Kernel Panic on CentOS - Google Compute Engine Instance

I'm getting a kernel panic error in a CentOS instance of Google Compute Engine. I'm able to see the error and already figure out how to solve it, but I can't get into the GRUB menu trough the serial console. dracut: Mounted root filesystem /dev/sda1 dracut: Loading SELinux policy type=1404 audit(1479929075.614:2): enforcing=1 old_enforcing=0 auid=4294967295 ses=4294967295 dracut: SELinux: Could not open policy file ] ? panic+0xa7/0x179 [] ? perf_event_exit_task+0xc0/0x340 [] ? do_exit+0x867/0x870 [] ? fput+0x25/0x30 [] ? do_group_exit+0x58/0xd0 [] ? sys_exit_group+0x17/0x20 [] ? system_call_fastpath+0x16/0x1b The CentOS version is 6.7 and this happened after a yum update. I'm just trying to get into GRUBs menu to append "selinux=0" to boot into Permissive mode, but it seems that it's not possible through the serial console. I would appreciate any help.