======================================
| [   27.315857][  T241] 1 lock held by connect_ipv6/241:
| [ 27.316025][ T241] #0: ffff888005791098 (sk_lock-AF_INET6){+.+.}-{0:0}, at: do_tcp_getsockopt (net/ipv4/tcp.c:4631) 
| [   27.316367][  T241]
| [   27.316367][  T241] stack backtrace:
[   27.316912][  T241] Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS rel-1.16.3-0-ga6ed6b701f0a-prebuilt.qemu.org 04/01/2014
[   27.317278][  T241] Call Trace:
[   27.317404][  T241]  <TASK>
[ 27.317496][ T241] dump_stack_lvl (lib/dump_stack.c:123) 
[ 27.317675][ T241] lockdep_rcu_suspicious (kernel/locking/lockdep.c:6822) 
[ 27.317862][ T241] tcp_ao_copy_mkts_to_user (net/ipv4/tcp_ao.c:2232 (discriminator 7)) 
[ 27.318049][ T241] ? mark_held_locks (kernel/locking/lockdep.c:4321) 
[ 27.318230][ T241] ? __pfx_tcp_ao_copy_mkts_to_user (net/ipv4/tcp_ao.c:2106) 
[ 27.318428][ T241] ? stack_depot_save_flags (lib/stackdepot.c:664) 
[ 27.318620][ T241] ? kasan_save_stack (mm/kasan/common.c:48) 
[ 27.318795][ T241] ? kasan_save_track (./arch/x86/include/asm/current.h:49 mm/kasan/common.c:60 mm/kasan/common.c:69) 
[ 27.318980][ T241] ? kfree (mm/slub.c:4579 mm/slub.c:4727) 
[ 27.319100][ T241] ? tcp_ao_parse_crypto (./include/net/tcp_ao.h:67 net/ipv4/tcp_ao.c:1436) 
[ 27.319308][ T241] ? __lock_acquire (kernel/locking/lockdep.c:5202) 
[ 27.319478][ T241] ? lock_acquire.part.0 (kernel/locking/lockdep.c:467 kernel/locking/lockdep.c:5827) 
[ 27.319652][ T241] ? find_held_lock (kernel/locking/lockdep.c:5315) 
[ 27.319894][ T241] ? __lock_release (kernel/locking/lockdep.c:5501) 
[ 27.320066][ T241] ? do_tcp_getsockopt (net/ipv4/tcp.c:4631) 
[ 27.320228][ T241] ? 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) 
[ 27.320408][ T241] ? mark_lock (kernel/locking/lockdep.c:4703 (discriminator 3)) 
[ 27.320537][ T241] ? do_tcp_getsockopt (net/ipv4/tcp.c:4631) 
[ 27.320713][ T241] do_tcp_getsockopt (net/ipv4/tcp.c:4631) 
[ 27.320923][ T241] ? __pfx_do_tcp_getsockopt (net/ipv4/tcp.c:4300) 
[ 27.321102][ T241] ? tcp_ao_add_cmd (net/ipv4/tcp_ao.c:1737) 
[ 27.321301][ T241] ? release_sock (net/core/sock.c:3630) 
[ 27.321465][ T241] ? reacquire_held_locks (kernel/locking/lockdep.c:5350) 
[ 27.321629][ T241] ? release_sock (net/core/sock.c:3630) 
[ 27.321819][ T241] ? rcu_read_lock_any_held (kernel/rcu/update.c:386 kernel/rcu/update.c:380) 
[ 27.321974][ T241] ? validate_chain (kernel/locking/lockdep.c:3797 kernel/locking/lockdep.c:3817 kernel/locking/lockdep.c:3872) 
[ 27.322149][ T241] ? find_held_lock (kernel/locking/lockdep.c:5315) 
[ 27.322307][ T241] ? __lock_release (kernel/locking/lockdep.c:5501) 
[ 27.322479][ T241] ? __pfx_validate_chain (kernel/locking/lockdep.c:3860) 
[ 27.322639][ T241] ? 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) 
[ 27.322824][ T241] ? mark_lock (kernel/locking/lockdep.c:4703 (discriminator 3)) 
[ 27.322948][ T241] ? __lock_acquire (kernel/locking/lockdep.c:5202) 
[ 27.323131][ T241] ? find_held_lock (kernel/locking/lockdep.c:5315) 
[ 27.323293][ T241] ? __lock_release (kernel/locking/lockdep.c:5501) 
[ 27.323459][ T241] ? __might_fault (mm/memory.c:6705 mm/memory.c:6698) 
[ 27.323615][ T241] ? __pfx___lock_release (kernel/locking/lockdep.c:5477) 
[ 27.323807][ T241] ? trace_lock_acquire (./include/trace/events/lock.h:24 (discriminator 52)) 
[ 27.323971][ T241] ? find_held_lock (kernel/locking/lockdep.c:5315) 
[ 27.324156][ T241] ? __might_fault (mm/memory.c:6705 mm/memory.c:6698) 
[ 27.324310][ T241] ? __might_fault (mm/memory.c:6705 mm/memory.c:6698) 
[ 27.324488][ T241] tcp_getsockopt (net/ipv4/tcp.c:4673 net/ipv4/tcp.c:4664) 
[ 27.324653][ T241] do_sock_getsockopt (net/socket.c:2396) 
[ 27.324854][ T241] ? __fget_files (./include/linux/rcupdate.h:347 ./include/linux/rcupdate.h:880 fs/file.c:1006) 
[ 27.325020][ T241] ? __pfx_do_sock_getsockopt (net/socket.c:2374) 
[ 27.325195][ T241] ? fdget (fs/file.c:1121 fs/file.c:1128) 
[ 27.325319][ T241] __sys_getsockopt (./include/linux/file.h:35 net/socket.c:2428) 
[ 27.325477][ T241] ? __sys_setsockopt (net/socket.c:2360) 
[ 27.325638][ T241] ? __pfx___sys_getsockopt (net/socket.c:2415) 
[ 27.325838][ T241] ? do_user_addr_fault (./include/linux/rcupdate.h:882 ./include/linux/mm.h:729 arch/x86/mm/fault.c:1340) 
[ 27.326003][ T241] __x64_sys_getsockopt (net/socket.c:2432) 
[ 27.326177][ T241] ? lockdep_hardirqs_on_prepare (kernel/locking/lockdep.c:4347 kernel/locking/lockdep.c:4406) 
[ 27.326373][ T241] do_syscall_64 (arch/x86/entry/common.c:52 arch/x86/entry/common.c:83) 
[ 27.326552][ T241] entry_SYSCALL_64_after_hwframe (arch/x86/entry/entry_64.S:130) 
[   27.326760][  T241] RIP: 0033:0x7f2f8100446e
[ 27.326950][ T241] Code: 1f 44 00 00 48 8b 15 91 99 0a 00 f7 d8 64 89 02 b8 ff ff ff ff eb b8 0f 1f 44 00 00 f3 0f 1e fa 49 89 ca b8 37 00 00 00 0f 05 <48> 3d 00 f0 ff ff 77 0a c3 66 0f 1f 84 00 00 00 00 00 48 8b 15 59
All code
========
   0:	1f                   	(bad)
   1:	44 00 00             	add    %r8b,(%rax)
   4:	48 8b 15 91 99 0a 00 	mov    0xa9991(%rip),%rdx        # 0xa999c
   b:	f7 d8                	neg    %eax
   d:	64 89 02             	mov    %eax,%fs:(%rdx)
  10:	b8 ff ff ff ff       	mov    $0xffffffff,%eax
  15:	eb b8                	jmp    0xffffffffffffffcf
  17:	0f 1f 44 00 00       	nopl   0x0(%rax,%rax,1)
  1c:	f3 0f 1e fa          	endbr64
  20:	49 89 ca             	mov    %rcx,%r10
  23:	b8 37 00 00 00       	mov    $0x37,%eax
  28:	0f 05                	syscall
  2a:*	48 3d 00 f0 ff ff    	cmp    $0xfffffffffffff000,%rax		<-- trapping instruction
  30:	77 0a                	ja     0x3c
  32:	c3                   	ret
  33:	66 0f 1f 84 00 00 00 	nopw   0x0(%rax,%rax,1)
  3a:	00 00 
  3c:	48                   	rex.W
  3d:	8b                   	.byte 0x8b
  3e:	15                   	.byte 0x15
  3f:	59                   	pop    %rcx

Code starting with the faulting instruction
===========================================
   0:	48 3d 00 f0 ff ff    	cmp    $0xfffffffffffff000,%rax
   6:	77 0a                	ja     0x12
   8:	c3                   	ret
   9:	66 0f 1f 84 00 00 00 	nopw   0x0(%rax,%rax,1)
  10:	00 00 
  12:	48                   	rex.W
  13:	8b                   	.byte 0x8b
  14:	15                   	.byte 0x15
  15:	59                   	pop    %rcx
[   27.327544][  T241] RSP: 002b:00007f2f7bffea28 EFLAGS: 00000246 ORIG_RAX: 0000000000000037
[   27.327826][  T241] RAX: ffffffffffffffda RBX: 00007f2f7bffece0 RCX: 00007f2f8100446e
[   27.328067][  T241] RDX: 0000000000000029 RSI: 0000000000000006 RDI: 000000000000000a
[   27.328329][  T241] RBP: 00007f2f7bffea40 R08: 00007f2f7bffea3c R09: 0000000000000064
[   27.328573][  T241] R10: 00007f2f7bffea40 R11: 0000000000000246 R12: 000000000000000a
[   27.328854][  T241] R13: 0000000000000064 R14: 0000000000000080 R15: 0000000000000064
| [   27.333120][  T241] 1 lock held by connect_ipv6/241:
| [ 27.333280][ T241] #0: ffff888005791098 (sk_lock-AF_INET6){+.+.}-{0:0}, at: inet_stream_connect (net/ipv4/af_inet.c:748) 
| [   27.333577][  T241]
| [   27.333577][  T241] stack backtrace:
[   27.334066][  T241] Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS rel-1.16.3-0-ga6ed6b701f0a-prebuilt.qemu.org 04/01/2014
[   27.334418][  T241] Call Trace:
[   27.334544][  T241]  <TASK>
[ 27.334630][ T241] dump_stack_lvl (lib/dump_stack.c:123) 
[ 27.334828][ T241] lockdep_rcu_suspicious (kernel/locking/lockdep.c:6822) 
[ 27.334995][ T241] __tcp_ao_do_lookup.part.0 (net/ipv4/tcp_ao.c:208) 
[ 27.335171][ T241] tcp_ao_do_lookup (net/ipv4/tcp_ao.c:200 net/ipv4/tcp_ao.c:222) 
[ 27.335329][ T241] tcp_connect (net/ipv4/tcp_output.c:4114) 
[ 27.335514][ T241] ? rt6_get_cookie (./include/linux/rcupdate.h:347 ./include/linux/rcupdate.h:880 ./include/net/ip6_fib.h:312) 
[ 27.335681][ T241] tcp_v6_connect (net/ipv6/tcp_ipv6.c:333) 
[ 27.335894][ T241] ? __pfx_tcp_v6_connect (net/ipv6/tcp_ipv6.c:137) 
[ 27.336050][ T241] ? lock_acquire.part.0 (kernel/locking/lockdep.c:467 kernel/locking/lockdep.c:5827) 
[ 27.336204][ T241] ? find_held_lock (kernel/locking/lockdep.c:5315) 
[ 27.336381][ T241] ? 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) 
[ 27.336541][ T241] ? mark_lock (kernel/locking/lockdep.c:4703 (discriminator 3)) 
[ 27.336660][ T241] __inet_stream_connect (net/ipv4/af_inet.c:677) 
[ 27.336834][ T241] ? lockdep_hardirqs_on_prepare (kernel/locking/lockdep.c:4347 kernel/locking/lockdep.c:4406) 
[ 27.337018][ T241] inet_stream_connect (net/ipv4/af_inet.c:749) 
[ 27.337171][ T241] __sys_connect (net/socket.c:2071 net/socket.c:2088) 
[ 27.337325][ T241] ? __pfx___sys_connect (net/socket.c:2078) 
[ 27.337470][ T241] ? do_fcntl (fs/fcntl.c:473) 
[ 27.337608][ T241] ? __fget_files (fs/file.c:1009) 
[ 27.337789][ T241] __x64_sys_connect (net/socket.c:2095) 
[ 27.337940][ T241] do_syscall_64 (arch/x86/entry/common.c:52 arch/x86/entry/common.c:83) 
[ 27.338107][ T241] entry_SYSCALL_64_after_hwframe (arch/x86/entry/entry_64.S:130) 
[   27.338293][  T241] RIP: 0033:0x7f2f8100440b
[ 27.338470][ T241] Code: 83 ec 18 89 54 24 0c 48 89 34 24 89 7c 24 08 e8 eb c7 f4 ff 8b 54 24 0c 48 8b 34 24 41 89 c0 8b 7c 24 08 b8 2a 00 00 00 0f 05 <48> 3d 00 f0 ff ff 77 35 44 89 c7 89 44 24 08 e8 41 c8 f4 ff 8b 44
All code
========
   0:	83 ec 18             	sub    $0x18,%esp
   3:	89 54 24 0c          	mov    %edx,0xc(%rsp)
   7:	48 89 34 24          	mov    %rsi,(%rsp)
   b:	89 7c 24 08          	mov    %edi,0x8(%rsp)
   f:	e8 eb c7 f4 ff       	call   0xfffffffffff4c7ff
  14:	8b 54 24 0c          	mov    0xc(%rsp),%edx
  18:	48 8b 34 24          	mov    (%rsp),%rsi
  1c:	41 89 c0             	mov    %eax,%r8d
  1f:	8b 7c 24 08          	mov    0x8(%rsp),%edi
  23:	b8 2a 00 00 00       	mov    $0x2a,%eax
  28:	0f 05                	syscall
  2a:*	48 3d 00 f0 ff ff    	cmp    $0xfffffffffffff000,%rax		<-- trapping instruction
  30:	77 35                	ja     0x67
  32:	44 89 c7             	mov    %r8d,%edi
  35:	89 44 24 08          	mov    %eax,0x8(%rsp)
  39:	e8 41 c8 f4 ff       	call   0xfffffffffff4c87f
  3e:	8b                   	.byte 0x8b
  3f:	44                   	rex.R

Code starting with the faulting instruction
===========================================
   0:	48 3d 00 f0 ff ff    	cmp    $0xfffffffffffff000,%rax
   6:	77 35                	ja     0x3d
   8:	44 89 c7             	mov    %r8d,%edi
   b:	89 44 24 08          	mov    %eax,0x8(%rsp)
   f:	e8 41 c8 f4 ff       	call   0xfffffffffff4c855
  14:	8b                   	.byte 0x8b
  15:	44                   	rex.R
[   27.339015][  T241] RSP: 002b:00007f2f7bffeb70 EFLAGS: 00000293 ORIG_RAX: 000000000000002a
[   27.339254][  T241] RAX: ffffffffffffffda RBX: 000000000000001c RCX: 00007f2f8100440b
[   27.339496][  T241] RDX: 000000000000001c RSI: 00007f2f7bffece0 RDI: 000000000000000a
[   27.339734][  T241] RBP: 000000000000000a R08: 0000000000000000 R09: 00000000004133c0
[   27.340011][  T241] R10: 00007f2f80ebc598 R11: 0000000000000293 R12: 000000000040cd28
[   27.340244][  T241] R13: 0000000000000005 R14: 00007f2f7bffece0 R15: 0000000000000000
| [   27.346753][  T241] 1 lock held by connect_ipv6/241:
| [ 27.347004][ T241] #0: ffff888005791098 (sk_lock-AF_INET6){+.+.}-{0:0}, at: inet_stream_connect (net/ipv4/af_inet.c:748) 
| [   27.347316][  T241]
| [   27.347316][  T241] stack backtrace:
[   27.347840][  T241] Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS rel-1.16.3-0-ga6ed6b701f0a-prebuilt.qemu.org 04/01/2014
[   27.348197][  T241] Call Trace:
[   27.348326][  T241]  <TASK>
[ 27.348425][ T241] dump_stack_lvl (lib/dump_stack.c:123) 
[ 27.348582][ T241] lockdep_rcu_suspicious (kernel/locking/lockdep.c:6822) 
[ 27.348775][ T241] tcp_ao_finish_connect (net/ipv4/tcp_ao.c:1183 (discriminator 7)) 
[ 27.348979][ T241] tcp_finish_connect (net/ipv4/tcp_input.c:6340) 
[ 27.349139][ T241] tcp_rcv_synsent_state_process (net/ipv4/tcp_input.c:6576) 
[ 27.349326][ T241] ? 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) 
[ 27.349479][ T241] ? mark_lock (kernel/locking/lockdep.c:4703 (discriminator 3)) 
[ 27.349597][ T241] ? __pfx_tcp_rcv_synsent_state_process (net/ipv4/tcp_input.c:6455) 
[ 27.349807][ T241] ? lockdep_hardirqs_on_prepare (kernel/locking/lockdep.c:4347 kernel/locking/lockdep.c:4406) 
[ 27.349992][ T241] ? kvm_clock_get_cycles (./arch/x86/include/asm/preempt.h:94 arch/x86/kernel/kvmclock.c:80 arch/x86/kernel/kvmclock.c:86) 
[ 27.350145][ T241] ? ktime_get (kernel/time/timekeeping.c:195 (discriminator 4) kernel/time/timekeeping.c:395 (discriminator 4) kernel/time/timekeeping.c:403 (discriminator 4) kernel/time/timekeeping.c:850 (discriminator 4)) 
[ 27.350269][ T241] tcp_rcv_state_process (net/ipv4/tcp_input.c:6796) 
[ 27.350425][ T241] ? __lock_release (kernel/locking/lockdep.c:5501) 
[ 27.350574][ T241] ? __release_sock (./include/net/sock.h:1121 net/core/sock.c:3077) 
[ 27.350737][ T241] ? __pfx_tcp_rcv_state_process (net/ipv4/tcp_input.c:6751) 
[ 27.350922][ T241] ? 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) 
[ 27.351102][ T241] ? mark_lock (kernel/locking/lockdep.c:4703 (discriminator 3)) 
[ 27.351224][ T241] tcp_v6_do_rcv (net/ipv6/tcp_ipv6.c:1676) 
[ 27.351384][ T241] ? lockdep_hardirqs_on_prepare (kernel/locking/lockdep.c:4347 kernel/locking/lockdep.c:4406) 
[ 27.351580][ T241] __release_sock (net/core/sock.c:3079) 
[ 27.351757][ T241] release_sock (net/core/sock.c:3633) 
[ 27.351920][ T241] inet_stream_connect (net/ipv4/af_inet.c:751) 
[ 27.352074][ T241] __sys_connect (net/socket.c:2071 net/socket.c:2088) 
[ 27.352230][ T241] ? __pfx___sys_connect (net/socket.c:2078) 
[ 27.352381][ T241] ? do_fcntl (fs/fcntl.c:473) 
[ 27.352502][ T241] ? __fget_files (fs/file.c:1009) 
[ 27.352662][ T241] __x64_sys_connect (net/socket.c:2095) 
[ 27.352854][ T241] do_syscall_64 (arch/x86/entry/common.c:52 arch/x86/entry/common.c:83) 
[ 27.353008][ T241] entry_SYSCALL_64_after_hwframe (arch/x86/entry/entry_64.S:130) 
[   27.353198][  T241] RIP: 0033:0x7f2f8100440b
[ 27.353358][ T241] Code: 83 ec 18 89 54 24 0c 48 89 34 24 89 7c 24 08 e8 eb c7 f4 ff 8b 54 24 0c 48 8b 34 24 41 89 c0 8b 7c 24 08 b8 2a 00 00 00 0f 05 <48> 3d 00 f0 ff ff 77 35 44 89 c7 89 44 24 08 e8 41 c8 f4 ff 8b 44
All code
========
   0:	83 ec 18             	sub    $0x18,%esp
   3:	89 54 24 0c          	mov    %edx,0xc(%rsp)
   7:	48 89 34 24          	mov    %rsi,(%rsp)
   b:	89 7c 24 08          	mov    %edi,0x8(%rsp)
   f:	e8 eb c7 f4 ff       	call   0xfffffffffff4c7ff
  14:	8b 54 24 0c          	mov    0xc(%rsp),%edx
  18:	48 8b 34 24          	mov    (%rsp),%rsi
  1c:	41 89 c0             	mov    %eax,%r8d
  1f:	8b 7c 24 08          	mov    0x8(%rsp),%edi
  23:	b8 2a 00 00 00       	mov    $0x2a,%eax
  28:	0f 05                	syscall
  2a:*	48 3d 00 f0 ff ff    	cmp    $0xfffffffffffff000,%rax		<-- trapping instruction
  30:	77 35                	ja     0x67
  32:	44 89 c7             	mov    %r8d,%edi
  35:	89 44 24 08          	mov    %eax,0x8(%rsp)
  39:	e8 41 c8 f4 ff       	call   0xfffffffffff4c87f
  3e:	8b                   	.byte 0x8b
  3f:	44                   	rex.R

Code starting with the faulting instruction
===========================================
   0:	48 3d 00 f0 ff ff    	cmp    $0xfffffffffffff000,%rax
   6:	77 35                	ja     0x3d
   8:	44 89 c7             	mov    %r8d,%edi
   b:	89 44 24 08          	mov    %eax,0x8(%rsp)
   f:	e8 41 c8 f4 ff       	call   0xfffffffffff4c855
  14:	8b                   	.byte 0x8b
  15:	44                   	rex.R
[   27.353887][  T241] RSP: 002b:00007f2f7bffeb70 EFLAGS: 00000293 ORIG_RAX: 000000000000002a
[   27.354114][  T241] RAX: ffffffffffffffda RBX: 000000000000001c RCX: 00007f2f8100440b
[   27.354349][  T241] RDX: 000000000000001c RSI: 00007f2f7bffece0 RDI: 000000000000000a
[   27.354574][  T241] RBP: 000000000000000a R08: 0000000000000000 R09: 00000000004133c0
[   27.354807][  T241] R10: 00007f2f80ebc598 R11: 0000000000000293 R12: 000000000040cd28


Finger prints:
lockdep_rcu_suspicious:tcp_ao_do_lookup:tcp_connect:tcp_v6_connect:__inet_stream_connect
lockdep_rcu_suspicious:tcp_ao_finish_connect:tcp_finish_connect:tcp_rcv_synsent_state_process:tcp_rcv_state_process
lockdep_rcu_suspicious:tcp_ao_copy_mkts_to_user:do_tcp_getsockopt:tcp_getsockopt:do_sock_getsockopt