the kernel command line prevents the system from booting. grub exits with the error message: free magic is broken at 0x3cec8166: 0xcfc53e26 (actual addresses vary)

Reproduction Steps

1. Build a Container Linux image
2. run the generated coreos_production_qemu.sh script
3. when the grub menu appears, edit the first entry and append something to the linux command like (e.g. "aaaaaaaaaaaaaaaaaaaaa")
4. Press ^X to boot
5. observe free magic is broken at... message

Other Information

This was introduced with changing /boot to fat32. It may be a bug in our image creation or in grub itself.

It is present with our current alpha images, and in master. Sometimes the error message is repeated, especially when building off master, although that is probably coincidence.