___sys_sendmsg+0x110/0x1b0 net/socket.c:2530
 __sys_sendmmsg+0x1b7/0x540 net/socket.c:2616
 __do_sys_sendmmsg net/socket.c:2645 [inline]
 __se_sys_sendmmsg net/socket.c:2642 [inline]
 __x64_sys_sendmmsg+0x9d/0x100 net/socket.c:2642
 do_syscall_x64 arch/x86/entry/common.c:50 [inline]
 do_syscall_64+0x39/0xb0 arch/x86/entry/common.c:80
 entry_SYSCALL_64_after_hwframe+0x63/0xcd
------------[ cut here ]------------
WARNING: CPU: 1 PID: 9 at lib/ref_tracker.c:39 spin_unlock_irqrestore include/linux/spinlock.h:405 [inline]
WARNING: CPU: 1 PID: 9 at lib/ref_tracker.c:39 ref_tracker_dir_exit.cold+0x137/0x1e3 lib/ref_tracker.c:38
Modules linked in:
CPU: 1 PID: 9 Comm: kworker/u4:0 Not tainted 6.1.0-next-20221219-syzkaller #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 10/26/2022
Workqueue: netns cleanup_net
RIP: 0010:ref_tracker_dir_exit.cold+0x137/0x1e3 lib/ref_tracker.c:39
Code: 4c 89 ef e8 86 ac fc f7 4c 8b 3c 24 4c 39 fd 49 8b 07 0f 85 b5 00 00 00 e8 e1 8c ae f7 48 8b 74 24 10 4c 89 e7 e8 34 17 38 00 <0f> 0b e9 b6 38 67 fa 4c 89 ff e8 55 ac fc f7 e9 d4 fe ff ff e8 2b
RSP: 0018:ffffc900000e7c00 EFLAGS: 00010246
RAX: 0000000000000000 RBX: dffffc0000000000 RCX: 0000000000000000
RDX: 0000000000000001 RSI: 0000000000000001 RDI: 0000000000000001
RBP: ffff888077123b90 R08: 0000000000000001 R09: ffffffff91340bd7
R10: 0000000000000001 R11: 0000000000094001 R12: ffff888077123b40
R13: ffff888077123b90 R14: ffff888077123b90 R15: ffff888077123b90
FS:  0000000000000000(0000) GS:ffff8880b9900000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 00007f00c2945bf6 CR3: 0000000029d13000 CR4: 00000000003506e0
DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400
Call Trace:
 <TASK>
 net_free net/core/net_namespace.c:442 [inline]
 net_free net/core/net_namespace.c:436 [inline]
 cleanup_net+0x8bb/0xb10 net/core/net_namespace.c:627
 process_one_work+0x9bf/0x1710 kernel/workqueue.c:2289
 worker_thread+0x669/0x1090 kernel/workqueue.c:2436
 kthread+0x2e8/0x3a0 kernel/kthread.c:376
 ret_from_fork+0x1f/0x30 arch/x86/entry/entry_64.S:308
 </TASK>