======================================
| [ 1672.798661][    C1] page dumped because: VM_BUG_ON_PAGE(page_ref_count(page) == 0)
| [ 1672.798895][    C1] ------------[ cut here ]------------
| [ 1672.799046][    C1] kernel BUG at include/linux/mm.h:1140!
| [ 1672.799211][    C1] Oops: invalid opcode: 0000 [#1] PREEMPT SMP KASAN NOPTI
[ 1672.799599][    C1] Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS rel-1.16.3-0-ga6ed6b701f0a-prebuilt.qemu.org 04/01/2014
[ 1672.799885][ C1] RIP: 0010:__free_pages (./include/linux/mm.h:1140 ./include/linux/mm.h:1138 mm/page_alloc.c:4819) 
[ 1672.800030][ C1] Code: 0f 94 c3 e9 ba fe ff ff 48 c7 c6 a0 18 58 b7 4c 89 e7 e8 df bf f4 ff 90 0f 0b 48 c7 c6 40 29 58 b7 4c 89 e7 e8 cd bf f4 ff 90 <0f> 0b 48 89 ef e8 72 03 09 00 e9 c5 fe ff ff e8 98 03 09 00 e9 35
All code
========
   0:	0f 94 c3             	sete   %bl
   3:	e9 ba fe ff ff       	jmp    0xfffffffffffffec2
   8:	48 c7 c6 a0 18 58 b7 	mov    $0xffffffffb75818a0,%rsi
   f:	4c 89 e7             	mov    %r12,%rdi
  12:	e8 df bf f4 ff       	call   0xfffffffffff4bff6
  17:	90                   	nop
  18:	0f 0b                	ud2
  1a:	48 c7 c6 40 29 58 b7 	mov    $0xffffffffb7582940,%rsi
  21:	4c 89 e7             	mov    %r12,%rdi
  24:	e8 cd bf f4 ff       	call   0xfffffffffff4bff6
  29:	90                   	nop
  2a:*	0f 0b                	ud2		<-- trapping instruction
  2c:	48 89 ef             	mov    %rbp,%rdi
  2f:	e8 72 03 09 00       	call   0x903a6
  34:	e9 c5 fe ff ff       	jmp    0xfffffffffffffefe
  39:	e8 98 03 09 00       	call   0x903d6
  3e:	e9                   	.byte 0xe9
  3f:	35                   	.byte 0x35

Code starting with the faulting instruction
===========================================
   0:	0f 0b                	ud2
   2:	48 89 ef             	mov    %rbp,%rdi
   5:	e8 72 03 09 00       	call   0x9037c
   a:	e9 c5 fe ff ff       	jmp    0xfffffffffffffed4
   f:	e8 98 03 09 00       	call   0x903ac
  14:	e9                   	.byte 0xe9
  15:	35                   	.byte 0x35
[ 1672.800487][    C1] RSP: 0018:ffffc900001bfcb0 EFLAGS: 00010246
[ 1672.800650][    C1] RAX: 000000000000003e RBX: 0000000000000000 RCX: 1ffffffff703b43c
[ 1672.800844][    C1] RDX: 0000000000000000 RSI: 0000000000000004 RDI: 0000000000000001
[ 1672.801037][    C1] RBP: ffffea0000076874 R08: 0000000000000000 R09: fffffbfff703b43c
[ 1672.801233][    C1] R10: 0000000000000003 R11: 205d314320202020 R12: ffffea0000076840
[ 1672.801420][    C1] R13: ffffc900001bfd78 R14: 0000000000000000 R15: 0000000000000008
[ 1672.801609][    C1] FS:  0000000000000000(0000) GS:ffff888036080000(0000) knlGS:0000000000000000
[ 1672.801822][    C1] CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
[ 1672.801982][    C1] CR2: 00007ffcd1921000 CR3: 0000000007cae001 CR4: 0000000000772ef0
[ 1672.802173][    C1] DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
[ 1672.802373][    C1] DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400
[ 1672.802567][    C1] PKRU: 55555554
[ 1672.802665][    C1] Call Trace:
[ 1672.802761][    C1]  <TASK>
[ 1672.802844][ C1] ? die (arch/x86/kernel/dumpstack.c:421 arch/x86/kernel/dumpstack.c:434 arch/x86/kernel/dumpstack.c:447) 
[ 1672.802947][ C1] ? do_trap (arch/x86/kernel/traps.c:156 arch/x86/kernel/traps.c:197) 
[ 1672.803043][ C1] ? __free_pages (./include/linux/mm.h:1140 ./include/linux/mm.h:1138 mm/page_alloc.c:4819) 
[ 1672.803170][ C1] ? do_error_trap (./arch/x86/include/asm/traps.h:58 arch/x86/kernel/traps.c:218) 
[ 1672.803294][ C1] ? __free_pages (./include/linux/mm.h:1140 ./include/linux/mm.h:1138 mm/page_alloc.c:4819) 
[ 1672.803415][ C1] ? __free_pages (./include/linux/mm.h:1140 ./include/linux/mm.h:1138 mm/page_alloc.c:4819) 
[ 1672.803537][ C1] ? handle_invalid_op (arch/x86/kernel/traps.c:256) 
[ 1672.803660][ C1] ? __free_pages (./include/linux/mm.h:1140 ./include/linux/mm.h:1138 mm/page_alloc.c:4819) 
[ 1672.803783][ C1] ? exc_invalid_op (arch/x86/kernel/traps.c:315) 
[ 1672.803906][ C1] ? asm_exc_invalid_op (./arch/x86/include/asm/idtentry.h:621) 
[ 1672.804037][ C1] ? __free_pages (./include/linux/mm.h:1140 ./include/linux/mm.h:1138 mm/page_alloc.c:4819) 
[ 1672.804169][ C1] ? rcu_do_batch (kernel/rcu/tree.c:2567) 
[ 1672.804295][ C1] neigh_hash_free_rcu (net/core/neighbour.c:555) 
[ 1672.804423][ C1] rcu_do_batch (kernel/rcu/tree.c:2567) 
[ 1672.804545][ C1] ? __pfx___lock_release (kernel/locking/lockdep.c:5477) 
[ 1672.804673][ C1] ? __pfx_rcu_do_batch (kernel/rcu/tree.c:2491) 
[ 1672.804795][ C1] ? lockdep_hardirqs_on_prepare (kernel/locking/lockdep.c:4339 kernel/locking/lockdep.c:4406) 
[ 1672.804951][ C1] rcu_core (kernel/rcu/tree.c:2825) 
[ 1672.805051][ C1] handle_softirqs (kernel/softirq.c:554) 
[ 1672.805179][ C1] ? __pfx_run_ksoftirqd (kernel/softirq.c:920) 
[ 1672.805302][ C1] run_ksoftirqd (kernel/softirq.c:411 kernel/softirq.c:928 kernel/softirq.c:919) 
[ 1672.805428][ C1] smpboot_thread_fn (kernel/smpboot.c:164 (discriminator 3)) 
[ 1672.805554][ C1] ? __pfx_smpboot_thread_fn (kernel/smpboot.c:107) 
[ 1672.805678][ C1] ? __pfx_smpboot_thread_fn (kernel/smpboot.c:107) 
[ 1672.805799][ C1] kthread (kernel/kthread.c:389) 
[ 1672.805895][ C1] ? __pfx_kthread (kernel/kthread.c:342) 
[ 1672.806018][ C1] ret_from_fork (arch/x86/kernel/process.c:147) 
[ 1672.806150][ C1] ? __pfx_kthread (kernel/kthread.c:342) 


Finger prints:
__free_pages:neigh_hash_free_rcu:rcu_do_batch:rcu_core:handle_softirqs