======================================
| [   31.048207][  T240] 1 lock held by unsigned-md5_ip/240:
| [ 31.048395][ T240] #0: ffff888006c0aa58 (sk_lock-AF_INET){+.+.}-{0:0}, at: do_tcp_getsockopt (net/ipv4/tcp.c:4631) 
| [   31.048748][  T240]
| [   31.048748][  T240] stack backtrace:
[   31.049308][  T240] Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS rel-1.16.3-0-ga6ed6b701f0a-prebuilt.qemu.org 04/01/2014
[   31.049727][  T240] Call Trace:
[   31.049873][  T240]  <TASK>
[ 31.049982][ T240] dump_stack_lvl (lib/dump_stack.c:123) 
[ 31.050179][ T240] lockdep_rcu_suspicious (kernel/locking/lockdep.c:6822) 
[ 31.050387][ T240] tcp_ao_copy_mkts_to_user (net/ipv4/tcp_ao.c:2232 (discriminator 7)) 
[ 31.050580][ T240] ? mark_held_locks (kernel/locking/lockdep.c:4321) 
[ 31.050811][ T240] ? __pfx_tcp_ao_copy_mkts_to_user (net/ipv4/tcp_ao.c:2106) 
[ 31.051039][ T240] ? stack_depot_save_flags (lib/stackdepot.c:664) 
[ 31.051270][ T240] ? kasan_save_stack (mm/kasan/common.c:48) 
[ 31.051449][ T240] ? kasan_save_track (./arch/x86/include/asm/current.h:49 mm/kasan/common.c:60 mm/kasan/common.c:69) 
[ 31.051631][ T240] ? kasan_save_free_info (mm/kasan/generic.c:582) 
[ 31.051821][ T240] ? __kasan_slab_free (mm/kasan/common.c:271) 
[ 31.052007][ T240] ? kfree (mm/slub.c:4579 mm/slub.c:4727) 
[ 31.052147][ T240] ? tcp_ao_parse_crypto (./include/net/tcp_ao.h:67 net/ipv4/tcp_ao.c:1436) 
[ 31.052352][ T240] ? __lock_acquire (kernel/locking/lockdep.c:5202) 
[ 31.052546][ T240] ? lock_acquire.part.0 (kernel/locking/lockdep.c:467 kernel/locking/lockdep.c:5827) 
[ 31.052724][ T240] ? find_held_lock (kernel/locking/lockdep.c:5315) 
[ 31.052907][ T240] ? __lock_release (kernel/locking/lockdep.c:5501) 
[ 31.053078][ T240] ? do_tcp_getsockopt (net/ipv4/tcp.c:4631) 
[ 31.053268][ T240] ? 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) 
[ 31.053461][ T240] ? mark_lock (kernel/locking/lockdep.c:4703 (discriminator 3)) 
[ 31.053611][ T240] ? do_tcp_getsockopt (net/ipv4/tcp.c:4631) 
[ 31.053806][ T240] do_tcp_getsockopt (net/ipv4/tcp.c:4631) 
[ 31.054014][ T240] ? __pfx_do_tcp_getsockopt (net/ipv4/tcp.c:4300) 
[ 31.054211][ T240] ? tcp_ao_add_cmd (net/ipv4/tcp_ao.c:1737) 
[ 31.054408][ T240] ? release_sock (net/core/sock.c:3630) 
[ 31.054586][ T240] ? reacquire_held_locks (kernel/locking/lockdep.c:5350) 
[ 31.054776][ T240] ? release_sock (net/core/sock.c:3630) 
[ 31.054959][ T240] ? rcu_read_lock_any_held (kernel/rcu/update.c:386 kernel/rcu/update.c:380) 
[ 31.055161][ T240] ? validate_chain (kernel/locking/lockdep.c:3797 kernel/locking/lockdep.c:3817 kernel/locking/lockdep.c:3872) 
[ 31.055342][ T240] ? find_held_lock (kernel/locking/lockdep.c:5315) 
[ 31.055535][ T240] ? __pfx_validate_chain (kernel/locking/lockdep.c:3860) 
[ 31.055715][ T240] ? __pfx_validate_chain (kernel/locking/lockdep.c:3860) 
[ 31.055892][ T240] ? 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) 
[ 31.056081][ T240] ? mark_lock (kernel/locking/lockdep.c:4703 (discriminator 3)) 
[ 31.056218][ T240] ? __lock_acquire (kernel/locking/lockdep.c:5202) 
[ 31.056404][ T240] ? find_held_lock (kernel/locking/lockdep.c:5315) 
[ 31.056581][ T240] ? __lock_release (kernel/locking/lockdep.c:5501) 
[ 31.056760][ T240] ? __might_fault (mm/memory.c:6705 mm/memory.c:6698) 
[ 31.056946][ T240] ? __pfx___lock_release (kernel/locking/lockdep.c:5477) 
[ 31.057131][ T240] ? trace_lock_acquire (./include/trace/events/lock.h:24 (discriminator 52)) 
[ 31.057324][ T240] ? find_held_lock (kernel/locking/lockdep.c:5315) 
[ 31.057504][ T240] ? __might_fault (mm/memory.c:6705 mm/memory.c:6698) 
[ 31.057696][ T240] ? __might_fault (mm/memory.c:6705 mm/memory.c:6698) 
[ 31.057879][ T240] tcp_getsockopt (net/ipv4/tcp.c:4673 net/ipv4/tcp.c:4664) 
[ 31.058075][ T240] do_sock_getsockopt (net/socket.c:2396) 
[ 31.058257][ T240] ? __fget_files (./include/linux/rcupdate.h:347 ./include/linux/rcupdate.h:880 fs/file.c:1006) 
[ 31.058439][ T240] ? __pfx_do_sock_getsockopt (net/socket.c:2374) 
[ 31.058637][ T240] ? fdget (fs/file.c:1121 fs/file.c:1128) 
[ 31.058776][ T240] __sys_getsockopt (./include/linux/file.h:35 net/socket.c:2428) 
[ 31.058964][ T240] ? __pfx___sys_getsockopt (net/socket.c:2415) 
[ 31.059184][ T240] ? __pfx_task_work_run (kernel/task_work.c:207) 
[ 31.059378][ T240] ? do_user_addr_fault (./include/linux/rcupdate.h:882 ./include/linux/mm.h:729 arch/x86/mm/fault.c:1340) 
[ 31.059568][ T240] __x64_sys_getsockopt (net/socket.c:2432) 
[ 31.059749][ T240] ? lockdep_hardirqs_on_prepare (kernel/locking/lockdep.c:4347 kernel/locking/lockdep.c:4406) 
[ 31.059984][ T240] do_syscall_64 (arch/x86/entry/common.c:52 arch/x86/entry/common.c:83) 
[ 31.060170][ T240] entry_SYSCALL_64_after_hwframe (arch/x86/entry/entry_64.S:130) 
[   31.060401][  T240] RIP: 0033:0x7fa58a91546e
[ 31.060590][ T240] 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
[   31.061217][  T240] RSP: 002b:00007fa589fc0938 EFLAGS: 00000246 ORIG_RAX: 0000000000000037
[   31.061509][  T240] RAX: ffffffffffffffda RBX: 00007fa589fc0c00 RCX: 00007fa58a91546e
[   31.061780][  T240] RDX: 0000000000000029 RSI: 0000000000000006 RDI: 000000000000000a
[   31.062036][  T240] RBP: 00007fa589fc0950 R08: 00007fa589fc094c R09: 0000000000000064
[   31.062288][  T240] R10: 00007fa589fc0950 R11: 0000000000000246 R12: 000000000000000a
[   31.062558][  T240] R13: 0000000000000064 R14: 0000000000000000 R15: 0000000000000064
| [   31.065696][  T240] 1 lock held by unsigned-md5_ip/240:
| [ 31.065851][ T240] #0: ffff888006c0aa58 (sk_lock-AF_INET){+.+.}-{0:0}, at: inet_stream_connect (net/ipv4/af_inet.c:748) 
| [   31.066144][  T240]
| [   31.066144][  T240] stack backtrace:
[   31.066631][  T240] Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS rel-1.16.3-0-ga6ed6b701f0a-prebuilt.qemu.org 04/01/2014
[   31.066985][  T240] Call Trace:
[   31.067110][  T240]  <TASK>
[ 31.067247][ T240] dump_stack_lvl (lib/dump_stack.c:123) 
[ 31.067403][ T240] lockdep_rcu_suspicious (kernel/locking/lockdep.c:6822) 
[ 31.067572][ T240] __tcp_ao_do_lookup.part.0 (net/ipv4/tcp_ao.c:208) 
[ 31.067737][ T240] tcp_v4_ao_lookup (net/ipv4/tcp_ao.c:200 net/ipv4/tcp_ao.c:222 net/ipv4/tcp_ao.c:720) 
[ 31.067967][ T240] tcp_connect (net/ipv4/tcp_output.c:4114) 
[ 31.068147][ T240] tcp_v4_connect (net/ipv4/tcp_ipv4.c:342) 
[ 31.068327][ T240] ? __pfx_tcp_v4_connect (net/ipv4/tcp_ipv4.c:220) 
[ 31.068484][ T240] ? mark_lock (kernel/locking/lockdep.c:4703 (discriminator 3)) 
[ 31.068616][ T240] __inet_stream_connect (net/ipv4/af_inet.c:677) 
[ 31.068770][ T240] ? lockdep_hardirqs_on_prepare (kernel/locking/lockdep.c:4347 kernel/locking/lockdep.c:4406) 
[ 31.068971][ T240] inet_stream_connect (net/ipv4/af_inet.c:749) 
[ 31.069132][ T240] __sys_connect (net/socket.c:2071 net/socket.c:2088) 
[ 31.069286][ T240] ? __pfx___sys_connect (net/socket.c:2078) 
[ 31.069442][ T240] ? do_fcntl (fs/fcntl.c:473) 
[ 31.069563][ T240] ? __pfx_do_fcntl (fs/fcntl.c:443) 
[ 31.069722][ T240] ? __fget_files (fs/file.c:1009) 
[ 31.069899][ T240] __x64_sys_connect (net/socket.c:2095) 
[ 31.070064][ T240] do_syscall_64 (arch/x86/entry/common.c:52 arch/x86/entry/common.c:83) 
[ 31.070218][ T240] entry_SYSCALL_64_after_hwframe (arch/x86/entry/entry_64.S:130) 
[   31.070411][  T240] RIP: 0033:0x7fa58a91540b
[ 31.070613][ T240] 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
[   31.071139][  T240] RSP: 002b:00007fa589fc0d30 EFLAGS: 00000293 ORIG_RAX: 000000000000002a
[   31.071405][  T240] RAX: ffffffffffffffda RBX: 0000000000000010 RCX: 00007fa58a91540b
[   31.071640][  T240] RDX: 0000000000000010 RSI: 00007fa589fc0d90 RDI: 000000000000000a
[   31.071869][  T240] RBP: 000000000000000a R08: 0000000000000000 R09: 0000000000419480
[   31.072104][  T240] R10: 00007fa58a7cd598 R11: 0000000000000293 R12: 0000000000412df0
[   31.072339][  T240] R13: 0000000000000005 R14: 00007fa589fc0d90 R15: 0000000000000000
| [   31.079149][  T240] 1 lock held by unsigned-md5_ip/240:
| [ 31.079332][ T240] #0: ffff888006c0aa58 (sk_lock-AF_INET){+.+.}-{0:0}, at: inet_stream_connect (net/ipv4/af_inet.c:748) 
| [   31.079653][  T240]
| [   31.079653][  T240] stack backtrace:
[   31.080165][  T240] Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS rel-1.16.3-0-ga6ed6b701f0a-prebuilt.qemu.org 04/01/2014
[   31.080540][  T240] Call Trace:
[   31.080661][  T240]  <TASK>
[ 31.080753][ T240] dump_stack_lvl (lib/dump_stack.c:123) 
[ 31.080955][ T240] lockdep_rcu_suspicious (kernel/locking/lockdep.c:6822) 
[ 31.081125][ T240] tcp_ao_finish_connect (net/ipv4/tcp_ao.c:1183 (discriminator 7)) 
[ 31.081305][ T240] tcp_finish_connect (net/ipv4/tcp_input.c:6340) 
[ 31.081524][ T240] tcp_rcv_synsent_state_process (net/ipv4/tcp_input.c:6576) 
[ 31.081732][ T240] ? 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) 
[ 31.081907][ T240] ? mark_lock (kernel/locking/lockdep.c:4703 (discriminator 3)) 
[ 31.082038][ T240] ? __pfx_tcp_rcv_synsent_state_process (net/ipv4/tcp_input.c:6455) 
[ 31.082257][ T240] ? lockdep_hardirqs_on_prepare (kernel/locking/lockdep.c:4347 kernel/locking/lockdep.c:4406) 
[ 31.082501][ T240] ? kvm_clock_get_cycles (./arch/x86/include/asm/preempt.h:94 arch/x86/kernel/kvmclock.c:80 arch/x86/kernel/kvmclock.c:86) 
[ 31.082664][ T240] ? 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)) 
[ 31.082784][ T240] ? __lock_acquire (kernel/locking/lockdep.c:5202) 
[ 31.082954][ T240] tcp_rcv_state_process (net/ipv4/tcp_input.c:6796) 
[ 31.083113][ T240] ? __lock_release (kernel/locking/lockdep.c:5501) 
[ 31.083267][ T240] ? __release_sock (./include/net/sock.h:1121 net/core/sock.c:3077) 
[ 31.083441][ T240] ? __pfx_tcp_rcv_state_process (net/ipv4/tcp_input.c:6751) 
[ 31.083636][ T240] ? mark_lock (kernel/locking/lockdep.c:4703 (discriminator 3)) 
[ 31.083760][ T240] tcp_v4_do_rcv (net/ipv4/tcp_ipv4.c:1945) 
[ 31.084059][ T240] __release_sock (./include/net/sock.h:1121 net/core/sock.c:3077) 
[ 31.084244][ T240] release_sock (net/core/sock.c:3633) 
[ 31.084429][ T240] inet_stream_connect (net/ipv4/af_inet.c:751) 
[ 31.084615][ T240] __sys_connect (net/socket.c:2071 net/socket.c:2088) 
[ 31.084785][ T240] ? __pfx___sys_connect (net/socket.c:2078) 
[ 31.084951][ T240] ? do_fcntl (fs/fcntl.c:473) 
[ 31.085148][ T240] ? __pfx_do_fcntl (fs/fcntl.c:443) 
[ 31.085416][ T240] ? __fget_files (fs/file.c:1009) 
[ 31.085706][ T240] __x64_sys_connect (net/socket.c:2095) 
[ 31.085968][ T240] do_syscall_64 (arch/x86/entry/common.c:52 arch/x86/entry/common.c:83) 
[ 31.086181][ T240] entry_SYSCALL_64_after_hwframe (arch/x86/entry/entry_64.S:130) 
[   31.086382][  T240] RIP: 0033:0x7fa58a91540b
[ 31.086558][ T240] 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
[   31.087138][  T240] RSP: 002b:00007fa589fc0d30 EFLAGS: 00000293 ORIG_RAX: 000000000000002a
[   31.087376][  T240] RAX: ffffffffffffffda RBX: 0000000000000010 RCX: 00007fa58a91540b
[   31.087632][  T240] RDX: 0000000000000010 RSI: 00007fa589fc0d90 RDI: 000000000000000a
[   31.087882][  T240] RBP: 000000000000000a R08: 0000000000000000 R09: 0000000000419480
[   31.088158][  T240] R10: 00007fa58a7cd598 R11: 0000000000000293 R12: 0000000000412df0


Finger prints:
lockdep_rcu_suspicious:tcp_v4_ao_lookup:tcp_connect:tcp_v4_connect:__inet_stream_connect
lockdep_rcu_suspicious:tcp_ao_copy_mkts_to_user:do_tcp_getsockopt:tcp_getsockopt:do_sock_getsockopt
lockdep_rcu_suspicious:tcp_ao_finish_connect:tcp_finish_connect:tcp_rcv_synsent_state_process:tcp_rcv_state_process