======================================
| [  529.825526][    C1] page dumped because: VM_BUG_ON_PAGE(page_ref_count(page) == 0)
| [  529.825831][    C1] ------------[ cut here ]------------
| [  529.826053][    C1] kernel BUG at include/linux/mm.h:1140!
| [  529.826237][    C1] Oops: invalid opcode: 0000 [#1] PREEMPT SMP KASAN NOPTI
[  529.826695][    C1] Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS rel-1.16.3-0-ga6ed6b701f0a-prebuilt.qemu.org 04/01/2014
[ 529.827016][ C1] RIP: 0010:__free_pages (./include/linux/mm.h:1140 ./include/linux/mm.h:1138 mm/page_alloc.c:4819) 
[ 529.827178][ C1] Code: 0f 94 c3 e9 ba fe ff ff 48 c7 c6 a0 18 78 ba 4c 89 e7 e8 df bf f4 ff 90 0f 0b 48 c7 c6 40 29 78 ba 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 78 ba 	mov    $0xffffffffba7818a0,%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 78 ba 	mov    $0xffffffffba782940,%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
[  529.827671][    C1] RSP: 0018:ffffc900001e8e08 EFLAGS: 00010246
[  529.827861][    C1] RAX: 000000000000003e RBX: 0000000000000000 RCX: 1ffffffff767b43c
[  529.828069][    C1] RDX: 0000000000000000 RSI: 0000000000000004 RDI: 0000000000000001
[  529.828275][    C1] RBP: ffffea0000178134 R08: 0000000000000000 R09: fffffbfff767b43c
[  529.828486][    C1] R10: 0000000000000003 R11: 205d314320202020 R12: ffffea0000178100
[  529.828693][    C1] R13: ffffc900001e8ed0 R14: 0000000000000000 R15: 0000000000000008
[  529.828902][    C1] FS:  00007f3e5b5a9740(0000) GS:ffff888036080000(0000) knlGS:0000000000000000
[  529.829145][    C1] CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
[  529.829325][    C1] CR2: 00007f3e5ba1b270 CR3: 0000000009ba0004 CR4: 0000000000772ef0
[  529.829535][    C1] DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
[  529.829746][    C1] DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400
[  529.829961][    C1] PKRU: 55555554
[  529.830070][    C1] Call Trace:
[  529.830174][    C1]  <IRQ>
[ 529.830251][ C1] ? die (arch/x86/kernel/dumpstack.c:421 arch/x86/kernel/dumpstack.c:434 arch/x86/kernel/dumpstack.c:447) 
[ 529.830364][ C1] ? do_trap (arch/x86/kernel/traps.c:156 arch/x86/kernel/traps.c:197) 
[ 529.830475][ C1] ? __free_pages (./include/linux/mm.h:1140 ./include/linux/mm.h:1138 mm/page_alloc.c:4819) 
[ 529.830679][ C1] ? do_error_trap (./arch/x86/include/asm/traps.h:58 arch/x86/kernel/traps.c:218) 
[ 529.830844][ C1] ? __free_pages (./include/linux/mm.h:1140 ./include/linux/mm.h:1138 mm/page_alloc.c:4819) 
[ 529.830984][ C1] ? __free_pages (./include/linux/mm.h:1140 ./include/linux/mm.h:1138 mm/page_alloc.c:4819) 
[ 529.831133][ C1] ? handle_invalid_op (arch/x86/kernel/traps.c:256) 
[ 529.831272][ C1] ? __free_pages (./include/linux/mm.h:1140 ./include/linux/mm.h:1138 mm/page_alloc.c:4819) 
[ 529.831412][ C1] ? exc_invalid_op (arch/x86/kernel/traps.c:315) 
[ 529.831555][ C1] ? asm_exc_invalid_op (./arch/x86/include/asm/idtentry.h:621) 
[ 529.831702][ C1] ? __free_pages (./include/linux/mm.h:1140 ./include/linux/mm.h:1138 mm/page_alloc.c:4819) 
[ 529.831845][ C1] ? __free_pages (./include/linux/mm.h:1140 ./include/linux/mm.h:1138 mm/page_alloc.c:4819) 
[ 529.831983][ C1] ? rcu_do_batch (kernel/rcu/tree.c:2567) 
[ 529.832135][ C1] neigh_hash_free_rcu (net/core/neighbour.c:554) 
[ 529.832280][ C1] rcu_do_batch (kernel/rcu/tree.c:2567) 
[ 529.832420][ C1] ? __pfx_rcu_do_batch (kernel/rcu/tree.c:2491) 
[ 529.832571][ C1] ? lockdep_hardirqs_on_prepare (kernel/locking/lockdep.c:4339 kernel/locking/lockdep.c:4406) 
[ 529.832747][ C1] rcu_core (kernel/rcu/tree.c:2825) 
[ 529.832856][ C1] handle_softirqs (kernel/softirq.c:554) 
[ 529.832997][ C1] ? __dev_queue_xmit (./include/linux/rcupdate.h:347 ./include/linux/rcupdate.h:917 net/core/dev.c:4457) 
[ 529.833148][ C1] do_softirq (kernel/softirq.c:455 kernel/softirq.c:442) 
[  529.833260][    C1]  </IRQ>
[  529.833336][    C1]  <TASK>
[ 529.833415][ C1] __local_bh_enable_ip (kernel/softirq.c:382) 
[ 529.833570][ C1] ? __dev_queue_xmit (./include/linux/rcupdate.h:347 ./include/linux/rcupdate.h:917 net/core/dev.c:4457) 
[ 529.833715][ C1] __dev_queue_xmit (net/core/dev.c:4458) 
[ 529.833860][ C1] ? __lock_release (kernel/locking/lockdep.c:5501) 
[ 529.834002][ C1] ? ip_finish_output2 (./include/net/neighbour.h:535 net/ipv4/ip_output.c:235) 
[ 529.834139][ C1] ? __pfx___lock_release (kernel/locking/lockdep.c:5477) 
[ 529.834280][ C1] ? __pfx_lock_acquire.part.0 (kernel/locking/lockdep.c:5790) 
[ 529.834442][ C1] ? __pfx___dev_queue_xmit (net/core/dev.c:4339) 
[ 529.834580][ C1] ? lockdep_hardirqs_on_prepare (kernel/locking/lockdep.c:4347 kernel/locking/lockdep.c:4406) 
[ 529.834774][ C1] ? neigh_hh_output (./include/linux/seqlock.h:74 ./include/linux/seqlock.h:757 ./include/net/neighbour.h:491) 
[ 529.834914][ C1] ip_finish_output2 (./include/net/neighbour.h:535 net/ipv4/ip_output.c:235) 
[ 529.835055][ C1] ? __pfx_ip_finish_output2 (net/ipv4/ip_output.c:199) 
[ 529.835192][ C1] ? __ip_finish_output (./include/linux/skbuff.h:1672 ./include/linux/skbuff.h:5019 net/ipv4/ip_output.c:307 net/ipv4/ip_output.c:295) 
[ 529.835332][ C1] ip_output (./include/linux/netfilter.h:303 net/ipv4/ip_output.c:433) 
[ 529.835434][ C1] ? __pfx_lock_acquire.part.0 (kernel/locking/lockdep.c:5790) 
[ 529.835570][ C1] ? __pfx_ip_output (net/ipv4/ip_output.c:427) 
[ 529.835708][ C1] ? lock_acquire (kernel/locking/lockdep.c:5798) 
[ 529.835856][ C1] ? lockdep_hardirqs_on_prepare (kernel/locking/lockdep.c:4347 kernel/locking/lockdep.c:4406) 
[ 529.836030][ C1] NF_HOOK.constprop.0 (./include/linux/skbuff.h:1672 ./include/linux/skbuff.h:5069 net/ipv4/ip_forward.c:99) 
[ 529.836170][ C1] ? __pfx_NF_HOOK.constprop.0 (./include/linux/netfilter.h:308) 
[ 529.836308][ C1] ? __get_random_u32_below (drivers/char/random.c:578) 
[ 529.836451][ C1] ? __ip_select_ident (./arch/x86/include/asm/atomic.h:85 ./include/linux/atomic/atomic-arch-fallback.h:564 ./include/linux/atomic/atomic-instrumented.h:124 net/ipv4/route.c:478 net/ipv4/route.c:494) 
[ 529.836592][ C1] raw_send_hdrinc (net/ipv4/raw.c:415) 
[ 529.836733][ C1] ? __pfx_raw_send_hdrinc (net/ipv4/raw.c:330) 
[ 529.836899][ C1] raw_sendmsg (net/ipv4/raw.c:644) 
[ 529.837083][ C1] ? __pfx_raw_sendmsg (net/ipv4/raw.c:483) 
[ 529.837390][ C1] ? usage_skip (kernel/locking/lockdep.c:2314 kernel/locking/lockdep.c:2282) 
[ 529.837531][ C1] ? __lock_release (kernel/locking/lockdep.c:5501) 
[ 529.837667][ C1] ? __might_fault (mm/memory.c:6700 mm/memory.c:6693) 
[ 529.837807][ C1] ? __pfx___lock_release (kernel/locking/lockdep.c:5477) 
[ 529.838024][ C1] ? trace_lock_acquire (./include/trace/events/lock.h:24 (discriminator 52)) 
[ 529.838168][ C1] ? __might_fault (mm/memory.c:6700 mm/memory.c:6693) 
[ 529.838304][ C1] ? lock_acquire (kernel/locking/lockdep.c:5798) 
[ 529.838444][ C1] ? __might_fault (mm/memory.c:6700 mm/memory.c:6693) 
[ 529.838665][ C1] ? __might_fault (mm/memory.c:6700 mm/memory.c:6693) 
[ 529.838804][ C1] __sys_sendto (net/socket.c:729 net/socket.c:744 net/socket.c:2214) 
[ 529.838942][ C1] ? __pfx___sys_sendto (net/socket.c:2184) 
[ 529.839090][ C1] ? __might_fault (mm/memory.c:6700 mm/memory.c:6693) 
[ 529.839310][ C1] ? trace_lock_acquire (./include/trace/events/lock.h:24 (discriminator 52)) 
[ 529.839452][ C1] ? lock_acquire (kernel/locking/lockdep.c:5798) 
[ 529.839591][ C1] ? __might_fault (mm/memory.c:6700 mm/memory.c:6693) 
[ 529.839728][ C1] ? trace_rseq_update (./include/trace/events/rseq.h:11 (discriminator 52)) 
[ 529.839875][ C1] ? __rseq_handle_notify_resume (kernel/rseq.c:316) 
[ 529.840137][ C1] ? __pfx___rseq_handle_notify_resume (kernel/rseq.c:316) 
[ 529.840328][ C1] ? __local_bh_enable (kernel/softirq.c:343) 
[ 529.840476][ C1] __x64_sys_sendto (net/socket.c:2222) 
[ 529.840702][ C1] ? lockdep_hardirqs_on_prepare (kernel/locking/lockdep.c:4347 kernel/locking/lockdep.c:4406) 
[ 529.840888][ C1] do_syscall_64 (arch/x86/entry/common.c:52 arch/x86/entry/common.c:83) 
[ 529.841037][ C1] entry_SYSCALL_64_after_hwframe (arch/x86/entry/entry_64.S:130) 
[  529.841208][    C1] RIP: 0033:0x7f3e5b80385a
[ 529.841444][ C1] Code: d8 64 89 02 48 c7 c0 ff ff ff ff eb b8 0f 1f 00 f3 0f 1e fa 41 89 ca 64 8b 04 25 18 00 00 00 85 c0 75 15 b8 2c 00 00 00 0f 05 <48> 3d 00 f0 ff ff 77 7e c3 0f 1f 44 00 00 41 54 48 83 ec 30 44 89
All code
========
   0:	d8 64 89 02          	fsubs  0x2(%rcx,%rcx,4)
   4:	48 c7 c0 ff ff ff ff 	mov    $0xffffffffffffffff,%rax
   b:	eb b8                	jmp    0xffffffffffffffc5
   d:	0f 1f 00             	nopl   (%rax)
  10:	f3 0f 1e fa          	endbr64
  14:	41 89 ca             	mov    %ecx,%r10d
  17:	64 8b 04 25 18 00 00 	mov    %fs:0x18,%eax
  1e:	00 
  1f:	85 c0                	test   %eax,%eax
  21:	75 15                	jne    0x38
  23:	b8 2c 00 00 00       	mov    $0x2c,%eax
  28:	0f 05                	syscall
  2a:*	48 3d 00 f0 ff ff    	cmp    $0xfffffffffffff000,%rax		<-- trapping instruction
  30:	77 7e                	ja     0xb0
  32:	c3                   	ret
  33:	0f 1f 44 00 00       	nopl   0x0(%rax,%rax,1)
  38:	41 54                	push   %r12
  3a:	48 83 ec 30          	sub    $0x30,%rsp
  3e:	44                   	rex.R
  3f:	89                   	.byte 0x89

Code starting with the faulting instruction
===========================================
   0:	48 3d 00 f0 ff ff    	cmp    $0xfffffffffffff000,%rax
   6:	77 7e                	ja     0x86
   8:	c3                   	ret
   9:	0f 1f 44 00 00       	nopl   0x0(%rax,%rax,1)
   e:	41 54                	push   %r12
  10:	48 83 ec 30          	sub    $0x30,%rsp
  14:	44                   	rex.R
  15:	89                   	.byte 0x89
[  529.841928][    C1] RSP: 002b:00007ffec99c8998 EFLAGS: 00000246 ORIG_RAX: 000000000000002c
[  529.842224][    C1] RAX: ffffffffffffffda RBX: 00000000376929d0 RCX: 00007f3e5b80385a
[  529.842439][    C1] RDX: 000000000000005c RSI: 00000000376925c0 RDI: 0000000000000005
[  529.842655][    C1] RBP: 00000000376929d0 R08: 00007ffec99c89a0 R09: 0000000000000010
[  529.842942][    C1] R10: 0000000000000000 R11: 0000000000000246 R12: 000000000000005c


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