------------[ cut here ]------------
WARNING: CPU: 2 PID: 5186 at kernel/workqueue.c:1728 __queue_work+0xdc6/0x11d0 kernel/workqueue.c:1727
Modules linked in:
CPU: 2 PID: 5186 Comm: kworker/2:2 Not tainted 6.8.0-rc7-syzkaller-00051-g67be068d31d4 #0
Hardware name: QEMU Standard PC (Q35 + ICH9, 2009), BIOS 1.16.2-debian-1.16.2-1 04/01/2014
Workqueue: events free_ipc

RIP: 0010:__queue_work+0xdc6/0x11d0 kernel/workqueue.c:1727
Code: 07 83 c0 03 38 d0 7c 09 84 d2 74 05 e8 33 ce 8d 00 8b 5b 2c 31 ff 83 e3 20 89 de e8 44 36 33 00 85 db 75 56 e8 5b 3b 33 00 90 <0f> 0b 90 e9 ac f8 ff ff e8 4d 3b 33 00 90 0f 0b 90 e9 5b f8 ff ff
RSP: 0018:ffffc90000520c28 EFLAGS: 00010046
RAX: 0000000000000000 RBX: 0000000000000100 RCX: ffffffff8158a92c
RDX: ffff88801df0a400 RSI: ffffffff8158a985 RDI: 0000000000000005
RBP: ffff888047474c58 R08: 0000000000000005 R09: 0000000000000000
R10: 0000000000000100 R11: 0000000000000004 R12: ffff888047474c10
R13: 0000000080000101 R14: ffffffff8158b340 R15: ffff888047470800
FS:  0000000000000000(0000) GS:ffff88802c400000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 00000000f7420044 CR3: 000000000d378000 CR4: 0000000000350ef0
DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400
Call Trace:
 <IRQ>
 call_timer_fn+0x193/0x5a0 kernel/time/timer.c:1700
 expire_timers kernel/time/timer.c:1746 [inline]
 __run_timers+0x57e/0xaa0 kernel/time/timer.c:2038
 run_timer_softirq+0x58/0xd0 kernel/time/timer.c:2051
 __do_softirq+0x21c/0x8e7 kernel/softirq.c:553
 invoke_softirq kernel/softirq.c:427 [inline]
 __irq_exit_rcu kernel/softirq.c:632 [inline]
 irq_exit_rcu+0xbb/0x120 kernel/softirq.c:644
 sysvec_apic_timer_interrupt+0x95/0xb0 arch/x86/kernel/apic/apic.c:1076
 </IRQ>
 <TASK>
 asm_sysvec_apic_timer_interrupt+0x1a/0x20 arch/x86/include/asm/idtentry.h:649
RIP: 0010:lock_acquire+0x1ef/0x520 kernel/locking/lockdep.c:5722
Code: c1 05 cd fe 96 7e 83 f8 01 0f 85 b8 02 00 00 9c 58 f6 c4 02 0f 85 a3 02 00 00 48 85 ed 74 01 fb 48 b8 00 00 00 00 00 fc ff df <48> 01 c3 48 c7 03 00 00 00 00 48 c7 43 08 00 00 00 00 48 8b 84 24
RSP: 0018:ffffc90003be7870 EFLAGS: 00000206
RAX: dffffc0000000000 RBX: 1ffff9200077cf10 RCX: 0000000000000001
RDX: 0000000000000001 RSI: ffffffff8aecb3a0 RDI: ffffffff8b4dbf00
RBP: 0000000000000200 R08: 00000000000f5658 R09: fffffbfff27885b4
R10: ffffffff93c42da7 R11: 0000000000000002 R12: 0000000000000001
R13: 0000000000000000 R14: ffff888021656998 R15: 0000000000000000
 __raw_spin_lock include/linux/spinlock_api_smp.h:133 [inline]
 _raw_spin_lock+0x2e/0x40 kernel/locking/spinlock.c:154
 spin_lock include/linux/spinlock.h:351 [inline]
 inode_sb_list_del fs/inode.c:503 [inline]
 evict+0x179/0x6c0 fs/inode.c:654
 iput_final fs/inode.c:1739 [inline]
 iput.part.0+0x563/0x7b0 fs/inode.c:1765
 iput+0x5c/0x80 fs/inode.c:1755
 dentry_unlink_inode+0x295/0x440 fs/dcache.c:400
 __dentry_kill+0x1d0/0x600 fs/dcache.c:603
 dput.part.0+0x4b1/0x9b0 fs/dcache.c:845
 dput fs/dcache.c:835 [inline]
 do_one_tree fs/dcache.c:1541 [inline]
 shrink_dcache_for_umount+0x131/0x390 fs/dcache.c:1555
 generic_shutdown_super+0x76/0x3d0 fs/super.c:619
 kill_anon_super fs/super.c:1225 [inline]
 kill_litter_super+0x70/0xa0 fs/super.c:1235
 deactivate_locked_super+0xbe/0x1a0 fs/super.c:472
 deactivate_super+0xde/0x100 fs/super.c:505
 cleanup_mnt+0x222/0x450 fs/namespace.c:1267
 mntput_no_expire+0x824/0xaf0 fs/namespace.c:1353
 mntput+0x6b/0x90 fs/namespace.c:1363
 free_ipc_ns ipc/namespace.c:152 [inline]
 free_ipc+0x184/0x2d0 ipc/namespace.c:179
 process_one_work+0x835/0x1570 kernel/workqueue.c:2633
 process_scheduled_works kernel/workqueue.c:2706 [inline]
 worker_thread+0x8b9/0x12a0 kernel/workqueue.c:2787
 kthread+0x2c6/0x3b0 kernel/kthread.c:388
 ret_from_fork+0x45/0x80 arch/x86/kernel/process.c:147
 ret_from_fork_asm+0x1b/0x30 arch/x86/entry/entry_64.S:243
 </TASK>
----------------
Code disassembly (best guess):
   0:	c1 05 cd fe 96 7e 83 	roll   $0x83,0x7e96fecd(%rip)        # 0x7e96fed4
   7:	f8                   	clc
   8:	01 0f                	add    %ecx,(%rdi)
   a:	85 b8 02 00 00 9c    	test   %edi,-0x63fffffe(%rax)
  10:	58                   	pop    %rax
  11:	f6 c4 02             	test   $0x2,%ah
  14:	0f 85 a3 02 00 00    	jne    0x2bd
  1a:	48 85 ed             	test   %rbp,%rbp
  1d:	74 01                	je     0x20
  1f:	fb                   	sti
  20:	48 b8 00 00 00 00 00 	movabs $0xdffffc0000000000,%rax
  27:	fc ff df
* 2a:	48 01 c3             	add    %rax,%rbx <-- trapping instruction
  2d:	48 c7 03 00 00 00 00 	movq   $0x0,(%rbx)
  34:	48 c7 43 08 00 00 00 	movq   $0x0,0x8(%rbx)
  3b:	00
  3c:	48                   	rex.W
  3d:	8b                   	.byte 0x8b
  3e:	84                   	.byte 0x84
  3f:	24                   	.byte 0x24