======================================
| [ 56.850191][ T844] #0: ffffffffa57e7a48 (rtnl_mutex){+.+.}-{4:4}, at: rtnl_newlink (net/core/rtnetlink.c:337 net/core/rtnetlink.c:4020)
| [ 56.850466][ T844] #1: ffffffffa57d6630 ((netdev_chain).rwsem){++++}-{4:4}, at: blocking_notifier_call_chain (kernel/notifier.c:380 kernel/notifier.c:368)
| [   56.850775][  T844]
| [   56.850775][  T844] stack backtrace:
[   56.851203][  T844] Hardware name: Bochs Bochs, BIOS Bochs 01/01/2011
[   56.851395][  T844] Call Trace:
[   56.851512][  T844]  <TASK>
[ 56.851593][ T844] dump_stack_lvl (lib/dump_stack.c:123)
[ 56.851757][ T844] print_deadlock_bug (kernel/locking/lockdep.c:3040)
[ 56.851912][ T844] validate_chain (kernel/locking/lockdep.c:3894)
[ 56.852067][ T844] ? __pfx_validate_chain (kernel/locking/lockdep.c:3860)
[ 56.852223][ T844] ? 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)
[ 56.852379][ T844] ? mark_lock (kernel/locking/lockdep.c:4727 (discriminator 3))
[ 56.852495][ T844] __lock_acquire (kernel/locking/lockdep.c:5226)
[ 56.852650][ T844] lock_acquire.part.0 (kernel/locking/lockdep.c:467 kernel/locking/lockdep.c:5851)
[ 56.852803][ T844] ? blocking_notifier_call_chain (kernel/notifier.c:380 kernel/notifier.c:368)
[ 56.852998][ T844] ? __pfx_lock_acquire.part.0 (kernel/locking/lockdep.c:5814)
[ 56.853148][ T844] ? trace_lock_acquire (./include/trace/events/lock.h:24 (discriminator 37))
[ 56.853303][ T844] ? lock_acquire (kernel/locking/lockdep.c:5822)
[ 56.853455][ T844] ? blocking_notifier_call_chain (kernel/notifier.c:380 kernel/notifier.c:368)
[ 56.853642][ T844] down_read (./arch/x86/include/asm/preempt.h:79 kernel/locking/rwsem.c:1246 kernel/locking/rwsem.c:1261 kernel/locking/rwsem.c:1526)
[ 56.853757][ T844] ? blocking_notifier_call_chain (kernel/notifier.c:380 kernel/notifier.c:368)
[ 56.853944][ T844] ? __pfx_down_read (kernel/locking/rwsem.c:1522)
[ 56.854101][ T844] blocking_notifier_call_chain (kernel/notifier.c:380 kernel/notifier.c:368)
[ 56.854250][ T844] netdev_update_features (net/core/dev.c:10314)
[ 56.854405][ T844] ? __pfx_netdev_update_features (net/core/dev.c:10311)
[ 56.854595][ T844] vlan_device_event (net/8021q/vlan.c:430 (discriminator 2)) 8021q
[ 56.854787][ T844] ? __pfx_vlan_device_event (net/8021q/vlan.c:362) 8021q
[ 56.854976][ T844] ? packet_notifier (net/packet/af_packet.c:4282)
[ 56.855129][ T844] notifier_call_chain (kernel/notifier.c:85 (discriminator 2))
[ 56.855286][ T844] blocking_notifier_call_chain (kernel/notifier.c:381 kernel/notifier.c:368)
[ 56.855435][ T844] netdev_update_features (net/core/dev.c:10314)
[ 56.855584][ T844] ? __pfx_netdev_update_features (net/core/dev.c:10311)
[ 56.855771][ T844] ? lockdep_hardirqs_on_prepare (kernel/locking/lockdep.c:4347 kernel/locking/lockdep.c:4406)
[ 56.855957][ T844] ? br_del_if (net/bridge/br_if.c:748) bridge
[ 56.856156][ T844] br_del_if (net/bridge/br_if.c:753) bridge
[ 56.856351][ T844] ? rtnl_is_locked (net/core/rtnetlink.c:163)
[ 56.856503][ T844] do_set_master (net/core/rtnetlink.c:2912)
[ 56.856655][ T844] do_setlink.constprop.0 (net/core/rtnetlink.c:3125)
[ 56.856807][ T844] ? __pfx_do_setlink.constprop.0 (net/core/rtnetlink.c:2999)
[ 56.856996][ T844] ? lock_acquire.part.0 (kernel/locking/lockdep.c:467 kernel/locking/lockdep.c:5851)
[ 56.857147][ T844] ? rtnl_newlink (net/core/rtnetlink.c:337 net/core/rtnetlink.c:4020)
[ 56.857299][ T844] ? rtnl_newlink (./include/linux/slab.h:901 net/core/rtnetlink.c:3921)
[ 56.857450][ T844] ? rtnetlink_rcv_msg (net/core/rtnetlink.c:6911)
[ 56.857604][ T844] ? __mutex_trylock_common (./arch/x86/include/asm/atomic64_64.h:101 ./include/linux/atomic/atomic-arch-fallback.h:4296 ./include/linux/atomic/atomic-long.h:1482 ./include/linux/atomic/atomic-instrumented.h:4458 kernel/locking/mutex.c:104)
[ 56.857756][ T844] ? __pfx___mutex_trylock_common (kernel/locking/mutex.c:79)
[ 56.857942][ T844] ? lock_acquire (kernel/locking/lockdep.c:5822)
[ 56.858092][ T844] ? trace_contention_end (./include/trace/events/lock.h:122 (discriminator 37))
[ 56.858243][ T844] ? __mutex_lock (./arch/x86/include/asm/preempt.h:94 kernel/locking/mutex.c:595 kernel/locking/mutex.c:735)
[ 56.858397][ T844] ? __pfx_do_raw_spin_lock (kernel/locking/spinlock_debug.c:114)
[ 56.858552][ T844] ? rtnl_newlink (net/core/rtnetlink.c:337 net/core/rtnetlink.c:4020)
[ 56.858700][ T844] ? __pfx___mutex_lock (kernel/locking/mutex.c:734)
[ 56.858851][ T844] ? __rtnl_newlink (net/core/rtnetlink.c:3871)
[ 56.859002][ T844] rtnl_newlink (net/core/rtnetlink.c:345 net/core/rtnetlink.c:4022)
[ 56.859152][ T844] ? __pfx_rtnl_newlink (net/core/rtnetlink.c:3912)
[ 56.859304][ T844] ? find_held_lock (kernel/locking/lockdep.c:5339)
[ 56.859459][ T844] ? __pfx___lock_release (kernel/locking/lockdep.c:5501)
[ 56.859610][ T844] ? __pfx_lock_acquire.part.0 (kernel/locking/lockdep.c:5814)
[ 56.859769][ T844] ? rtnetlink_rcv_msg (./include/linux/rcupdate.h:347 ./include/linux/rcupdate.h:880 net/core/rtnetlink.c:6909)
[ 56.859918][ T844] ? __pfx_rtnl_newlink (net/core/rtnetlink.c:3912)
[ 56.860069][ T844] rtnetlink_rcv_msg (net/core/rtnetlink.c:6911)
[ 56.860219][ T844] ? __pfx_rtnetlink_rcv_msg (net/core/rtnetlink.c:6814)
[ 56.860371][ T844] ? 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)
[ 56.860518][ T844] ? mark_lock (kernel/locking/lockdep.c:4727 (discriminator 3))
[ 56.860635][ T844] ? __lock_acquire (kernel/locking/lockdep.c:5226)
[ 56.860787][ T844] netlink_rcv_skb (net/netlink/af_netlink.c:2543)
[ 56.860954][ T844] ? __pfx_rtnetlink_rcv_msg (net/core/rtnetlink.c:6814)
[ 56.861104][ T844] ? __pfx_netlink_rcv_skb (net/netlink/af_netlink.c:2520)
[ 56.861259][ T844] ? netlink_deliver_tap (./include/linux/rcupdate.h:347 ./include/linux/rcupdate.h:880 net/netlink/af_netlink.c:340)
[ 56.861416][ T844] ? 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)
[ 56.861566][ T844] netlink_unicast (net/netlink/af_netlink.c:1322 net/netlink/af_netlink.c:1348)
[ 56.861715][ T844] ? __pfx_netlink_unicast (net/netlink/af_netlink.c:1333)
[ 56.861874][ T844] ? find_held_lock (kernel/locking/lockdep.c:5339)
[ 56.862026][ T844] netlink_sendmsg (net/netlink/af_netlink.c:1892)
[ 56.862176][ T844] ? __pfx_netlink_sendmsg (net/netlink/af_netlink.c:1811)
[ 56.862332][ T844] ____sys_sendmsg (net/socket.c:711 net/socket.c:726 net/socket.c:2594)
[ 56.862485][ T844] ? __pfx_____sys_sendmsg (net/socket.c:2540)
[ 56.862634][ T844] ? __pfx_copy_msghdr_from_user (net/socket.c:2520)
[ 56.862824][ T844] ___sys_sendmsg (net/socket.c:2650)
[ 56.862974][ T844] ? __pfx____sys_sendmsg (net/socket.c:2637)
[ 56.863132][ T844] ? kasan_save_stack (mm/kasan/common.c:49)
[ 56.863288][ T844] ? kasan_save_stack (mm/kasan/common.c:48)
[ 56.863436][ T844] ? __kasan_record_aux_stack (mm/kasan/generic.c:544)
[ 56.863585][ T844] ? __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)
[ 56.863777][ T844] ? __x64_sys_close (fs/open.c:1557 fs/open.c:1539 fs/open.c:1539)
[ 56.863929][ T844] ? do_syscall_64 (arch/x86/entry/common.c:52 arch/x86/entry/common.c:83)
[ 56.864080][ T844] ? entry_SYSCALL_64_after_hwframe (arch/x86/entry/entry_64.S:130)
[ 56.864285][ T844] ? __lock_acquire (kernel/locking/lockdep.c:5226)
[ 56.864438][ T844] ? find_held_lock (kernel/locking/lockdep.c:5339)
[ 56.864587][ T844] ? __lock_release (kernel/locking/lockdep.c:5525)
[ 56.864736][ T844] ? __virt_addr_valid (./include/linux/rcupdate.h:347 ./include/linux/rcupdate.h:962 ./include/linux/mmzone.h:2058 arch/x86/mm/physaddr.c:65)
[ 56.864889][ T844] ? __pfx___lock_release (kernel/locking/lockdep.c:5501)
[ 56.865037][ T844] ? __pfx_lock_acquire.part.0 (kernel/locking/lockdep.c:5814)
[ 56.865188][ T844] __sys_sendmsg (net/socket.c:2680)
[ 56.865350][ T844] ? __pfx___sys_sendmsg (net/socket.c:2665)
[ 56.865501][ T844] ? __pfx_slab_free_after_rcu_debug (mm/slub.c:4643)
[ 56.865693][ T844] do_syscall_64 (arch/x86/entry/common.c:52 arch/x86/entry/common.c:83)
[ 56.865844][ T844] entry_SYSCALL_64_after_hwframe (arch/x86/entry/entry_64.S:130)
[   56.866029][  T844] RIP: 0033:0x7f8678fe99a7
[ 56.866191][ T844] 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)
[   56.866731][  T844] RSP: 002b:00007fff99c827a8 EFLAGS: 00000246 ORIG_RAX: 000000000000002e
[   56.866961][  T844] RAX: ffffffffffffffda RBX: 00007fff99c82ed0 RCX: 00007f8678fe99a7
[   56.867187][  T844] RDX: 0000000000000000 RSI: 00007fff99c82810 RDI: 0000000000000005
[   56.867421][  T844] RBP: 0000000000000003 R08: 0000000000000003 R09: 0000000000000078
[   56.867646][  T844] R10: 00007f8678ea7ef8 R11: 0000000000000246 R12: 0000000000000003


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