======================================
| [ 15.314296][ T321] #0: ffffffffb9e07e88 (rtnl_mutex){+.+.}-{4:4}, at: rtnl_newlink (net/core/rtnetlink.c:337 net/core/rtnetlink.c:4020)
| [ 15.314558][ T321] #1: ffffffffb9df6a70 ((netdev_chain).rwsem){++++}-{4:4}, at: blocking_notifier_call_chain (kernel/notifier.c:380 kernel/notifier.c:368)
| [   15.314861][  T321]
| [   15.314861][  T321] stack backtrace:
[   15.315261][  T321] Hardware name: Bochs Bochs, BIOS Bochs 01/01/2011
[   15.315443][  T321] Call Trace:
[   15.315585][  T321]  <TASK>
[ 15.315663][ T321] dump_stack_lvl (lib/dump_stack.c:123)
[ 15.315816][ T321] print_deadlock_bug (kernel/locking/lockdep.c:3040)
[ 15.315968][ T321] validate_chain (kernel/locking/lockdep.c:3894)
[ 15.316122][ T321] ? __pfx_validate_chain (kernel/locking/lockdep.c:3860)
[ 15.316273][ T321] ? 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)
[ 15.316420][ T321] ? mark_lock (kernel/locking/lockdep.c:4727 (discriminator 3))
[ 15.316536][ T321] __lock_acquire (kernel/locking/lockdep.c:5226)
[ 15.316699][ T321] lock_acquire.part.0 (kernel/locking/lockdep.c:467 kernel/locking/lockdep.c:5851)
[ 15.316862][ T321] ? blocking_notifier_call_chain (kernel/notifier.c:380 kernel/notifier.c:368)
[ 15.317049][ T321] ? __pfx_lock_acquire.part.0 (kernel/locking/lockdep.c:5814)
[ 15.317203][ T321] ? trace_lock_acquire (./include/trace/events/lock.h:24 (discriminator 37))
[ 15.317353][ T321] ? lock_acquire (kernel/locking/lockdep.c:5822)
[ 15.317501][ T321] ? blocking_notifier_call_chain (kernel/notifier.c:380 kernel/notifier.c:368)
[ 15.317686][ T321] down_read (./arch/x86/include/asm/preempt.h:79 kernel/locking/rwsem.c:1246 kernel/locking/rwsem.c:1261 kernel/locking/rwsem.c:1526)
[ 15.317801][ T321] ? blocking_notifier_call_chain (kernel/notifier.c:380 kernel/notifier.c:368)
[ 15.317998][ T321] ? __pfx_down_read (kernel/locking/rwsem.c:1522)
[ 15.318151][ T321] blocking_notifier_call_chain (kernel/notifier.c:380 kernel/notifier.c:368)
[ 15.318298][ T321] netdev_update_features (net/core/dev.c:10314)
[ 15.318446][ T321] ? __pfx_netdev_update_features (net/core/dev.c:10311)
[ 15.318627][ T321] vlan_device_event (net/8021q/vlan.c:430 (discriminator 2))
[ 15.318779][ T321] ? __pfx_vlan_device_event (net/8021q/vlan.c:362)
[ 15.318925][ T321] ? __pfx_br_device_event (net/bridge/br.c:29)
[ 15.319074][ T321] ? packet_notifier (net/packet/af_packet.c:4282)
[ 15.319219][ T321] notifier_call_chain (kernel/notifier.c:85 (discriminator 2))
[ 15.319369][ T321] blocking_notifier_call_chain (kernel/notifier.c:381 kernel/notifier.c:368)
[ 15.319514][ T321] netdev_update_features (net/core/dev.c:10314)
[ 15.319662][ T321] ? __pfx_netdev_update_features (net/core/dev.c:10311)
[ 15.319841][ T321] br_add_if (net/bridge/br_if.c:657)
[ 15.319955][ T321] ? rtnl_is_locked (net/core/rtnetlink.c:163)
[ 15.320100][ T321] ? netdev_master_upper_dev_get (net/core/dev.c:7230)
[ 15.320280][ T321] do_setlink.constprop.0 (net/core/rtnetlink.c:3125)
[ 15.320425][ T321] ? __pfx_do_setlink.constprop.0 (net/core/rtnetlink.c:2999)
[ 15.320603][ T321] ? lock_acquire.part.0 (kernel/locking/lockdep.c:467 kernel/locking/lockdep.c:5851)
[ 15.320753][ T321] ? rtnl_newlink (net/core/rtnetlink.c:337 net/core/rtnetlink.c:4020)
[ 15.320900][ T321] ? rtnl_newlink (./include/linux/slab.h:901 net/core/rtnetlink.c:3921)
[ 15.321043][ T321] ? rtnetlink_rcv_msg (net/core/rtnetlink.c:6911)
[ 15.321188][ T321] ? __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)
[ 15.321337][ T321] ? __pfx___mutex_trylock_common (kernel/locking/mutex.c:79)
[ 15.321517][ T321] ? lock_acquire (kernel/locking/lockdep.c:5822)
[ 15.321661][ T321] ? trace_contention_end (./include/trace/events/lock.h:122 (discriminator 37))
[ 15.321810][ T321] ? __mutex_lock (./arch/x86/include/asm/preempt.h:94 kernel/locking/mutex.c:595 kernel/locking/mutex.c:735)
[ 15.321959][ T321] ? __pfx_do_raw_spin_lock (kernel/locking/spinlock_debug.c:114)
[ 15.322104][ T321] ? rtnl_newlink (net/core/rtnetlink.c:337 net/core/rtnetlink.c:4020)
[ 15.322248][ T321] ? __pfx___mutex_lock (kernel/locking/mutex.c:734)
[ 15.322394][ T321] ? __rtnl_newlink (net/core/rtnetlink.c:3871)
[ 15.322540][ T321] rtnl_newlink (net/core/rtnetlink.c:345 net/core/rtnetlink.c:4022)
[ 15.322684][ T321] ? __pfx_rtnl_newlink (net/core/rtnetlink.c:3912)
[ 15.322831][ T321] ? find_held_lock (kernel/locking/lockdep.c:5339)
[ 15.322980][ T321] ? __pfx___lock_release (kernel/locking/lockdep.c:5501)
[ 15.323126][ T321] ? __pfx_lock_acquire.part.0 (kernel/locking/lockdep.c:5814)
[ 15.323273][ T321] ? rtnetlink_rcv_msg (./include/linux/rcupdate.h:347 ./include/linux/rcupdate.h:880 net/core/rtnetlink.c:6909)
[ 15.323417][ T321] ? __pfx_rtnl_newlink (net/core/rtnetlink.c:3912)
[ 15.323561][ T321] rtnetlink_rcv_msg (net/core/rtnetlink.c:6911)
[ 15.323706][ T321] ? __pfx_rtnetlink_rcv_msg (net/core/rtnetlink.c:6814)
[ 15.323853][ T321] ? 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)
[ 15.324019][ T321] ? mark_lock (kernel/locking/lockdep.c:4727 (discriminator 3))
[ 15.324132][ T321] ? __lock_acquire (kernel/locking/lockdep.c:5226)
[ 15.324282][ T321] netlink_rcv_skb (net/netlink/af_netlink.c:2543)
[ 15.324431][ T321] ? __pfx_rtnetlink_rcv_msg (net/core/rtnetlink.c:6814)
[ 15.324579][ T321] ? __pfx_netlink_rcv_skb (net/netlink/af_netlink.c:2520)
[ 15.324734][ T321] ? netlink_deliver_tap (./include/linux/rcupdate.h:347 ./include/linux/rcupdate.h:880 net/netlink/af_netlink.c:340)
[ 15.324885][ T321] ? 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)
[ 15.325036][ T321] netlink_unicast (net/netlink/af_netlink.c:1322 net/netlink/af_netlink.c:1348)
[ 15.325195][ T321] ? __pfx_netlink_unicast (net/netlink/af_netlink.c:1333)
[ 15.325339][ T321] ? find_held_lock (kernel/locking/lockdep.c:5339)
[ 15.325491][ T321] netlink_sendmsg (net/netlink/af_netlink.c:1892)
[ 15.325659][ T321] ? __pfx_netlink_sendmsg (net/netlink/af_netlink.c:1811)
[ 15.325812][ T321] ____sys_sendmsg (net/socket.c:711 net/socket.c:726 net/socket.c:2594)
[ 15.325962][ T321] ? __pfx_____sys_sendmsg (net/socket.c:2540)
[ 15.326114][ T321] ? __pfx_copy_msghdr_from_user (net/socket.c:2520)
[ 15.326302][ T321] ___sys_sendmsg (net/socket.c:2650)
[ 15.326450][ T321] ? __pfx____sys_sendmsg (net/socket.c:2637)
[ 15.326601][ T321] ? kasan_save_stack (mm/kasan/common.c:49)
[ 15.326766][ T321] ? kasan_save_stack (mm/kasan/common.c:48)
[ 15.326913][ T321] ? __kasan_record_aux_stack (mm/kasan/generic.c:544)
[ 15.327058][ T321] ? __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)
[ 15.327245][ T321] ? __x64_sys_close (fs/open.c:1557 fs/open.c:1539 fs/open.c:1539)
[ 15.327391][ T321] ? do_syscall_64 (arch/x86/entry/common.c:52 arch/x86/entry/common.c:83)
[ 15.327542][ T321] ? entry_SYSCALL_64_after_hwframe (arch/x86/entry/entry_64.S:130)
[ 15.327725][ T321] ? __lock_acquire (kernel/locking/lockdep.c:5226)
[ 15.327872][ T321] ? find_held_lock (kernel/locking/lockdep.c:5339)
[ 15.328017][ T321] ? __lock_release (kernel/locking/lockdep.c:5525)
[ 15.328160][ T321] ? __virt_addr_valid (./include/linux/rcupdate.h:347 ./include/linux/rcupdate.h:962 ./include/linux/mmzone.h:2058 arch/x86/mm/physaddr.c:65)
[ 15.328306][ T321] ? __pfx___lock_release (kernel/locking/lockdep.c:5501)
[ 15.328455][ T321] ? __pfx_lock_acquire.part.0 (kernel/locking/lockdep.c:5814)
[ 15.328601][ T321] __sys_sendmsg (net/socket.c:2680)
[ 15.328747][ T321] ? __pfx___sys_sendmsg (net/socket.c:2665)
[ 15.328890][ T321] ? __pfx_slab_free_after_rcu_debug (mm/slub.c:4643)
[ 15.329076][ T321] do_syscall_64 (arch/x86/entry/common.c:52 arch/x86/entry/common.c:83)
[ 15.329220][ T321] entry_SYSCALL_64_after_hwframe (arch/x86/entry/entry_64.S:130)
[   15.329416][  T321] RIP: 0033:0x7f24abfff9a7
[ 15.329573][ T321] 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)
[   15.330109][  T321] RSP: 002b:00007ffc9c2abfb8 EFLAGS: 00000246 ORIG_RAX: 000000000000002e
[   15.330334][  T321] RAX: ffffffffffffffda RBX: 00007ffc9c2ac6f0 RCX: 00007f24abfff9a7
[   15.330558][  T321] RDX: 0000000000000000 RSI: 00007ffc9c2ac020 RDI: 0000000000000005
[   15.330782][  T321] RBP: 0000000000000005 R08: 0000000000000003 R09: 0000000000000000
[   15.331004][  T321] R10: 000000001cd98910 R11: 0000000000000246 R12: 0000000000000005


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