------------[ cut here ]------------
refcount_t: decrement hit 0; leaking memory.
WARNING: CPU: 1 PID: 14799 at lib/refcount.c:31 refcount_warn_saturate+0xbf/0x1e0 lib/refcount.c:31
Modules linked in:
CPU: 1 PID: 14799 Comm: kworker/u4:7 Not tainted 5.16.0-rc1-next-20211118-syzkaller #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011
Workqueue: netns cleanup_net
RIP: 0010:refcount_warn_saturate+0xbf/0x1e0 lib/refcount.c:31
Code: 1d d7 4f a5 09 31 ff 89 de e8 8d 9d a0 fd 84 db 75 e0 e8 a4 99 a0 fd 48 c7 c7 e0 71 04 8a c6 05 b7 4f a5 09 01 e8 2b a6 26 05 <0f> 0b eb c4 e8 88 99 a0 fd 0f b6 1d a6 4f a5 09 31 ff 89 de e8 58
RSP: 0018:ffffc90002fafa10 EFLAGS: 00010286
RAX: 0000000000000000 RBX: 0000000000000000 RCX: 0000000000000000
RDX: ffff88801951d7c0 RSI: ffffffff815f11d8 RDI: fffff520005f5f34
RBP: 0000000000000004 R08: 0000000000000000 R09: 0000000000000000
R10: ffffffff815eaf7e R11: 0000000000000000 R12: 0000000000000001
R13: ffffc90002fafb68 R14: ffff88808537a5b0 R15: ffff888021b7e5a0
FS:  0000000000000000(0000) GS:ffff8880b9c00000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 00007fb6f5d97f80 CR3: 00000000831c4000 CR4: 00000000003506f0
DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400
Call Trace:
 <TASK>
 __refcount_dec include/linux/refcount.h:344 [inline]
 refcount_dec include/linux/refcount.h:359 [inline]
 dev_put include/linux/netdevice.h:3817 [inline]
 unregister_netdevice_many+0x12c9/0x1790 net/core/dev.c:10450
 default_device_exit_batch+0x2fa/0x3c0 net/core/dev.c:10943
 ops_exit_list+0x10d/0x160 net/core/net_namespace.c:171
 cleanup_net+0x4ea/0xb00 net/core/net_namespace.c:593
 process_one_work+0x9b2/0x1690 kernel/workqueue.c:2298
 worker_thread+0x658/0x11f0 kernel/workqueue.c:2445
 kthread+0x405/0x4f0 kernel/kthread.c:327
 ret_from_fork+0x1f/0x30 arch/x86/entry/entry_64.S:295
 </TASK>