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WARNING: CPU: 1 PID: 3344 at kernel/kthread.c:87 free_kthread_struct+0xa2/0xe0 kernel/kthread.c:87
Kernel panic - not syncing: panic_on_warn set ...

CPU: 1 PID: 3344 Comm: syz-executor7 Not tainted 4.14.0-rc3-mm1+ #14
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:181
 __warn+0x1c4/0x1e0 kernel/panic.c:544
 report_bug+0x211/0x2d0 lib/bug.c:183
 fixup_bug+0x40/0x90 arch/x86/kernel/traps.c:178
 do_trap_no_signal arch/x86/kernel/traps.c:212 [inline]
 do_trap+0x260/0x390 arch/x86/kernel/traps.c:261
 do_error_trap+0x120/0x390 arch/x86/kernel/traps.c:298
 do_invalid_op+0x1b/0x20 arch/x86/kernel/traps.c:311
 invalid_op+0x18/0x20 arch/x86/entry/entry_64.S:905
RIP: 0010:free_kthread_struct+0xa2/0xe0 kernel/kthread.c:87
RSP: 0000:ffff8801db307768 EFLAGS: 00010206
RAX: 0000000080000103 RBX: ffff8801c912f580 RCX: 1ffff1003b660ee1
RDX: ffff8801d13a6300 RSI: 0000000000000000 RDI: ffff8801c912f708
RBP: ffff8801db307770 R08: 0000000000000000 R09: 1ffff1003b660ed4
R10: ffff8801d13a6300 R11: 0000000000000005 R12: 1ffff1003b660ef0
R13: 1ffff1003b660ef4 R14: 0000000000000000 R15: ffff8801db3077e0
 free_task+0x134/0x1a0 kernel/fork.c:386
 __put_task_struct+0x229/0x3b0 kernel/fork.c:670
 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:195 [inline]
 rcu_do_batch kernel/rcu/tree.c:2758 [inline]
 invoke_rcu_callbacks kernel/rcu/tree.c:3012 [inline]
 __rcu_process_callbacks kernel/rcu/tree.c:2979 [inline]
 rcu_process_callbacks+0xd74/0x17d0 kernel/rcu/tree.c:2996
 __do_softirq+0x29d/0xbb2 kernel/softirq.c:284
 invoke_softirq kernel/softirq.c:364 [inline]
 irq_exit+0x1d3/0x210 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:1041
 apic_timer_interrupt+0x9d/0xb0 arch/x86/entry/entry_64.S:770
 </IRQ>
RIP: 0010:arch_local_irq_restore arch/x86/include/asm/paravirt.h:777 [inline]
RIP: 0010:lock_acquire+0x256/0x580 kernel/locking/lockdep.c:4005
RSP: 0000:ffff8801c87cefa8 EFLAGS: 00000286 ORIG_RAX: ffffffffffffff11
RAX: dffffc0000000000 RBX: ffff8801d13a6300 RCX: 0000000000000000
RDX: 1ffffffff0b5970d RSI: 0000000054a0b763 RDI: 0000000000000286
RBP: ffff8801c87cf0a0 R08: 0000000000000000 R09: 0000000000000001
R10: 0000000000000000 R11: ffffffff87069c60 R12: 1ffff100390f9dfb
R13: 0000000000000000 R14: 0000000000000002 R15: 0000000000000000
 rcu_lock_acquire include/linux/rcupdate.h:244 [inline]
 rcu_read_lock include/linux/rcupdate.h:631 [inline]
 lock_page_memcg+0x8f/0x3b0 mm/memcontrol.c:1650
 page_add_file_rmap+0xef/0xa90 mm/rmap.c:1184
 alloc_set_pte+0x836/0x1880 mm/memory.c:3416
 filemap_map_pages+0x1080/0x15d0 mm/filemap.c:2567
 do_fault_around mm/memory.c:3562 [inline]
 do_read_fault mm/memory.c:3596 [inline]
 do_fault mm/memory.c:3701 [inline]
 handle_pte_fault mm/memory.c:3931 [inline]
 __handle_mm_fault+0x1f57/0x39c0 mm/memory.c:4055
 handle_mm_fault+0x334/0x8d0 mm/memory.c:4092
 __do_page_fault+0x5bd/0xd60 arch/x86/mm/fault.c:1444
 do_page_fault+0xee/0x720 arch/x86/mm/fault.c:1520
 page_fault+0x22/0x30 arch/x86/entry/entry_64.S:1066
RIP: 0033:0x4055aa
RSP: 002b:0000000000a6f918 EFLAGS: 00010246
RAX: 0000000000760000 RBX: 00000000019d0914 RCX: 000000000040c380
RDX: 0000000000760008 RSI: 0000000000000000 RDI: 0000000000a6f970
RBP: 0000000000000000 R08: 0000000000000000 R09: 00000000019d0940
R10: 0000000000000000 R11: 0000000000000246 R12: 000000000000001c
R13: 0000000000000013 R14: 000000000000cf34 R15: 0000000000000016
Dumping ftrace buffer:
   (ftrace buffer empty)
Kernel Offset: disabled
Rebooting in 86400 seconds..