======================================
| [ 46.015633][ T980] #0: ffffffff9cfe3948 (rtnl_mutex){+.+.}-{4:4}, at: rtnl_newlink (net/core/rtnetlink.c:328 net/core/rtnetlink.c:4011)
| [ 46.015929][ T980] #1: ffffffff9cfd25f0 ((netdev_chain).rwsem){++++}-{4:4}, at: blocking_notifier_call_chain (kernel/notifier.c:380 kernel/notifier.c:368)
| [   46.016281][  T980]
| [   46.016281][  T980] stack backtrace:
[   46.016783][  T980] Hardware name: Bochs Bochs, BIOS Bochs 01/01/2011
[   46.017017][  T980] Call Trace:
[   46.017146][  T980]  <TASK>
[ 46.017234][ T980] dump_stack_lvl (lib/dump_stack.c:123)
[ 46.017419][ T980] print_deadlock_bug (kernel/locking/lockdep.c:3040)
[ 46.017619][ T980] validate_chain (kernel/locking/lockdep.c:3894)
[ 46.017813][ T980] ? __pfx_validate_chain (kernel/locking/lockdep.c:3860)
[ 46.018020][ T980] ? 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)
[ 46.018226][ T980] ? mark_lock (kernel/locking/lockdep.c:4727 (discriminator 3))
[ 46.018381][ T980] __lock_acquire (kernel/locking/lockdep.c:5226)
[ 46.018584][ T980] ? 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)
[ 46.018788][ T980] lock_acquire.part.0 (kernel/locking/lockdep.c:467 kernel/locking/lockdep.c:5851)
[ 46.019001][ T980] ? blocking_notifier_call_chain (kernel/notifier.c:380 kernel/notifier.c:368)
[ 46.019259][ T980] ? 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)
[ 46.019463][ T980] ? __pfx_lock_acquire.part.0 (kernel/locking/lockdep.c:5814)
[ 46.019670][ T980] ? trace_lock_acquire (./include/trace/events/lock.h:24 (discriminator 37))
[ 46.019884][ T980] ? lock_acquire (kernel/locking/lockdep.c:5822)
[ 46.020085][ T980] ? blocking_notifier_call_chain (kernel/notifier.c:380 kernel/notifier.c:368)
[ 46.020328][ T980] down_read (./arch/x86/include/asm/preempt.h:79 kernel/locking/rwsem.c:1246 kernel/locking/rwsem.c:1261 kernel/locking/rwsem.c:1526)
[ 46.020481][ T980] ? blocking_notifier_call_chain (kernel/notifier.c:380 kernel/notifier.c:368)
[ 46.020725][ T980] ? __pfx_down_read (kernel/locking/rwsem.c:1522)
[ 46.020908][ T980] ? notifier_call_chain (kernel/notifier.c:85 (discriminator 2))
[ 46.021096][ T980] blocking_notifier_call_chain (kernel/notifier.c:380 kernel/notifier.c:368)
[ 46.021290][ T980] call_netdevice_notifiers (net/core/dev.c:2062)
[ 46.021488][ T980] ? __pfx_call_netdevice_notifiers (net/core/dev.c:2062)
[ 46.021753][ T980] ? 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)
[ 46.021947][ T980] udp_tunnel_nic_netdevice_event (net/ipv4/udp_tunnel_nic.c:915) udp_tunnel
[ 46.022257][ T980] notifier_call_chain (kernel/notifier.c:85 (discriminator 2))
[ 46.022444][ T980] blocking_notifier_call_chain (kernel/notifier.c:381 kernel/notifier.c:368)
[ 46.022644][ T980] __dev_notify_flags (net/core/dev.c:9010)
[ 46.022814][ T980] ? __pfx___dev_notify_flags (net/core/dev.c:8997)
[ 46.022992][ T980] ? __pfx___dev_change_flags (net/core/dev.c:8930)
[ 46.023184][ T980] ? unwind_get_return_address (arch/x86/kernel/unwind_orc.c:369 arch/x86/kernel/unwind_orc.c:364)
[ 46.023384][ T980] ? __pfx_stack_trace_consume_entry (kernel/stacktrace.c:83)
[ 46.023636][ T980] ? __pfx_validate_chain (kernel/locking/lockdep.c:3860)
[ 46.023822][ T980] dev_change_flags (net/core/dev.c:9045)
[ 46.024021][ T980] do_setlink.constprop.0 (net/core/rtnetlink.c:3109)
[ 46.024207][ T980] ? __pfx_do_setlink.constprop.0 (net/core/rtnetlink.c:2990)
[ 46.024461][ T980] ? lock_acquire.part.0 (kernel/locking/lockdep.c:467 kernel/locking/lockdep.c:5851)
[ 46.024661][ T980] ? rtnl_newlink (net/core/rtnetlink.c:328 net/core/rtnetlink.c:4011)
[ 46.024850][ T980] ? rtnl_newlink (./include/linux/slab.h:901 net/core/rtnetlink.c:3912)
[ 46.025043][ T980] ? rtnetlink_rcv_msg (net/core/rtnetlink.c:6902)
[ 46.025238][ T980] ? __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)
[ 46.025450][ T980] ? __pfx___mutex_trylock_common (kernel/locking/mutex.c:79)
[ 46.025708][ T980] ? lock_acquire (kernel/locking/lockdep.c:5822)
[ 46.025911][ T980] ? trace_contention_end (./include/trace/events/lock.h:122 (discriminator 37))
[ 46.026110][ T980] ? __mutex_lock (./arch/x86/include/asm/preempt.h:94 kernel/locking/mutex.c:595 kernel/locking/mutex.c:735)
[ 46.026294][ T980] ? __pfx_do_raw_spin_lock (kernel/locking/spinlock_debug.c:114)
[ 46.026479][ T980] ? rtnl_newlink (net/core/rtnetlink.c:328 net/core/rtnetlink.c:4011)
[ 46.026655][ T980] ? __pfx___mutex_lock (kernel/locking/mutex.c:734)
[ 46.026836][ T980] ? __create_object (mm/kmemleak.c:766)
[ 46.027016][ T980] ? __rtnl_newlink (net/core/rtnetlink.c:3862)
[ 46.027197][ T980] rtnl_newlink (net/core/rtnetlink.c:336 net/core/rtnetlink.c:4013)
[ 46.027391][ T980] ? __pfx_rtnl_newlink (net/core/rtnetlink.c:3903)
[ 46.027574][ T980] ? find_held_lock (kernel/locking/lockdep.c:5339)
[ 46.027744][ T980] ? __pfx___lock_release (kernel/locking/lockdep.c:5501)
[ 46.027923][ T980] ? __pfx_lock_acquire.part.0 (kernel/locking/lockdep.c:5814)
[ 46.028107][ T980] ? rtnetlink_rcv_msg (./include/linux/rcupdate.h:347 ./include/linux/rcupdate.h:880 net/core/rtnetlink.c:6900)
[ 46.028275][ T980] ? __pfx_rtnl_newlink (net/core/rtnetlink.c:3903)
[ 46.028447][ T980] rtnetlink_rcv_msg (net/core/rtnetlink.c:6902)
[ 46.028651][ T980] ? __pfx_rtnetlink_rcv_msg (net/core/rtnetlink.c:6805)
[ 46.028855][ T980] ? 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)
[ 46.029047][ T980] ? mark_lock (kernel/locking/lockdep.c:4727 (discriminator 3))
[ 46.029176][ T980] ? __lock_acquire (kernel/locking/lockdep.c:5226)
[ 46.029347][ T980] netlink_rcv_skb (net/netlink/af_netlink.c:2543)
[ 46.029515][ T980] ? __pfx_rtnetlink_rcv_msg (net/core/rtnetlink.c:6805)
[ 46.029680][ T980] ? __pfx_netlink_rcv_skb (net/netlink/af_netlink.c:2520)
[ 46.029861][ T980] ? netlink_deliver_tap (./include/linux/rcupdate.h:347 ./include/linux/rcupdate.h:880 net/netlink/af_netlink.c:340)
[ 46.030036][ T980] ? 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)
[ 46.030204][ T980] netlink_unicast (net/netlink/af_netlink.c:1322 net/netlink/af_netlink.c:1348)
[ 46.030370][ T980] ? __pfx_netlink_unicast (net/netlink/af_netlink.c:1333)
[ 46.030536][ T980] ? find_held_lock (kernel/locking/lockdep.c:5339)
[ 46.030703][ T980] netlink_sendmsg (net/netlink/af_netlink.c:1892)
[ 46.030867][ T980] ? __pfx_netlink_sendmsg (net/netlink/af_netlink.c:1811)
[ 46.031083][ T980] ____sys_sendmsg (net/socket.c:711 net/socket.c:726 net/socket.c:2594)
[ 46.031259][ T980] ? __pfx_____sys_sendmsg (net/socket.c:2540)
[ 46.031436][ T980] ? __pfx_copy_msghdr_from_user (net/socket.c:2520)
[ 46.031680][ T980] ___sys_sendmsg (net/socket.c:2650)
[ 46.031879][ T980] ? __pfx____sys_sendmsg (net/socket.c:2637)
[ 46.032048][ T980] ? kasan_save_stack (mm/kasan/common.c:49)
[ 46.032216][ T980] ? kasan_save_stack (mm/kasan/common.c:48)
[ 46.032382][ T980] ? __kasan_record_aux_stack (mm/kasan/generic.c:544)
[ 46.032564][ T980] ? __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)
[ 46.032782][ T980] ? __x64_sys_close (fs/open.c:1557 fs/open.c:1539 fs/open.c:1539)
[ 46.032966][ T980] ? do_syscall_64 (arch/x86/entry/common.c:52 arch/x86/entry/common.c:83)
[ 46.033164][ T980] ? entry_SYSCALL_64_after_hwframe (arch/x86/entry/entry_64.S:130)
[ 46.033398][ T980] ? __lock_acquire (kernel/locking/lockdep.c:5226)
[ 46.033592][ T980] ? find_held_lock (kernel/locking/lockdep.c:5339)
[ 46.033794][ T980] ? __lock_release (kernel/locking/lockdep.c:5525)
[ 46.034004][ T980] ? __virt_addr_valid (./include/linux/rcupdate.h:347 ./include/linux/rcupdate.h:962 ./include/linux/mmzone.h:2058 arch/x86/mm/physaddr.c:65)
[ 46.034228][ T980] ? __pfx___lock_release (kernel/locking/lockdep.c:5501)
[ 46.034438][ T980] ? __pfx_lock_acquire.part.0 (kernel/locking/lockdep.c:5814)
[ 46.034650][ T980] __sys_sendmsg (net/socket.c:2680)
[ 46.034852][ T980] ? __pfx___sys_sendmsg (net/socket.c:2665)
[ 46.035048][ T980] ? __pfx_slab_free_after_rcu_debug (mm/slub.c:4643)
[ 46.035310][ T980] do_syscall_64 (arch/x86/entry/common.c:52 arch/x86/entry/common.c:83)
[ 46.035516][ T980] entry_SYSCALL_64_after_hwframe (arch/x86/entry/entry_64.S:130)
[   46.035761][  T980] RIP: 0033:0x7fd66ee189a7
[ 46.035964][ T980] 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)
[   46.036625][  T980] RSP: 002b:00007ffe5dd70dc8 EFLAGS: 00000246 ORIG_RAX: 000000000000002e
[   46.036913][  T980] RAX: ffffffffffffffda RBX: 00007ffe5dd714f0 RCX: 00007fd66ee189a7
[   46.037203][  T980] RDX: 0000000000000000 RSI: 00007ffe5dd70e30 RDI: 0000000000000005
[   46.037487][  T980] RBP: 0000000000000003 R08: 0000000000000003 R09: 0000000000000078
[   46.037785][  T980] R10: 00007fd66ecd6ef8 R11: 0000000000000246 R12: 0000000000000003


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