syzbot

netdevsim netdevsim0 netdevsim0 (unregistering): unset [1, 0] type 2 family 0 port 6081 - 0
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ODEBUG: free active (active state 0) object: ffff88807813ac00 object type: work_struct hint: udp_tunnel_nic_device_sync_work+0x0/0xa10 net/ipv4/udp_tunnel_nic.c:912
WARNING: CPU: 1 PID: 11537 at lib/debugobjects.c:612 debug_print_object+0x1a2/0x2b0 lib/debugobjects.c:612
Modules linked in:
CPU: 1 UID: 0 PID: 11537 Comm: syz.1.439 Not tainted syzkaller #0 PREEMPT(full) 
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 08/18/2025
RIP: 0010:debug_print_object+0x1a2/0x2b0 lib/debugobjects.c:612
Code: fc ff df 48 89 fa 48 c1 ea 03 80 3c 02 00 75 54 41 56 48 8b 14 dd a0 1e d0 8b 4c 89 e6 48 c7 c7 20 13 d0 8b e8 ff b1 d5 fc 90 <0f> 0b 90 90 58 83 05 a6 22 bd 0b 01 48 83 c4 18 5b 5d 41 5c 41 5d
RSP: 0000:ffffc90003707638 EFLAGS: 00010286
RAX: 0000000000000000 RBX: 0000000000000003 RCX: ffffc9000c242000
RDX: 0000000000080000 RSI: ffffffff81796535 RDI: 0000000000000001
RBP: 0000000000000001 R08: 0000000000000001 R09: 0000000000000000
R10: 0000000000000001 R11: fffffffffffdd098 R12: ffffffff8bd019c0
R13: ffffffff8b6c1a20 R14: ffffffff89dc1110 R15: ffffc90003707738
FS:  00007f58517a06c0(0000) GS:ffff888124f66000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 00007f3174f0a4e8 CR3: 000000005ef7c000 CR4: 00000000003526f0
Call Trace:
 <TASK>
 __debug_check_no_obj_freed lib/debugobjects.c:1099 [inline]
 debug_check_no_obj_freed+0x4b7/0x600 lib/debugobjects.c:1129
 slab_free_hook mm/slub.c:2353 [inline]
 slab_free mm/slub.c:4695 [inline]
 kfree+0x28f/0x4d0 mm/slub.c:4894
 udp_tunnel_nic_free net/ipv4/udp_tunnel_nic.c:785 [inline]
 udp_tunnel_nic_unregister net/ipv4/udp_tunnel_nic.c:910 [inline]
 udp_tunnel_nic_netdevice_event+0xd2a/0x1fa0 net/ipv4/udp_tunnel_nic.c:942
 notifier_call_chain+0xbc/0x410 kernel/notifier.c:85
 call_netdevice_notifiers_info+0xbe/0x140 net/core/dev.c:2229
 call_netdevice_notifiers_extack net/core/dev.c:2267 [inline]
 call_netdevice_notifiers net/core/dev.c:2281 [inline]
 unregister_netdevice_many_notify+0xf76/0x24c0 net/core/dev.c:12166
 unregister_netdevice_many net/core/dev.c:12229 [inline]
 unregister_netdevice_queue+0x305/0x3f0 net/core/dev.c:12073
 unregister_netdevice include/linux/netdevice.h:3385 [inline]
 nsim_destroy+0x198/0x800 drivers/net/netdevsim/netdev.c:1140
 __nsim_dev_port_del+0x189/0x240 drivers/net/netdevsim/dev.c:1473
 nsim_drv_port_del+0x118/0x180 drivers/net/netdevsim/dev.c:1777
 del_port_store+0x129/0x170 drivers/net/netdevsim/bus.c:118
 dev_attr_store+0x55/0x80 drivers/base/core.c:2437
 sysfs_kf_write+0xef/0x150 fs/sysfs/file.c:142
 kernfs_fop_write_iter+0x3ac/0x570 fs/kernfs/file.c:352
 new_sync_write fs/read_write.c:593 [inline]
 vfs_write+0x7d0/0x11d0 fs/read_write.c:686
 ksys_write+0x12a/0x250 fs/read_write.c:738
 do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline]
 do_syscall_64+0xcd/0x4b0 arch/x86/entry/syscall_64.c:94
 entry_SYSCALL_64_after_hwframe+0x77/0x7f
RIP: 0033:0x7f585098eec9
Code: ff ff c3 66 2e 0f 1f 84 00 00 00 00 00 0f 1f 40 00 48 89 f8 48 89 f7 48 89 d6 48 89 ca 4d 89 c2 4d 89 c8 4c 8b 4c 24 08 0f 05 <48> 3d 01 f0 ff ff 73 01 c3 48 c7 c1 a8 ff ff ff f7 d8 64 89 01 48
RSP: 002b:00007f58517a0038 EFLAGS: 00000246 ORIG_RAX: 0000000000000001
RAX: ffffffffffffffda RBX: 00007f5850be6180 RCX: 00007f585098eec9
RDX: 0000000000000001 RSI: 0000200000000380 RDI: 000000000000000b
RBP: 00007f5850a11f91 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000
R13: 00007f5850be6218 R14: 00007f5850be6180 R15: 00007ffec38dd718
 </TASK>