------------[ cut here ]------------ ODEBUG: free active (active state 0) object: ffff88807f98b000 object type: work_struct hint: udp_tunnel_nic_device_sync_work+0x0/0xa50 net/ipv4/udp_tunnel_nic.c:-1 WARNING: CPU: 0 PID: 21506 at lib/debugobjects.c:615 debug_print_object+0x16b/0x1e0 lib/debugobjects.c:612 Modules linked in: CPU: 0 UID: 0 PID: 21506 Comm: syz.3.4222 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+0x16b/0x1e0 lib/debugobjects.c:612 Code: 4c 89 ff e8 97 26 95 fd 4d 8b 0f 48 c7 c7 80 ce 9e 8b 48 8b 34 24 4c 89 ea 89 e9 4d 89 f0 41 54 e8 8a ea f3 fc 48 83 c4 08 90 <0f> 0b 90 90 ff 05 67 bd cd 0a 48 83 c4 08 5b 41 5c 41 5d 41 5e 41 RSP: 0018:ffffc9000c4b6558 EFLAGS: 00010282 RAX: 4e5494f273183d00 RBX: dffffc0000000000 RCX: 0000000000080000 RDX: ffffc90018131000 RSI: 00000000000082e8 RDI: 00000000000082e9 RBP: 0000000000000000 R08: 0000000000000003 R09: 0000000000000004 R10: dffffc0000000000 R11: fffffbfff1b7a118 R12: ffffffff89d361d0 R13: ffffffff8b9ed000 R14: ffff88807f98b000 R15: ffffffff8b49cc00 FS: 00007f38093f96c0(0000) GS:ffff88812639b000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 00007f00775156c0 CR3: 000000001cad0000 CR4: 00000000003526f0 Call Trace: __debug_check_no_obj_freed lib/debugobjects.c:1099 [inline] debug_check_no_obj_freed+0x3a2/0x470 lib/debugobjects.c:1129 slab_free_hook mm/slub.c:2353 [inline] slab_free mm/slub.c:4695 [inline] kfree+0x112/0x440 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+0x11ab/0x1810 net/ipv4/udp_tunnel_nic.c:942 notifier_call_chain+0x1b6/0x3e0 kernel/notifier.c:85 call_netdevice_notifiers_extack net/core/dev.c:2267 [inline] call_netdevice_notifiers net/core/dev.c:2281 [inline] __dev_change_net_namespace+0xd33/0x2030 net/core/dev.c:12450 do_setlink+0x292/0x41c0 net/core/rtnetlink.c:3053 rtnl_changelink net/core/rtnetlink.c:3769 [inline] __rtnl_newlink net/core/rtnetlink.c:3928 [inline] rtnl_newlink+0x1619/0x1c80 net/core/rtnetlink.c:4065 rtnetlink_rcv_msg+0x7cc/0xb70 net/core/rtnetlink.c:6954 netlink_rcv_skb+0x205/0x470 net/netlink/af_netlink.c:2552 netlink_unicast_kernel net/netlink/af_netlink.c:1320 [inline] netlink_unicast+0x82c/0x9e0 net/netlink/af_netlink.c:1346 netlink_sendmsg+0x805/0xb30 net/netlink/af_netlink.c:1896 sock_sendmsg_nosec net/socket.c:727 [inline] __sock_sendmsg+0x219/0x270 net/socket.c:742 ____sys_sendmsg+0x505/0x830 net/socket.c:2630 ___sys_sendmsg+0x21f/0x2a0 net/socket.c:2684 __sys_sendmsg net/socket.c:2716 [inline] __do_sys_sendmsg net/socket.c:2721 [inline] __se_sys_sendmsg net/socket.c:2719 [inline] __x64_sys_sendmsg+0x19b/0x260 net/socket.c:2719 do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline] do_syscall_64+0xfa/0x3b0 arch/x86/entry/syscall_64.c:94 entry_SYSCALL_64_after_hwframe+0x77/0x7f RIP: 0033:0x7f380858eec9 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:00007f38093f9038 EFLAGS: 00000246 ORIG_RAX: 000000000000002e RAX: ffffffffffffffda RBX: 00007f38087e6090 RCX: 00007f380858eec9 RDX: 0000000000000000 RSI: 0000200000000280 RDI: 0000000000000004 RBP: 00007f3808611f91 R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000 R13: 00007f38087e6128 R14: 00007f38087e6090 R15: 00007ffd4e6e3ca8