======================================
| [   16.478737][  T281] veth1: entered promiscuous mode
| [   16.480871][  T281] ------------[ cut here ]------------
| [ 16.481224][ T281] WARNING: CPU: 2 PID: 281 at ./include/net/netdev_lock.h:17 netif_set_mtu_ext (./include/net/netdev_lock.h:17 ./include/net/netdev_lock.h:15 ./include/net/netdev_lock.h:25 net/core/dev.c:9610) 
| [   16.481862][  T281] Modules linked in: bridge stp llc vrf veth
[   16.482918][  T281] Hardware name: Bochs Bochs, BIOS Bochs 01/01/2011
[ 16.483334][ T281] RIP: 0010:netif_set_mtu_ext (./include/net/netdev_lock.h:17 ./include/net/netdev_lock.h:15 ./include/net/netdev_lock.h:25 net/core/dev.c:9610) 
[ 16.483669][ T281] Code: 00 00 8b 05 b7 bb 3a 02 85 c0 0f 84 52 fe ff ff 48 8d bb a0 0c 00 00 be ff ff ff ff e8 fa 61 7b 00 85 c0 0f 85 39 fe ff ff 90 <0f> 0b 90 e9 30 fe ff ff 48 b8 00 00 00 00 00 fc ff df 4c 89 fa 48
All code
========
   0:	00 00                	add    %al,(%rax)
   2:	8b 05 b7 bb 3a 02    	mov    0x23abbb7(%rip),%eax        # 0x23abbbf
   8:	85 c0                	test   %eax,%eax
   a:	0f 84 52 fe ff ff    	je     0xfffffffffffffe62
  10:	48 8d bb a0 0c 00 00 	lea    0xca0(%rbx),%rdi
  17:	be ff ff ff ff       	mov    $0xffffffff,%esi
  1c:	e8 fa 61 7b 00       	call   0x7b621b
  21:	85 c0                	test   %eax,%eax
  23:	0f 85 39 fe ff ff    	jne    0xfffffffffffffe62
  29:	90                   	nop
  2a:*	0f 0b                	ud2		<-- trapping instruction
  2c:	90                   	nop
  2d:	e9 30 fe ff ff       	jmp    0xfffffffffffffe62
  32:	48 b8 00 00 00 00 00 	movabs $0xdffffc0000000000,%rax
  39:	fc ff df 
  3c:	4c 89 fa             	mov    %r15,%rdx
  3f:	48                   	rex.W

Code starting with the faulting instruction
===========================================
   0:	0f 0b                	ud2
   2:	90                   	nop
   3:	e9 30 fe ff ff       	jmp    0xfffffffffffffe38
   8:	48 b8 00 00 00 00 00 	movabs $0xdffffc0000000000,%rax
   f:	fc ff df 
  12:	4c 89 fa             	mov    %r15,%rdx
  15:	48                   	rex.W
[   16.484956][  T281] RSP: 0018:ffffc90000696ef0 EFLAGS: 00010246
[   16.485371][  T281] RAX: 0000000000000000 RBX: ffff88800bbba000 RCX: 0000000000000001
[   16.485857][  T281] RDX: 0000000000000000 RSI: ffffffff9909b939 RDI: ffffffff988555e0
[   16.486343][  T281] RBP: ffffc90000696fe0 R08: 0000000000000000 R09: 0000000000000000
[   16.486834][  T281] R10: ffffc90000697010 R11: ffffffff99ea8918 R12: 1ffff920000d2de2
[   16.487325][  T281] R13: 00000000000005dc R14: ffffc90000697010 R15: ffff88800bbbaf08
[   16.487799][  T281] FS:  00007fb16d5be800(0000) GS:ffff88809b1b7000(0000) knlGS:0000000000000000
[   16.488360][  T281] CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
[   16.488765][  T281] CR2: 00000000004e5aa8 CR3: 0000000009683004 CR4: 0000000000772ef0
[   16.489259][  T281] PKRU: 55555554
[   16.489508][  T281] Call Trace:
[   16.489757][  T281]  <TASK>
[ 16.489933][ T281] ? __pfx_netif_set_mtu_ext (net/core/dev.c:9607) 
[ 16.490295][ T281] ? find_held_lock (kernel/locking/lockdep.c:5353) 
[ 16.490621][ T281] ? mark_held_locks (kernel/locking/lockdep.c:4328) 
[ 16.490942][ T281] ? _raw_spin_unlock_irqrestore (./include/linux/spinlock_api_smp.h:151 kernel/locking/spinlock.c:194) 
[ 16.491350][ T281] ? lockdep_hardirqs_on (kernel/locking/lockdep.c:4475) 
[ 16.491674][ T281] netif_set_mtu (net/core/dev.c:9652) 
[ 16.491997][ T281] ? __pfx_netif_set_mtu (net/core/dev.c:9647) 
[ 16.492340][ T281] ? br_get_link_af_size_filtered (net/bridge/br_netlink.c:116) bridge 
[ 16.492789][ T281] dev_set_mtu (./include/net/netdev_lock.h:30 ./include/net/netdev_lock.h:47 net/core/dev_api.c:249) 
[ 16.493034][ T281] br_mtu_auto_adjust (net/bridge/br_if.c:525) bridge 
[ 16.493479][ T281] br_add_if (net/bridge/br_if.c:697) bridge 
[ 16.493847][ T281] do_set_master (./include/net/netdev_lock.h:30 ./include/net/netdev_lock.h:41 net/core/rtnetlink.c:2949) 
[ 16.494174][ T281] do_setlink.constprop.0 (net/core/rtnetlink.c:3150) 
[ 16.494510][ T281] ? __pfx_do_setlink.constprop.0 (net/core/rtnetlink.c:3021) 
[ 16.494920][ T281] ? rcu_read_lock_any_held (kernel/rcu/update.c:386 kernel/rcu/update.c:380) 
[ 16.495250][ T281] ? validate_chain (kernel/locking/lockdep.c:3804 kernel/locking/lockdep.c:3824 kernel/locking/lockdep.c:3879) 
[ 16.495569][ T281] ? __kernel_text_address (kernel/extable.c:79) 
[ 16.495906][ T281] ? __lock_acquire (kernel/locking/lockdep.c:5240) 
[ 16.496247][ T281] ? __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:113) 
[ 16.496570][ T281] ? __pfx___mutex_trylock_common (kernel/locking/mutex.c:88) 
[ 16.496980][ T281] ? rcu_is_watching (./include/linux/context_tracking.h:128 kernel/rcu/tree.c:745) 
[ 16.497329][ T281] ? rcu_is_watching (./include/linux/context_tracking.h:128 kernel/rcu/tree.c:745) 
[ 16.497650][ T281] ? trace_contention_end (./include/trace/events/lock.h:122 (discriminator 21)) 
[ 16.497969][ T281] ? __mutex_lock (./arch/x86/include/asm/preempt.h:104 kernel/locking/mutex.c:728 kernel/locking/mutex.c:747) 
[ 16.498502][ T281] ? find_held_lock (kernel/locking/lockdep.c:5353) 
[ 16.498963][ T281] ? rtnl_newlink (net/core/rtnetlink.c:343 net/core/rtnetlink.c:4056) 
[ 16.499504][ T281] ? __create_object (mm/kmemleak.c:771) 
[ 16.499888][ T281] ? __pfx___mutex_lock (kernel/locking/mutex.c:746) 
[ 16.500221][ T281] ? trace_cap_capable (./include/trace/events/capability.h:26 (discriminator 21)) 
[ 16.500549][ T281] ? _raw_spin_unlock_irqrestore (./arch/x86/include/asm/preempt.h:104 ./include/linux/spinlock_api_smp.h:152 kernel/locking/spinlock.c:194) 
[ 16.500944][ T281] ? __rtnl_newlink (net/core/rtnetlink.c:3907) 
[ 16.501284][ T281] rtnl_newlink (net/core/rtnetlink.c:351 net/core/rtnetlink.c:4058) 
[ 16.501613][ T281] ? __pfx_rtnl_newlink (net/core/rtnetlink.c:3948) 
[ 16.501934][ T281] ? __lock_acquire (kernel/locking/lockdep.c:5240) 
[ 16.502271][ T281] ? find_held_lock (kernel/locking/lockdep.c:5353) 
[ 16.502600][ T281] ? rtnetlink_rcv_msg (./include/linux/rcupdate.h:341 ./include/linux/rcupdate.h:871 net/core/rtnetlink.c:6944) 
[ 16.502922][ T281] ? __lock_release (kernel/locking/lockdep.c:5539) 
[ 16.503254][ T281] ? __pfx_rtnl_newlink (net/core/rtnetlink.c:3948) 
[ 16.503575][ T281] rtnetlink_rcv_msg (net/core/rtnetlink.c:6946) 
[ 16.503896][ T281] ? __pfx_rtnetlink_rcv_msg (net/core/rtnetlink.c:6849) 
[ 16.504228][ T281] ? __lock_acquire (kernel/locking/lockdep.c:5240) 
[ 16.504556][ T281] netlink_rcv_skb (net/netlink/af_netlink.c:2551) 
[ 16.504876][ T281] ? __pfx_rtnetlink_rcv_msg (net/core/rtnetlink.c:6849) 
[ 16.505202][ T281] ? __pfx_netlink_rcv_skb (net/netlink/af_netlink.c:2528) 
[ 16.505546][ T281] ? netlink_deliver_tap (./include/linux/rcupdate.h:341 ./include/linux/rcupdate.h:871 net/netlink/af_netlink.c:340) 
[ 16.505878][ T281] ? netlink_deliver_tap (./include/linux/rcupdate.h:341 ./include/linux/rcupdate.h:871 ./include/net/netns/generic.h:48 net/netlink/af_netlink.c:333) 
[ 16.506202][ T281] netlink_unicast (net/netlink/af_netlink.c:1321 net/netlink/af_netlink.c:1346) 
[ 16.506538][ T281] ? __pfx_netlink_unicast (net/netlink/af_netlink.c:1331) 
[ 16.506858][ T281] ? __lock_acquire (kernel/locking/lockdep.c:5240) 
[ 16.507186][ T281] netlink_sendmsg (net/netlink/af_netlink.c:1896) 
[ 16.507527][ T281] ? __pfx_netlink_sendmsg (net/netlink/af_netlink.c:1815) 
[ 16.507851][ T281] ? __import_iovec (lib/iov_iter.c:1441 lib/iov_iter.c:1456) 
[ 16.508178][ T281] ____sys_sendmsg (net/socket.c:714 net/socket.c:729 net/socket.c:2614) 
[ 16.508515][ T281] ? __pfx_____sys_sendmsg (net/socket.c:2560) 
[ 16.508841][ T281] ? __pfx_copy_msghdr_from_user (net/socket.c:2540) 
[ 16.509275][ T281] ___sys_sendmsg (net/socket.c:2670) 
[ 16.509595][ T281] ? kasan_record_aux_stack (mm/kasan/generic.c:548) 
[ 16.509920][ T281] ? __call_rcu_common.constprop.0 (./arch/x86/include/asm/irqflags.h:26 ./arch/x86/include/asm/irqflags.h:109 ./arch/x86/include/asm/irqflags.h:127 kernel/rcu/tree.c:3096) 
[ 16.510327][ T281] ? __pfx____sys_sendmsg (net/socket.c:2657) 
[ 16.510653][ T281] ? find_held_lock (kernel/locking/lockdep.c:5353) 
[ 16.510989][ T281] ? __lock_acquire (kernel/locking/lockdep.c:5240) 
[ 16.511331][ T281] ? find_held_lock (kernel/locking/lockdep.c:5353) 
[ 16.511651][ T281] ? __virt_addr_valid (./include/linux/rcupdate.h:341 ./include/linux/rcupdate.h:953 ./include/linux/mmzone.h:2168 arch/x86/mm/physaddr.c:65) 
[ 16.511968][ T281] ? __lock_release (kernel/locking/lockdep.c:5539) 
[ 16.512311][ T281] __sys_sendmsg (net/socket.c:2700) 
[ 16.512634][ T281] ? __call_rcu_common.constprop.0 (kernel/rcu/tree.c:3119) 
[ 16.513026][ T281] ? __pfx___sys_sendmsg (net/socket.c:2685) 
[ 16.513372][ T281] ? rcu_is_watching (./include/linux/context_tracking.h:128 kernel/rcu/tree.c:745) 
[ 16.513696][ T281] do_syscall_64 (arch/x86/entry/syscall_64.c:63 arch/x86/entry/syscall_64.c:94) 
[ 16.514017][ T281] entry_SYSCALL_64_after_hwframe (arch/x86/entry/entry_64.S:130) 
[   16.514420][  T281] RIP: 0033:0x7fb16d78b1e7
[ 16.514759][ T281] Code: 0e 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:	0e                   	(bad)
   1:	00 f7                	add    %dh,%bh
   3:	d8 64 89 02          	fsubs  0x2(%rcx,%rcx,4)
   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)
[   16.515894][  T281] RSP: 002b:00007fff006593d8 EFLAGS: 00000246 ORIG_RAX: 000000000000002e
[   16.516400][  T281] RAX: ffffffffffffffda RBX: 00007fff00659b00 RCX: 00007fb16d78b1e7
[   16.516885][  T281] RDX: 0000000000000000 RSI: 00007fff00659440 RDI: 0000000000000005
[   16.517635][  T281] RBP: 0000000000000004 R08: 0000000000000003 R09: 0000000000000000
[   16.518348][  T281] R10: 000000003ca0d910 R11: 0000000000000246 R12: 0000000000000004


Finger prints:
netif_set_mtu_ext:netif_set_mtu:dev_set_mtu:br_mtu_auto_adjust:br_add_if