======================================
| [4358.773704][T19439] #0: ffffffffb9607e88 (rtnl_mutex){+.+.}-{4:4}, at: rtnl_dellink (net/core/rtnetlink.c:3521)
| [4358.773969][T19439] #1: ffffffffb95f6a70 ((netdev_chain).rwsem){++++}-{4:4}, at: blocking_notifier_call_chain (kernel/notifier.c:380 kernel/notifier.c:368)
| [ 4358.774269][T19439]
| [ 4358.774269][T19439] stack backtrace:
[ 4358.774677][T19439] Hardware name: Bochs Bochs, BIOS Bochs 01/01/2011
[ 4358.774860][T19439] Call Trace:
[ 4358.774971][T19439]  <TASK>
[4358.775048][T19439] dump_stack_lvl (lib/dump_stack.c:123)
[4358.775199][T19439] print_deadlock_bug (kernel/locking/lockdep.c:3040)
[4358.775346][T19439] validate_chain (kernel/locking/lockdep.c:3894)
[4358.775496][T19439] ? __pfx_validate_chain (kernel/locking/lockdep.c:3860)
[4358.775645][T19439] ? 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)
[4358.775787][T19439] ? mark_lock (kernel/locking/lockdep.c:4727 (discriminator 3))
[4358.775899][T19439] __lock_acquire (kernel/locking/lockdep.c:5226)
[4358.776043][T19439] ? spin_bug (./include/linux/pid.h:232 kernel/locking/spinlock_debug.c:64 kernel/locking/spinlock_debug.c:78)
[4358.776155][T19439] ? debug_object_assert_init (./include/linux/err.h:81 lib/debugobjects.c:1010)
[4358.776306][T19439] lock_acquire.part.0 (kernel/locking/lockdep.c:467 kernel/locking/lockdep.c:5851)
[4358.776449][T19439] ? blocking_notifier_call_chain (kernel/notifier.c:380 kernel/notifier.c:368)
[4358.776631][T19439] ? __pfx_lock_acquire.part.0 (kernel/locking/lockdep.c:5814)
[4358.776777][T19439] ? trace_lock_acquire (./include/trace/events/lock.h:24 (discriminator 37))
[4358.776928][T19439] ? lock_acquire (kernel/locking/lockdep.c:5822)
[4358.777071][T19439] ? blocking_notifier_call_chain (kernel/notifier.c:380 kernel/notifier.c:368)
[4358.777250][T19439] down_read (./arch/x86/include/asm/preempt.h:79 kernel/locking/rwsem.c:1246 kernel/locking/rwsem.c:1261 kernel/locking/rwsem.c:1526)
[4358.777362][T19439] ? blocking_notifier_call_chain (kernel/notifier.c:380 kernel/notifier.c:368)
[4358.777541][T19439] ? __pfx_down_read (kernel/locking/rwsem.c:1522)
[4358.777686][T19439] blocking_notifier_call_chain (kernel/notifier.c:380 kernel/notifier.c:368)
[4358.777832][T19439] __dev_close_many (net/core/dev.c:1537 (discriminator 3))
[4358.777980][T19439] ? __pfx___dev_close_many (net/core/dev.c:1525)
[4358.778133][T19439] dev_close_many (net/core/dev.c:1588)
[4358.778277][T19439] ? __pfx_dev_close_many (net/core/dev.c:1578)
[4358.778421][T19439] ? ipv6_mc_down (net/ipv6/mcast.c:1140 net/ipv6/mcast.c:2777)
[4358.778570][T19439] vlan_device_event (net/8021q/vlan.c:451)
[4358.778717][T19439] ? __pfx_vlan_device_event (net/8021q/vlan.c:362)
[4358.778862][T19439] ? __pfx_br_device_event (net/bridge/br.c:29)
[4358.779013][T19439] ? packet_notifier (net/packet/af_packet.c:4282)
[4358.779160][T19439] notifier_call_chain (kernel/notifier.c:85 (discriminator 2))
[4358.779306][T19439] blocking_notifier_call_chain (kernel/notifier.c:381 kernel/notifier.c:368)
[4358.779449][T19439] dev_close_many (net/core/dev.c:1591)
[4358.779594][T19439] ? find_held_lock (kernel/locking/lockdep.c:5339)
[4358.779737][T19439] ? __pfx_dev_close_many (net/core/dev.c:1578)
[4358.779881][T19439] ? __lock_release (kernel/locking/lockdep.c:5525)
[4358.780032][T19439] ? __pfx___lock_release (kernel/locking/lockdep.c:5501)
[4358.780176][T19439] ? __pfx_lock_acquire.part.0 (kernel/locking/lockdep.c:5814)
[4358.780321][T19439] unregister_netdevice_many_notify (net/core/dev.c:11549)
[4358.780501][T19439] ? 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)
[4358.780645][T19439] ? mark_lock (kernel/locking/lockdep.c:4727 (discriminator 3))
[4358.780756][T19439] ? __pfx_unregister_netdevice_many_notify (net/core/dev.c:11516)
[4358.780934][T19439] ? __pfx_kernfs_free_rcu (fs/kernfs/dir.c:533)
[4358.781083][T19439] ? lockdep_hardirqs_on_prepare (kernel/locking/lockdep.c:4347 kernel/locking/lockdep.c:4406)
[4358.781262][T19439] ? 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)
[4358.781409][T19439] ? rtnl_is_locked (net/core/rtnetlink.c:163)
[4358.781552][T19439] ? unregister_netdevice_queue (net/core/dev.c:11501)
[4358.781732][T19439] ? __pfx_unregister_netdevice_queue (net/core/dev.c:11500)
[4358.781915][T19439] ? br_dev_delete (net/bridge/br_if.c:396)
[4358.782062][T19439] rtnl_dellink (net/core/rtnetlink.c:3487 net/core/rtnetlink.c:3527)
[4358.782212][T19439] ? __pfx_rtnl_dellink (net/core/rtnetlink.c:3493)
[4358.782371][T19439] ? find_held_lock (kernel/locking/lockdep.c:5339)
[4358.782514][T19439] ? __lock_release (kernel/locking/lockdep.c:5525)
[4358.782657][T19439] ? rtnetlink_rcv_msg (./include/linux/rcupdate.h:347 ./include/linux/rcupdate.h:880 net/core/rtnetlink.c:6909)
[4358.782802][T19439] ? __pfx___lock_release (kernel/locking/lockdep.c:5501)
[4358.782946][T19439] ? __pfx_lock_acquire.part.0 (kernel/locking/lockdep.c:5814)
[4358.783093][T19439] ? rtnetlink_rcv_msg (./include/linux/rcupdate.h:347 ./include/linux/rcupdate.h:880 net/core/rtnetlink.c:6909)
[4358.783242][T19439] ? __pfx_rtnl_dellink (net/core/rtnetlink.c:3493)
[4358.783388][T19439] rtnetlink_rcv_msg (net/core/rtnetlink.c:6911)
[4358.783533][T19439] ? __pfx_rtnetlink_rcv_msg (net/core/rtnetlink.c:6814)
[4358.783678][T19439] ? 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)
[4358.783821][T19439] ? mark_lock (kernel/locking/lockdep.c:4727 (discriminator 3))
[4358.783932][T19439] ? __lock_acquire (kernel/locking/lockdep.c:5226)
[4358.784078][T19439] netlink_rcv_skb (net/netlink/af_netlink.c:2543)
[4358.784226][T19439] ? __pfx_rtnetlink_rcv_msg (net/core/rtnetlink.c:6814)
[4358.784376][T19439] ? __pfx_netlink_rcv_skb (net/netlink/af_netlink.c:2520)
[4358.784523][T19439] ? netlink_deliver_tap (./include/linux/rcupdate.h:347 ./include/linux/rcupdate.h:880 net/netlink/af_netlink.c:340)
[4358.784668][T19439] ? 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)
[4358.784816][T19439] netlink_unicast (net/netlink/af_netlink.c:1322 net/netlink/af_netlink.c:1348)
[4358.784962][T19439] ? __pfx_netlink_unicast (net/netlink/af_netlink.c:1333)
[4358.785107][T19439] ? find_held_lock (kernel/locking/lockdep.c:5339)
[4358.785250][T19439] netlink_sendmsg (net/netlink/af_netlink.c:1892)
[4358.785399][T19439] ? __pfx_netlink_sendmsg (net/netlink/af_netlink.c:1811)
[4358.785546][T19439] ____sys_sendmsg (net/socket.c:711 net/socket.c:726 net/socket.c:2594)
[4358.785692][T19439] ? __pfx_____sys_sendmsg (net/socket.c:2540)
[4358.785836][T19439] ? __pfx_copy_msghdr_from_user (net/socket.c:2520)
[4358.786021][T19439] ___sys_sendmsg (net/socket.c:2650)
[4358.786165][T19439] ? __pfx____sys_sendmsg (net/socket.c:2637)
[4358.786310][T19439] ? kasan_save_stack (mm/kasan/common.c:49)
[4358.786459][T19439] ? kasan_save_stack (mm/kasan/common.c:48)
[4358.786603][T19439] ? __kasan_record_aux_stack (mm/kasan/generic.c:544)
[4358.786748][T19439] ? __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)
[4358.786927][T19439] ? __x64_sys_close (fs/open.c:1557 fs/open.c:1539 fs/open.c:1539)
[4358.787075][T19439] ? do_syscall_64 (arch/x86/entry/common.c:52 arch/x86/entry/common.c:83)
[4358.787222][T19439] ? entry_SYSCALL_64_after_hwframe (arch/x86/entry/entry_64.S:130)
[4358.787400][T19439] ? __lock_acquire (kernel/locking/lockdep.c:5226)
[4358.787550][T19439] ? find_held_lock (kernel/locking/lockdep.c:5339)
[4358.787693][T19439] ? __lock_release (kernel/locking/lockdep.c:5525)
[4358.787837][T19439] ? __virt_addr_valid (./include/linux/rcupdate.h:347 ./include/linux/rcupdate.h:962 ./include/linux/mmzone.h:2058 arch/x86/mm/physaddr.c:65)
[4358.788078][T19439] ? __pfx___lock_release (kernel/locking/lockdep.c:5501)
[4358.788223][T19439] ? __pfx_lock_acquire.part.0 (kernel/locking/lockdep.c:5814)
[4358.788369][T19439] __sys_sendmsg (net/socket.c:2680)
[4358.788514][T19439] ? __pfx___sys_sendmsg (net/socket.c:2665)
[4358.788747][T19439] ? __pfx_slab_free_after_rcu_debug (mm/slub.c:4643)
[4358.788932][T19439] do_syscall_64 (arch/x86/entry/common.c:52 arch/x86/entry/common.c:83)
[4358.789075][T19439] entry_SYSCALL_64_after_hwframe (arch/x86/entry/entry_64.S:130)
[ 4358.789337][T19439] RIP: 0033:0x7f64efd609a7
[ 4358.789486][T19439] 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)
[ 4358.790084][T19439] RSP: 002b:00007fff65b279e8 EFLAGS: 00000246 ORIG_RAX: 000000000000002e
[ 4358.790301][T19439] RAX: ffffffffffffffda RBX: 00007fff65b28110 RCX: 00007f64efd609a7
[ 4358.790520][T19439] RDX: 0000000000000000 RSI: 00007fff65b27a50 RDI: 0000000000000005
[ 4358.790822][T19439] RBP: 0000000000000001 R08: 0000000000000003 R09: 0000000000000078
[ 4358.791041][T19439] R10: 00007f64efc1eef8 R11: 0000000000000246 R12: 0000000000000001


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