WARNING: CPU: 0 PID: 4918 at kernel/kthread.c:87 free_kthread_struct+0xa2/0xe0 kernel/kthread.c:87
Kernel panic - not syncing: panic_on_warn set ...

CPU: 0 PID: 4918 Comm: modprobe Not tainted 4.14.0-rc5-mm1+ #20
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011
Call Trace:
 <IRQ>
 __dump_stack lib/dump_stack.c:16 [inline]
 dump_stack+0x194/0x257 lib/dump_stack.c:52
 panic+0x1e4/0x41c kernel/panic.c:183
 __warn+0x1c4/0x1e0 kernel/panic.c:546
 report_bug+0x211/0x2d0 lib/bug.c:183
 fixup_bug+0x40/0x90 arch/x86/kernel/traps.c:177
 do_trap_no_signal arch/x86/kernel/traps.c:211 [inline]
 do_trap+0x260/0x390 arch/x86/kernel/traps.c:260
 do_error_trap+0x120/0x390 arch/x86/kernel/traps.c:297
 do_invalid_op+0x1b/0x20 arch/x86/kernel/traps.c:310
 invalid_op+0x18/0x20 arch/x86/entry/entry_64.S:905
RIP: 0010:free_kthread_struct+0xa2/0xe0 kernel/kthread.c:87
RSP: 0000:ffff8801db207768 EFLAGS: 00010206
RAX: ffff8801c431e680 RBX: ffff8801c548f400 RCX: ffffffff8148d7e2
RDX: 0000000000000100 RSI: 0000000000000000 RDI: ffff8801c548f4b8
RBP: ffff8801db207770 R08: 0000000000000001 R09: 1ffff1003b640edc
R10: ffff8801db2076a8 R11: 0000000000000004 R12: 1ffff1003b640ef0
R13: 1ffff1003b640ef4 R14: 0000000000000000 R15: ffff8801db2077e0
 free_task+0x134/0x1a0 kernel/fork.c:390
 __put_task_struct+0x229/0x3b0 kernel/fork.c:668
 put_task_struct include/linux/sched/task.h:95 [inline]
 delayed_put_task_struct+0xca/0x3d0 kernel/exit.c:180
 __rcu_reclaim kernel/rcu/rcu.h:172 [inline]
 rcu_do_batch kernel/rcu/tree.c:2676 [inline]
 invoke_rcu_callbacks kernel/rcu/tree.c:2930 [inline]
 __rcu_process_callbacks kernel/rcu/tree.c:2897 [inline]
 rcu_process_callbacks+0xd74/0x17d0 kernel/rcu/tree.c:2914
 __do_softirq+0x2d7/0xb85 kernel/softirq.c:284
 invoke_softirq kernel/softirq.c:364 [inline]
 irq_exit+0x1cc/0x200 kernel/softirq.c:405
 exiting_irq arch/x86/include/asm/apic.h:540 [inline]
 smp_apic_timer_interrupt+0x16b/0x700 arch/x86/kernel/apic/apic.c:1052
 apic_timer_interrupt+0x9d/0xb0 arch/x86/entry/entry_64.S:770
 </IRQ>
RIP: 0010:__read_once_size include/linux/compiler.h:276 [inline]
RIP: 0010:compound_head include/linux/page-flags.h:146 [inline]
RIP: 0010:PageSwapBacked include/linux/page-flags.h:287 [inline]
RIP: 0010:mm_counter_file include/linux/mm.h:1522 [inline]
RIP: 0010:alloc_set_pte+0x71a/0x1880 mm/memory.c:3420
RSP: 0000:ffff8801c402f3e0 EFLAGS: 00000246 ORIG_RAX: ffffffffffffff11
RAX: dffffc0000000000 RBX: ffff8801c402fb80 RCX: ffffffff81987189
RDX: 1ffff10038805e98 RSI: ffffea00076cb000 RDI: ffffea00076cb020
RBP: ffff8801c402f528 R08: 0000000000000001 R09: 1ffff10038805e0a
R10: ffff8801c402ef88 R11: 0000000000000003 R12: 1ffff10038805e84
R13: 1ffff10038805e98 R14: 0000000000000025 R15: ffffea00076cafe0
 filemap_map_pages+0x1080/0x15d0 mm/filemap.c:2680
 do_fault_around mm/memory.c:3567 [inline]
 do_read_fault mm/memory.c:3601 [inline]
 do_fault mm/memory.c:3706 [inline]
 handle_pte_fault mm/memory.c:3936 [inline]
 __handle_mm_fault+0x1f57/0x39c0 mm/memory.c:4060
 handle_mm_fault+0x334/0x8d0 mm/memory.c:4097
 __do_page_fault+0x5bd/0xd60 arch/x86/mm/fault.c:1438
 do_page_fault+0xee/0x720 arch/x86/mm/fault.c:1514
 page_fault+0x22/0x30 arch/x86/entry/entry_64.S:1066
RIP: 0033:0x7fe25f595390
RSP: 002b:00007ffeb59a5f08 EFLAGS: 00010202
RAX: 0000000000000000 RBX: 00007ffeb59a72a8 RCX: 0000563871b59660
RDX: 00005638719547f0 RSI: 00007ffeb59a72a8 RDI: 0000000000000004
RBP: 00007ffeb59a72a8 R08: 00007ffeb59a5f7c R09: 0000000000000000
R10: 0000000000000000 R11: 00007fe25f595390 R12: 0000000000000004
R13: 0000563871954608 R14: 0000000000000000 R15: 0000000000000000
Dumping ftrace buffer:
   (ftrace buffer empty)
Kernel Offset: disabled
Rebooting in 86400 seconds..