------------[ cut here ]------------
WARNING: CPU: 0 PID: 8242 at fs/namespace.c:1187 mntput_no_expire+0xada/0xcd0 fs/namespace.c:1187
Modules linked in:
CPU: 0 PID: 8242 Comm: kworker/0:6 Not tainted 5.16.0-rc2-syzkaller #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011
Workqueue: events free_ipc
RIP: 0010:mntput_no_expire+0xada/0xcd0 fs/namespace.c:1187
Code: 30 84 c0 0f 84 b9 fe ff ff 3c 03 0f 8f b1 fe ff ff 4c 89 44 24 10 e8 e5 48 ec ff 4c 8b 44 24 10 e9 9d fe ff ff e8 a6 8b a5 ff <0f> 0b e9 19 fd ff ff e8 9a 8b a5 ff e8 c5 d1 71 07 31 ff 89 c5 89
RSP: 0018:ffffc9000c787c08 EFLAGS: 00010293
RAX: 0000000000000000 RBX: 1ffff920018f0f87 RCX: 0000000000000000
RDX: ffff888037098000 RSI: ffffffff81d20dba RDI: 0000000000000003
RBP: ffff88802154e480 R08: 0000000000000000 R09: ffffffff8ff71a0f
R10: ffffffff81d20ad1 R11: 0000000000000000 R12: 0000000000000008
R13: ffffc9000c787c58 R14: 00000000ffffffff R15: 0000000000000002
FS:  0000000000000000(0000) GS:ffff8880b9c00000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 00007ffc3e7535c7 CR3: 00000000718d3000 CR4: 00000000003506f0
DR0: 0000000000000000 DR1: 0000000000000000 DR2: 000000000000d8e8
DR3: 0000000000000000 DR6: 00000000ffff0ff0 DR7: 0000000000000400
Call Trace:
 <TASK>
 mntput fs/namespace.c:1233 [inline]
 kern_unmount fs/namespace.c:4369 [inline]
 kern_unmount+0xb5/0xe0 fs/namespace.c:4363
 free_ipc_ns ipc/namespace.c:123 [inline]
 free_ipc+0xf0/0x200 ipc/namespace.c:141
 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>