======================================
| [ 14.796676][ T320] #0: ffffffffacc07e88 (rtnl_mutex){+.+.}-{4:4}, at: rtnl_newlink (net/core/rtnetlink.c:328 net/core/rtnetlink.c:4011)
| [ 14.796937][ T320] #1: ffffffffacbf6a70 ((netdev_chain).rwsem){++++}-{4:4}, at: blocking_notifier_call_chain (kernel/notifier.c:380 kernel/notifier.c:368)
| [   14.797243][  T320]
| [   14.797243][  T320] stack backtrace:
[   14.797646][  T320] Hardware name: Bochs Bochs, BIOS Bochs 01/01/2011
[   14.797835][  T320] Call Trace:
[   14.797946][  T320]  <TASK>
[ 14.798021][ T320] dump_stack_lvl (lib/dump_stack.c:123)
[ 14.798172][ T320] print_deadlock_bug (kernel/locking/lockdep.c:3040)
[ 14.798322][ T320] validate_chain (kernel/locking/lockdep.c:3894)
[ 14.798471][ T320] ? __pfx_validate_chain (kernel/locking/lockdep.c:3860)
[ 14.798617][ T320] ? 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)
[ 14.798762][ T320] ? mark_lock (kernel/locking/lockdep.c:4727 (discriminator 3))
[ 14.798872][ T320] __lock_acquire (kernel/locking/lockdep.c:5226)
[ 14.799023][ T320] lock_acquire.part.0 (kernel/locking/lockdep.c:467 kernel/locking/lockdep.c:5851)
[ 14.799172][ T320] ? blocking_notifier_call_chain (kernel/notifier.c:380 kernel/notifier.c:368)
[ 14.799351][ T320] ? __pfx_lock_acquire.part.0 (kernel/locking/lockdep.c:5814)
[ 14.799500][ T320] ? trace_lock_acquire (./include/trace/events/lock.h:24 (discriminator 37))
[ 14.799649][ T320] ? lock_acquire (kernel/locking/lockdep.c:5822)
[ 14.799794][ T320] ? blocking_notifier_call_chain (kernel/notifier.c:380 kernel/notifier.c:368)
[ 14.799984][ T320] down_read (./arch/x86/include/asm/preempt.h:79 kernel/locking/rwsem.c:1246 kernel/locking/rwsem.c:1261 kernel/locking/rwsem.c:1526)
[ 14.800094][ T320] ? blocking_notifier_call_chain (kernel/notifier.c:380 kernel/notifier.c:368)
[ 14.800274][ T320] ? __pfx_down_read (kernel/locking/rwsem.c:1522)
[ 14.800421][ T320] blocking_notifier_call_chain (kernel/notifier.c:380 kernel/notifier.c:368)
[ 14.800565][ T320] netdev_update_features (net/core/dev.c:10314)
[ 14.800711][ T320] ? __pfx_netdev_update_features (net/core/dev.c:10311)
[ 14.800897][ T320] vlan_device_event (net/8021q/vlan.c:430 (discriminator 2))
[ 14.801051][ T320] ? __pfx_vlan_device_event (net/8021q/vlan.c:362)
[ 14.801198][ T320] ? __pfx_br_device_event (net/bridge/br.c:29)
[ 14.801343][ T320] ? packet_notifier (net/packet/af_packet.c:4282)
[ 14.801491][ T320] notifier_call_chain (kernel/notifier.c:85 (discriminator 2))
[ 14.801637][ T320] blocking_notifier_call_chain (kernel/notifier.c:381 kernel/notifier.c:368)
[ 14.801783][ T320] netdev_update_features (net/core/dev.c:10314)
[ 14.801931][ T320] ? __pfx_netdev_update_features (net/core/dev.c:10311)
[ 14.802114][ T320] br_add_if (net/bridge/br_if.c:657)
[ 14.802225][ T320] ? rtnl_is_locked (net/core/rtnetlink.c:164)
[ 14.802371][ T320] ? netdev_master_upper_dev_get (net/core/dev.c:7230)
[ 14.802552][ T320] do_setlink.constprop.0 (net/core/rtnetlink.c:3116)
[ 14.802700][ T320] ? __pfx_do_setlink.constprop.0 (net/core/rtnetlink.c:2990)
[ 14.802880][ T320] ? lock_acquire.part.0 (kernel/locking/lockdep.c:467 kernel/locking/lockdep.c:5851)
[ 14.803026][ T320] ? rtnl_newlink (net/core/rtnetlink.c:328 net/core/rtnetlink.c:4011)
[ 14.803171][ T320] ? rtnl_newlink (./include/linux/slab.h:901 net/core/rtnetlink.c:3912)
[ 14.803316][ T320] ? rtnetlink_rcv_msg (net/core/rtnetlink.c:6902)
[ 14.803459][ T320] ? __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)
[ 14.803606][ T320] ? __pfx___mutex_trylock_common (kernel/locking/mutex.c:79)
[ 14.803790][ T320] ? lock_acquire (kernel/locking/lockdep.c:5822)
[ 14.803935][ T320] ? trace_contention_end (./include/trace/events/lock.h:122 (discriminator 37))
[ 14.804084][ T320] ? __mutex_lock (./arch/x86/include/asm/preempt.h:94 kernel/locking/mutex.c:595 kernel/locking/mutex.c:735)
[ 14.804230][ T320] ? __pfx_do_raw_spin_lock (kernel/locking/spinlock_debug.c:114)
[ 14.804377][ T320] ? rtnl_newlink (net/core/rtnetlink.c:328 net/core/rtnetlink.c:4011)
[ 14.804522][ T320] ? __pfx___mutex_lock (kernel/locking/mutex.c:734)
[ 14.804668][ T320] ? __rtnl_newlink (net/core/rtnetlink.c:3862)
[ 14.804814][ T320] rtnl_newlink (net/core/rtnetlink.c:336 net/core/rtnetlink.c:4013)
[ 14.804961][ T320] ? __pfx_rtnl_newlink (net/core/rtnetlink.c:3903)
[ 14.805105][ T320] ? find_held_lock (kernel/locking/lockdep.c:5339)
[ 14.805255][ T320] ? __pfx___lock_release (kernel/locking/lockdep.c:5501)
[ 14.805399][ T320] ? __pfx_lock_acquire.part.0 (kernel/locking/lockdep.c:5814)
[ 14.805549][ T320] ? rtnetlink_rcv_msg (./include/linux/rcupdate.h:347 ./include/linux/rcupdate.h:880 net/core/rtnetlink.c:6900)
[ 14.805694][ T320] ? __pfx_rtnl_newlink (net/core/rtnetlink.c:3903)
[ 14.805839][ T320] rtnetlink_rcv_msg (net/core/rtnetlink.c:6902)
[ 14.805983][ T320] ? __pfx_rtnetlink_rcv_msg (net/core/rtnetlink.c:6805)
[ 14.806131][ T320] ? 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)
[ 14.806279][ T320] ? mark_lock (kernel/locking/lockdep.c:4727 (discriminator 3))
[ 14.806391][ T320] ? __lock_acquire (kernel/locking/lockdep.c:5226)
[ 14.806537][ T320] netlink_rcv_skb (net/netlink/af_netlink.c:2543)
[ 14.806688][ T320] ? __pfx_rtnetlink_rcv_msg (net/core/rtnetlink.c:6805)
[ 14.806834][ T320] ? __pfx_netlink_rcv_skb (net/netlink/af_netlink.c:2520)
[ 14.806982][ T320] ? netlink_deliver_tap (./include/linux/rcupdate.h:347 ./include/linux/rcupdate.h:880 net/netlink/af_netlink.c:340)
[ 14.807128][ T320] ? 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)
[ 14.807291][ T320] netlink_unicast (net/netlink/af_netlink.c:1322 net/netlink/af_netlink.c:1348)
[ 14.807438][ T320] ? __pfx_netlink_unicast (net/netlink/af_netlink.c:1333)
[ 14.807582][ T320] ? find_held_lock (kernel/locking/lockdep.c:5339)
[ 14.807725][ T320] netlink_sendmsg (net/netlink/af_netlink.c:1892)
[ 14.807872][ T320] ? __pfx_netlink_sendmsg (net/netlink/af_netlink.c:1811)
[ 14.808019][ T320] ____sys_sendmsg (net/socket.c:711 net/socket.c:726 net/socket.c:2594)
[ 14.808163][ T320] ? __pfx_____sys_sendmsg (net/socket.c:2540)
[ 14.808310][ T320] ? __pfx_copy_msghdr_from_user (net/socket.c:2520)
[ 14.808494][ T320] ___sys_sendmsg (net/socket.c:2650)
[ 14.808639][ T320] ? __pfx____sys_sendmsg (net/socket.c:2637)
[ 14.808784][ T320] ? kasan_save_stack (mm/kasan/common.c:49)
[ 14.808930][ T320] ? kasan_save_stack (mm/kasan/common.c:48)
[ 14.809075][ T320] ? __kasan_record_aux_stack (mm/kasan/generic.c:544)
[ 14.809222][ T320] ? __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)
[ 14.809406][ T320] ? __x64_sys_close (fs/open.c:1557 fs/open.c:1539 fs/open.c:1539)
[ 14.809552][ T320] ? do_syscall_64 (arch/x86/entry/common.c:52 arch/x86/entry/common.c:83)
[ 14.809697][ T320] ? entry_SYSCALL_64_after_hwframe (arch/x86/entry/entry_64.S:130)
[ 14.809876][ T320] ? __lock_acquire (kernel/locking/lockdep.c:5226)
[ 14.810022][ T320] ? find_held_lock (kernel/locking/lockdep.c:5339)
[ 14.810167][ T320] ? __lock_release (kernel/locking/lockdep.c:5525)
[ 14.810312][ T320] ? __virt_addr_valid (./include/linux/rcupdate.h:347 ./include/linux/rcupdate.h:962 ./include/linux/mmzone.h:2058 arch/x86/mm/physaddr.c:65)
[ 14.810458][ T320] ? __pfx___lock_release (kernel/locking/lockdep.c:5501)
[ 14.810603][ T320] ? __pfx_lock_acquire.part.0 (kernel/locking/lockdep.c:5814)
[ 14.810751][ T320] __sys_sendmsg (net/socket.c:2680)
[ 14.810895][ T320] ? __pfx___sys_sendmsg (net/socket.c:2665)
[ 14.811039][ T320] ? __pfx_slab_free_after_rcu_debug (mm/slub.c:4643)
[ 14.811225][ T320] do_syscall_64 (arch/x86/entry/common.c:52 arch/x86/entry/common.c:83)
[ 14.811371][ T320] entry_SYSCALL_64_after_hwframe (arch/x86/entry/entry_64.S:130)
[   14.811554][  T320] RIP: 0033:0x7f05915fb9a7
[ 14.811707][ T320] 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)
[   14.812219][  T320] RSP: 002b:00007ffe4bcca2d8 EFLAGS: 00000246 ORIG_RAX: 000000000000002e
[   14.812437][  T320] RAX: ffffffffffffffda RBX: 00007ffe4bccaa10 RCX: 00007f05915fb9a7
[   14.812661][  T320] RDX: 0000000000000000 RSI: 00007ffe4bcca340 RDI: 0000000000000005
[   14.812877][  T320] RBP: 0000000000000005 R08: 0000000000000003 R09: 0000000000000000
[   14.813095][  T320] R10: 000000002d1ed910 R11: 0000000000000246 R12: 0000000000000005


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