======================================
| [ 31.543570][ T428] #0: ffffffff9f207e88 (rtnl_mutex){+.+.}-{4:4}, at: rtnl_dellink (net/core/rtnetlink.c:3512)
| [ 31.543849][ T428] #1: ffffffff9f1f6a70 ((netdev_chain).rwsem){++++}-{4:4}, at: blocking_notifier_call_chain (kernel/notifier.c:380 kernel/notifier.c:368)
| [   31.544165][  T428]
| [   31.544165][  T428] stack backtrace:
[   31.544591][  T428] Hardware name: Bochs Bochs, BIOS Bochs 01/01/2011
[   31.544779][  T428] Call Trace:
[   31.544894][  T428]  <TASK>
[ 31.544982][ T428] dump_stack_lvl (lib/dump_stack.c:123)
[ 31.545141][ T428] print_deadlock_bug (kernel/locking/lockdep.c:3040)
[ 31.545322][ T428] validate_chain (kernel/locking/lockdep.c:3894)
[ 31.545471][ T428] ? __lock_acquire (kernel/locking/lockdep.c:5226)
[ 31.545645][ T428] ? __pfx_validate_chain (kernel/locking/lockdep.c:3860)
[ 31.545803][ T428] ? 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)
[ 31.545954][ T428] ? mark_lock (kernel/locking/lockdep.c:4727 (discriminator 3))
[ 31.546069][ T428] __lock_acquire (kernel/locking/lockdep.c:5226)
[ 31.546223][ T428] lock_acquire.part.0 (kernel/locking/lockdep.c:467 kernel/locking/lockdep.c:5851)
[ 31.546394][ T428] ? blocking_notifier_call_chain (kernel/notifier.c:380 kernel/notifier.c:368)
[ 31.546591][ T428] ? __pfx_lock_acquire.part.0 (kernel/locking/lockdep.c:5814)
[ 31.546750][ T428] ? trace_lock_acquire (./include/trace/events/lock.h:24 (discriminator 37))
[ 31.546915][ T428] ? lock_acquire (kernel/locking/lockdep.c:5822)
[ 31.547071][ T428] ? blocking_notifier_call_chain (kernel/notifier.c:380 kernel/notifier.c:368)
[ 31.547256][ T428] down_read (./arch/x86/include/asm/preempt.h:79 kernel/locking/rwsem.c:1246 kernel/locking/rwsem.c:1261 kernel/locking/rwsem.c:1526)
[ 31.547379][ T428] ? blocking_notifier_call_chain (kernel/notifier.c:380 kernel/notifier.c:368)
[ 31.547565][ T428] ? __pfx_down_read (kernel/locking/rwsem.c:1522)
[ 31.547735][ T428] ? __mutex_unlock_slowpath (./arch/x86/include/asm/atomic64_64.h:101 ./include/linux/atomic/atomic-arch-fallback.h:4329 ./include/linux/atomic/atomic-long.h:1506 ./include/linux/atomic/atomic-instrumented.h:4481 kernel/locking/mutex.c:913)
[ 31.547889][ T428] blocking_notifier_call_chain (kernel/notifier.c:380 kernel/notifier.c:368)
[ 31.548041][ T428] __netdev_upper_dev_unlink (net/core/dev.c:8000 (discriminator 11) net/core/dev.c:8017 (discriminator 11) net/core/dev.c:8167 (discriminator 11))
[ 31.548193][ T428] ? __pfx___netdev_upper_dev_unlink (net/core/dev.c:8151)
[ 31.548400][ T428] ? synchronize_rcu_expedited (kernel/rcu/tree_exp.h:995 (discriminator 1))
[ 31.548596][ T428] ? __pfx_autoremove_wake_function (kernel/sched/wait.c:383)
[ 31.548946][ T428] ? __pfx___mutex_unlock_slowpath (kernel/locking/mutex.c:890)
[ 31.549143][ T428] netdev_upper_dev_unlink (net/core/dev.c:8190)
[ 31.549292][ T428] ? __pfx_netdev_upper_dev_unlink (net/core/dev.c:8190)
[ 31.549483][ T428] ? mutex_is_locked (./arch/x86/include/asm/atomic64_64.h:15 ./include/linux/atomic/atomic-arch-fallback.h:2583 ./include/linux/atomic/atomic-long.h:38 ./include/linux/atomic/atomic-instrumented.h:3189 kernel/locking/mutex.h:47 kernel/locking/mutex.c:66)
[ 31.549665][ T428] ? rtnl_is_locked (net/core/rtnetlink.c:164)
[ 31.549826][ T428] ? netdev_master_upper_dev_get (net/core/dev.c:7230)
[ 31.550011][ T428] ovs_netdev_detach_dev (net/openvswitch/vport-netdev.c:158 (discriminator 11)) openvswitch
[ 31.550247][ T428] ? ovs_netdev_get_vport (net/openvswitch/vport-netdev.c:196 (discriminator 3)) openvswitch
[ 31.550478][ T428] dp_device_event (net/openvswitch/dp_notify.c:77) openvswitch
[ 31.550678][ T428] ? trace_notifier_run (./include/trace/events/notifier.h:59 (discriminator 37))
[ 31.550839][ T428] notifier_call_chain (kernel/notifier.c:85 (discriminator 2))
[ 31.550992][ T428] blocking_notifier_call_chain (kernel/notifier.c:381 kernel/notifier.c:368)
[ 31.551226][ T428] unregister_netdevice_many_notify (net/core/dev.c:11571)
[ 31.551450][ T428] ? __pfx_unregister_netdevice_many_notify (net/core/dev.c:11512)
[ 31.551664][ T428] ? rtnl_dellink (net/core/rtnetlink.c:3512)
[ 31.551818][ T428] ? sock_def_readable (./include/linux/rcupdate.h:347 ./include/linux/rcupdate.h:880 net/core/sock.c:3479)
[ 31.551995][ T428] ? rtnl_is_locked (net/core/rtnetlink.c:164)
[ 31.552157][ T428] ? unregister_netdevice_queue (net/core/dev.c:11497)
[ 31.552386][ T428] ? __pfx_unregister_netdevice_queue (net/core/dev.c:11496)
[ 31.552568][ T428] ? __pfx_unregister_netdevice_queue (net/core/dev.c:11496)
[ 31.552768][ T428] rtnl_dellink (net/core/rtnetlink.c:3478 net/core/rtnetlink.c:3518)
[ 31.552925][ T428] ? __pfx_rtnl_dellink (net/core/rtnetlink.c:3484)
[ 31.553087][ T428] ? find_held_lock (kernel/locking/lockdep.c:5339)
[ 31.553238][ T428] ? __lock_release (kernel/locking/lockdep.c:5525)
[ 31.553418][ T428] ? rtnetlink_rcv_msg (./include/linux/rcupdate.h:347 ./include/linux/rcupdate.h:880 net/core/rtnetlink.c:6900)
[ 31.553568][ T428] ? __pfx___lock_release (kernel/locking/lockdep.c:5501)
[ 31.553740][ T428] ? __pfx_lock_acquire.part.0 (kernel/locking/lockdep.c:5814)
[ 31.553891][ T428] ? rtnetlink_rcv_msg (./include/linux/rcupdate.h:347 ./include/linux/rcupdate.h:880 net/core/rtnetlink.c:6900)
[ 31.554038][ T428] ? __pfx_rtnl_dellink (net/core/rtnetlink.c:3484)
[ 31.554191][ T428] rtnetlink_rcv_msg (net/core/rtnetlink.c:6902)
[ 31.554340][ T428] ? __pfx_rtnetlink_rcv_msg (net/core/rtnetlink.c:6805)
[ 31.554504][ T428] ? 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)
[ 31.554686][ T428] ? mark_lock (kernel/locking/lockdep.c:4727 (discriminator 3))
[ 31.554811][ T428] ? __lock_acquire (kernel/locking/lockdep.c:5226)
[ 31.554959][ T428] netlink_rcv_skb (net/netlink/af_netlink.c:2543)
[ 31.555121][ T428] ? __pfx_rtnetlink_rcv_msg (net/core/rtnetlink.c:6805)
[ 31.555268][ T428] ? __pfx_netlink_rcv_skb (net/netlink/af_netlink.c:2520)
[ 31.555420][ T428] ? netlink_deliver_tap (./include/linux/rcupdate.h:347 ./include/linux/rcupdate.h:880 net/netlink/af_netlink.c:340)
[ 31.555575][ T428] ? netlink_deliver_tap (./include/linux/rcupdate.h:347 ./include/linux/rcupdate.h:880 ./include/net/netns/generic.h:48 net/netlink/af_netlink.c:333)
[ 31.555751][ T428] netlink_unicast (net/netlink/af_netlink.c:1322 net/netlink/af_netlink.c:1348)
[ 31.555909][ T428] ? __pfx_netlink_unicast (net/netlink/af_netlink.c:1333)
[ 31.556070][ T428] ? find_held_lock (kernel/locking/lockdep.c:5339)
[ 31.556237][ T428] netlink_sendmsg (net/netlink/af_netlink.c:1892)
[ 31.556386][ T428] ? __pfx_netlink_sendmsg (net/netlink/af_netlink.c:1811)
[ 31.556536][ T428] ____sys_sendmsg (net/socket.c:711 net/socket.c:726 net/socket.c:2594)
[ 31.556697][ T428] ? __pfx_____sys_sendmsg (net/socket.c:2540)
[ 31.556867][ T428] ? __pfx_copy_msghdr_from_user (net/socket.c:2520)
[ 31.557053][ T428] ___sys_sendmsg (net/socket.c:2650)
[ 31.557204][ T428] ? __pfx____sys_sendmsg (net/socket.c:2637)
[ 31.557355][ T428] ? kasan_save_stack (mm/kasan/common.c:49)
[ 31.557507][ T428] ? kasan_save_stack (mm/kasan/common.c:48)
[ 31.557654][ T428] ? __kasan_record_aux_stack (mm/kasan/generic.c:544)
[ 31.557806][ T428] ? __call_rcu_common.constprop.0 (./arch/x86/include/asm/irqflags.h:26 ./arch/x86/include/asm/irqflags.h:87 ./arch/x86/include/asm/irqflags.h:123 kernel/rcu/tree.c:3087)
[ 31.558019][ T428] ? __x64_sys_close (fs/open.c:1557 fs/open.c:1539 fs/open.c:1539)
[ 31.558173][ T428] ? do_syscall_64 (arch/x86/entry/common.c:52 arch/x86/entry/common.c:83)
[ 31.558324][ T428] ? entry_SYSCALL_64_after_hwframe (arch/x86/entry/entry_64.S:130)
[ 31.558511][ T428] ? __lock_acquire (kernel/locking/lockdep.c:5226)
[ 31.558685][ T428] ? find_held_lock (kernel/locking/lockdep.c:5339)
[ 31.558839][ T428] ? __lock_release (kernel/locking/lockdep.c:5525)
[ 31.558987][ T428] ? __virt_addr_valid (./include/linux/rcupdate.h:347 ./include/linux/rcupdate.h:962 ./include/linux/mmzone.h:2058 arch/x86/mm/physaddr.c:65)
[ 31.559156][ T428] ? __pfx___lock_release (kernel/locking/lockdep.c:5501)
[ 31.559305][ T428] ? __pfx_lock_acquire.part.0 (kernel/locking/lockdep.c:5814)
[ 31.559455][ T428] __sys_sendmsg (net/socket.c:2680)
[ 31.559608][ T428] ? __pfx___sys_sendmsg (net/socket.c:2665)
[ 31.559762][ T428] ? __pfx_slab_free_after_rcu_debug (mm/slub.c:4643)
[ 31.559957][ T428] do_syscall_64 (arch/x86/entry/common.c:52 arch/x86/entry/common.c:83)
[ 31.560109][ T428] entry_SYSCALL_64_after_hwframe (arch/x86/entry/entry_64.S:130)
[   31.560293][  T428] RIP: 0033:0x7f91c693f9a7
[ 31.560478][ T428] Code: 0a 00 f7 d8 64 89 02 48 c7 c0 ff ff ff ff eb b9 0f 1f 00 f3 0f 1e fa 64 8b 04 25 18 00 00 00 85 c0 75 10 b8 2e 00 00 00 0f 05 <48> 3d 00 f0 ff ff 77 51 c3 48 83 ec 28 89 54 24 1c 48 89 74 24 10
All code
========
   0:	0a 00                	or     (%rax),%al
   2:	f7 d8                	neg    %eax
   4:	64 89 02             	mov    %eax,%fs:(%rdx)
   7:	48 c7 c0 ff ff ff ff 	mov    $0xffffffffffffffff,%rax
   e:	eb b9                	jmp    0xffffffffffffffc9
  10:	0f 1f 00             	nopl   (%rax)
  13:	f3 0f 1e fa          	endbr64
  17:	64 8b 04 25 18 00 00 	mov    %fs:0x18,%eax
  1e:	00 
  1f:	85 c0                	test   %eax,%eax
  21:	75 10                	jne    0x33
  23:	b8 2e 00 00 00       	mov    $0x2e,%eax
  28:	0f 05                	syscall
  2a:*	48 3d 00 f0 ff ff    	cmp    $0xfffffffffffff000,%rax		<-- trapping instruction
  30:	77 51                	ja     0x83
  32:	c3                   	ret
  33:	48 83 ec 28          	sub    $0x28,%rsp
  37:	89 54 24 1c          	mov    %edx,0x1c(%rsp)
  3b:	48 89 74 24 10       	mov    %rsi,0x10(%rsp)

Code starting with the faulting instruction
===========================================
   0:	48 3d 00 f0 ff ff    	cmp    $0xfffffffffffff000,%rax
   6:	77 51                	ja     0x59
   8:	c3                   	ret
   9:	48 83 ec 28          	sub    $0x28,%rsp
   d:	89 54 24 1c          	mov    %edx,0x1c(%rsp)
  11:	48 89 74 24 10       	mov    %rsi,0x10(%rsp)
[   31.561028][  T428] RSP: 002b:00007ffc5da63748 EFLAGS: 00000246 ORIG_RAX: 000000000000002e
[   31.561282][  T428] RAX: ffffffffffffffda RBX: 00007ffc5da63e70 RCX: 00007f91c693f9a7
[   31.561513][  T428] RDX: 0000000000000000 RSI: 00007ffc5da637b0 RDI: 0000000000000005
[   31.561738][  T428] RBP: 0000000000000001 R08: 0000000000000003 R09: 0000000000000078
[   31.561975][  T428] R10: 00007f91c67fdef8 R11: 0000000000000246 R12: 0000000000000001


Finger prints:
print_deadlock_bug:validate_chain:__lock_acquire:down_read:blocking_notifier_call_chain