------------[ cut here ]------------
WARNING: CPU: 3 PID: 67 at net/l2tp/l2tp_core.c:1879 l2tp_exit_net+0xab/0x1a0 net/l2tp/l2tp_core.c:1879
Modules linked in:
CPU: 3 UID: 0 PID: 67 Comm: kworker/u32:3 Not tainted 6.12.0-rc3-syzkaller-00420-g715ca9dd687f #0
Hardware name: QEMU Standard PC (Q35 + ICH9, 2009), BIOS 1.16.3-debian-1.16.3-2~bpo12+1 04/01/2014
Workqueue: netns cleanup_net
RIP: 0010:l2tp_exit_net+0xab/0x1a0 net/l2tp/l2tp_core.c:1879
Code: ab 30 01 00 00 48 89 fa 48 c1 ea 03 80 3c 02 00 0f 85 f1 00 00 00 48 83 bb 78 01 00 00 00 0f 84 89 00 00 00 e8 06 a7 42 f7 90 <0f> 0b 90 e8 fd a6 42 f7 48 89 ef e8 55 93 c7 00 48 8d bb 88 00 00
RSP: 0018:ffffc90000d47b98 EFLAGS: 00010293
RAX: 0000000000000000 RBX: ffff88804a884800 RCX: ffffffff8b127015
RDX: ffff888020c02440 RSI: ffffffff8a4adc5a RDI: ffff88804a884978
RBP: ffff88804a884930 R08: 0000000000000007 R09: 0000000000000002
R10: 0000000000000000 R11: 0000000000000000 R12: 0000000004000000
R13: ffffc90000d47c30 R14: dffffc0000000000 R15: fffffbfff2041610
FS:  0000000000000000(0000) GS:ffff88806a900000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 00007f932190a338 CR3: 0000000042140000 CR4: 0000000000352ef0
DR0: 0000000000000000 DR1: 0000000000000040 DR2: 0000000000000000
DR3: 0000000000000000 DR6: 00000000ffff0ff0 DR7: 0000000000000400
Call Trace:
 <TASK>
 ops_exit_list+0xb0/0x180 net/core/net_namespace.c:173
 cleanup_net+0x5b7/0xb40 net/core/net_namespace.c:626
 process_one_work+0x9c5/0x1ba0 kernel/workqueue.c:3229
 process_scheduled_works kernel/workqueue.c:3310 [inline]
 worker_thread+0x6c8/0xf00 kernel/workqueue.c:3391
 kthread+0x2c1/0x3a0 kernel/kthread.c:389
 ret_from_fork+0x45/0x80 arch/x86/kernel/process.c:147
 ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:244
 </TASK>