======================================
| [  114.453164][    C1] page dumped because: VM_BUG_ON_PAGE(page_ref_count(page) == 0)
| [  114.453583][    C1] ------------[ cut here ]------------
| [  114.453859][    C1] kernel BUG at include/linux/mm.h:1140!
| [  114.454163][    C1] Oops: invalid opcode: 0000 [#1] PREEMPT SMP KASAN NOPTI
[  114.454797][    C1] Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS rel-1.16.3-0-ga6ed6b701f0a-prebuilt.qemu.org 04/01/2014
[ 114.455296][ C1] RIP: 0010:__free_pages (./include/linux/mm.h:1140 ./include/linux/mm.h:1138 mm/page_alloc.c:4819) 
[ 114.455537][ C1] Code: 0f 94 c3 e9 ba fe ff ff 48 c7 c6 a0 18 78 a4 4c 89 e7 e8 df bf f4 ff 90 0f 0b 48 c7 c6 40 29 78 a4 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 a4 	mov    $0xffffffffa47818a0,%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 a4 	mov    $0xffffffffa4782940,%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
[  114.456330][    C1] RSP: 0018:ffffc900001e8e08 EFLAGS: 00010246
[  114.456611][    C1] RAX: 000000000000003e RBX: 0000000000000000 RCX: 1ffffffff4a7b43c
[  114.456934][    C1] RDX: 0000000000000000 RSI: 0000000000000004 RDI: 0000000000000001
[  114.457273][    C1] RBP: ffffea000012f674 R08: 0000000000000000 R09: fffffbfff4a7b43c
[  114.457611][    C1] R10: 0000000000000003 R11: 205d314320202020 R12: ffffea000012f640
[  114.457955][    C1] R13: ffffc900001e8ed0 R14: 0000000000000000 R15: 0000000000000004
[  114.458290][    C1] FS:  00007f70996a7740(0000) GS:ffff888036080000(0000) knlGS:0000000000000000
[  114.458690][    C1] CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
[  114.458971][    C1] CR2: 00007fffc6a559e9 CR3: 0000000002b96003 CR4: 0000000000772ef0
[  114.459325][    C1] DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
[  114.459673][    C1] DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400
[  114.460005][    C1] PKRU: 55555554
[  114.460189][    C1] Call Trace:
[  114.460357][    C1]  <IRQ>
[ 114.460473][ C1] ? die (arch/x86/kernel/dumpstack.c:421 arch/x86/kernel/dumpstack.c:434 arch/x86/kernel/dumpstack.c:447) 
[ 114.460635][ C1] ? do_trap (arch/x86/kernel/traps.c:156 arch/x86/kernel/traps.c:197) 
[ 114.460803][ C1] ? __free_pages (./include/linux/mm.h:1140 ./include/linux/mm.h:1138 mm/page_alloc.c:4819) 
[ 114.461029][ C1] ? do_error_trap (./arch/x86/include/asm/traps.h:58 arch/x86/kernel/traps.c:218) 
[ 114.461249][ C1] ? __free_pages (./include/linux/mm.h:1140 ./include/linux/mm.h:1138 mm/page_alloc.c:4819) 
[ 114.461463][ C1] ? __free_pages (./include/linux/mm.h:1140 ./include/linux/mm.h:1138 mm/page_alloc.c:4819) 
[ 114.461693][ C1] ? handle_invalid_op (arch/x86/kernel/traps.c:256) 
[ 114.461913][ C1] ? __free_pages (./include/linux/mm.h:1140 ./include/linux/mm.h:1138 mm/page_alloc.c:4819) 
[ 114.462110][ C1] ? exc_invalid_op (arch/x86/kernel/traps.c:315) 
[ 114.462273][ C1] ? asm_exc_invalid_op (./arch/x86/include/asm/idtentry.h:621) 
[ 114.462449][ C1] ? __free_pages (./include/linux/mm.h:1140 ./include/linux/mm.h:1138 mm/page_alloc.c:4819) 
[ 114.462613][ C1] ? __free_pages (./include/linux/mm.h:1140 ./include/linux/mm.h:1138 mm/page_alloc.c:4819) 
[ 114.462760][ C1] ? rcu_do_batch (kernel/rcu/tree.c:2567) 
[ 114.462913][ C1] neigh_hash_free_rcu (net/core/neighbour.c:554) 
[ 114.463128][ C1] rcu_do_batch (kernel/rcu/tree.c:2567) 
[ 114.463350][ C1] ? __pfx_rcu_do_batch (kernel/rcu/tree.c:2491) 
[ 114.463555][ C1] ? lockdep_hardirqs_on_prepare (kernel/locking/lockdep.c:4339 kernel/locking/lockdep.c:4406) 
[ 114.463864][ C1] rcu_core (kernel/rcu/tree.c:2825) 
[ 114.464028][ C1] handle_softirqs (kernel/softirq.c:554) 
[ 114.464266][ C1] ? __dev_queue_xmit (./include/linux/rcupdate.h:347 ./include/linux/rcupdate.h:917 net/core/dev.c:4457) 
[ 114.464477][ C1] do_softirq (kernel/softirq.c:455 kernel/softirq.c:442) 
[  114.464647][    C1]  </IRQ>
[  114.464770][    C1]  <TASK>
[ 114.464889][ C1] __local_bh_enable_ip (kernel/softirq.c:382) 
[ 114.465120][ C1] ? __dev_queue_xmit (./include/linux/rcupdate.h:347 ./include/linux/rcupdate.h:917 net/core/dev.c:4457) 
[ 114.465281][ C1] __dev_queue_xmit (net/core/dev.c:4458) 
[ 114.465490][ C1] ? __lock_release (kernel/locking/lockdep.c:5501) 
[ 114.465730][ C1] ? ip6_finish_output2 (./include/net/neighbour.h:537 net/ipv6/ip6_output.c:141) 
[ 114.465950][ C1] ? __pfx___lock_release (kernel/locking/lockdep.c:5477) 
[ 114.466185][ C1] ? __pfx_lock_acquire.part.0 (kernel/locking/lockdep.c:5790) 
[ 114.466417][ C1] ? __pfx___dev_queue_xmit (net/core/dev.c:4339) 
[ 114.466654][ C1] ? eth_header (net/ethernet/eth.c:100) 
[ 114.466897][ C1] ? neigh_resolve_output (./include/linux/netdevice.h:3216 net/core/neighbour.c:1524 net/core/neighbour.c:1509) 
[ 114.467137][ C1] ip6_finish_output2 (./include/net/neighbour.h:537 net/ipv6/ip6_output.c:141) 
[ 114.467376][ C1] ip6_finish_output (net/ipv6/ip6_output.c:215 net/ipv6/ip6_output.c:226) 
[ 114.467610][ C1] ? hlock_class (./arch/x86/include/asm/bitops.h:227 ./arch/x86/include/asm/bitops.h:239 ./include/asm-generic/bitops/instrumented-non-atomic.h:142 kernel/locking/lockdep.c:228) 
[ 114.467848][ C1] ip6_output (./include/linux/netfilter.h:303 net/ipv6/ip6_output.c:247) 
[ 114.468041][ C1] ? __pfx_ip6_output (net/ipv6/ip6_output.c:234) 
[ 114.468297][ C1] NF_HOOK.constprop.0 (./include/linux/rcupdate.h:337 ./include/linux/rcupdate.h:849 ./include/linux/netfilter.h:238 ./include/linux/netfilter.h:312) 
[ 114.468534][ C1] ? __pfx_NF_HOOK.constprop.0 (./include/linux/netfilter.h:308) 
[ 114.468777][ C1] ? __pfx_lock_acquire.part.0 (kernel/locking/lockdep.c:5790) 
[ 114.469012][ C1] ? trace_lock_acquire (./include/trace/events/lock.h:24 (discriminator 52)) 
[ 114.469245][ C1] ? rawv6_send_hdrinc (./include/linux/rcupdate.h:337 ./include/linux/rcupdate.h:849 net/ipv6/raw.c:659) 
[ 114.469477][ C1] ? lock_acquire (kernel/locking/lockdep.c:5798) 
[ 114.469711][ C1] ? rawv6_send_hdrinc (./include/linux/rcupdate.h:337 ./include/linux/rcupdate.h:849 net/ipv6/raw.c:659) 
[ 114.469949][ C1] rawv6_send_hdrinc (net/ipv6/raw.c:663 (discriminator 60)) 
[ 114.470184][ C1] ? __pfx_rawv6_send_hdrinc (net/ipv6/raw.c:596) 
[ 114.470423][ C1] ? ip6_dst_hoplimit.part.0.isra.0 (./include/linux/rcupdate.h:347 ./include/linux/rcupdate.h:880 net/ipv6/output_core.c:117) 
[ 114.470725][ C1] rawv6_sendmsg (net/ipv6/raw.c:914) 
[ 114.470966][ C1] ? __pfx_rawv6_sendmsg (net/ipv6/raw.c:741) 
[ 114.471202][ C1] ? __lock_acquire (kernel/locking/lockdep.c:5202) 
[ 114.471426][ C1] ? find_held_lock (kernel/locking/lockdep.c:5315) 
[ 114.471650][ C1] ? __lock_release (kernel/locking/lockdep.c:5501) 
[ 114.471901][ C1] ? __might_fault (mm/memory.c:6700 mm/memory.c:6693) 
[ 114.472131][ C1] ? lock_acquire (kernel/locking/lockdep.c:5798) 
[ 114.472362][ C1] ? __might_fault (mm/memory.c:6700 mm/memory.c:6693) 
[ 114.472590][ C1] ? __might_fault (mm/memory.c:6700 mm/memory.c:6693) 
[ 114.472813][ C1] ? __sys_sendto (net/socket.c:729 net/socket.c:744 net/socket.c:2214) 
[ 114.473053][ C1] __sys_sendto (net/socket.c:729 net/socket.c:744 net/socket.c:2214) 
[ 114.473293][ C1] ? __pfx___sys_sendto (net/socket.c:2184) 
[ 114.473559][ C1] ? __might_fault (mm/memory.c:6700 mm/memory.c:6693) 
[ 114.473841][ C1] ? trace_lock_acquire (./include/trace/events/lock.h:24 (discriminator 52)) 
[ 114.474056][ C1] ? lock_acquire (kernel/locking/lockdep.c:5798) 
[ 114.474320][ C1] ? __might_fault (mm/memory.c:6700 mm/memory.c:6693) 
[ 114.474549][ C1] ? trace_rseq_update (./include/trace/events/rseq.h:11 (discriminator 52)) 
[ 114.474798][ C1] ? __pfx___rseq_handle_notify_resume (kernel/rseq.c:316) 
[ 114.475101][ C1] ? __pfx_task_work_run (kernel/task_work.c:196) 
[ 114.475330][ C1] ? __local_bh_enable (kernel/softirq.c:343) 
[ 114.475567][ C1] __x64_sys_sendto (net/socket.c:2222) 
[ 114.475809][ C1] ? lockdep_hardirqs_on_prepare (kernel/locking/lockdep.c:4347 kernel/locking/lockdep.c:4406) 
[ 114.476089][ C1] do_syscall_64 (arch/x86/entry/common.c:52 arch/x86/entry/common.c:83) 
[ 114.476330][ C1] entry_SYSCALL_64_after_hwframe (arch/x86/entry/entry_64.S:130) 
[  114.476620][    C1] RIP: 0033:0x7f709990185a
[ 114.476860][ 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
[  114.477663][    C1] RSP: 002b:00007fffc6a55468 EFLAGS: 00000246 ORIG_RAX: 000000000000002c
[  114.478029][    C1] RAX: ffffffffffffffda RBX: 0000000038cbfec0 RCX: 00007f709990185a
[  114.478372][    C1] RDX: 0000000000000070 RSI: 0000000038cc0160 RDI: 0000000000000005
[  114.478730][    C1] RBP: 0000000038cbfec0 R08: 00007fffc6a55470 R09: 000000000000001c
[  114.478990][    C1] R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000070


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