WARNING: CPU: 0 PID: 31334 at lib/refcount.c:28 refcount_warn_saturate+0x1d1/0x1e0 lib/refcount.c:28
Modules linked in:
CPU: 0 PID: 31334 Comm: syz-executor.1 Not tainted 5.16.0-rc3-syzkaller #0
Hardware name: QEMU Standard PC (Q35 + ICH9, 2009), BIOS 1.14.0-2 04/01/2014
RIP: 0010:refcount_warn_saturate+0x1d1/0x1e0 lib/refcount.c:28
Code: e9 db fe ff ff 48 89 df e8 cc 75 e2 fd e9 8a fe ff ff e8 c2 3a 9c fd 48 c7 c7 80 4b 04 8a c6 05 a3 c8 a1 09 01 e8 28 e1 25 05 <0f> 0b e9 af fe ff ff 0f 1f 84 00 00 00 00 00 41 56 41 55 41 54 55
RSP: 0018:ffffc90000007d00 EFLAGS: 00010282
RAX: 0000000000000000 RBX: 0000000000000000 RCX: 0000000000000000
RDX: ffff888024dc0180 RSI: ffffffff815e5208 RDI: fffff52000000f92
RBP: 0000000000000003 R08: 0000000000000000 R09: 0000000000000001
R10: ffffffff815defae R11: 0000000000000000 R12: ffff88801ae56020
R13: 1ffff92000000fa8 R14: ffffffff886232d0 R15: 0000000000000000
FS:  00007fae8ab48700(0000) GS:ffff88802ca00000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 00007f35fc379058 CR3: 000000006f242000 CR4: 0000000000150ef0
DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000001
DR3: 0000000000000000 DR6: 00000000ffff0ff0 DR7: 0000000000000400
Call Trace:
 <IRQ>
 __refcount_sub_and_test include/linux/refcount.h:283 [inline]
 __refcount_dec_and_test include/linux/refcount.h:315 [inline]
 refcount_dec_and_test include/linux/refcount.h:333 [inline]
 sctp_transport_put+0x138/0x180 net/sctp/transport.c:486
 call_timer_fn+0x1a5/0x6b0 kernel/time/timer.c:1421
 expire_timers kernel/time/timer.c:1466 [inline]
 __run_timers.part.0+0x675/0xa20 kernel/time/timer.c:1734
 __run_timers kernel/time/timer.c:1715 [inline]
 run_timer_softirq+0xb3/0x1d0 kernel/time/timer.c:1747
 __do_softirq+0x29b/0x9c2 kernel/softirq.c:558
 invoke_softirq kernel/softirq.c:432 [inline]
 __irq_exit_rcu+0x123/0x180 kernel/softirq.c:636
 irq_exit_rcu+0x5/0x20 kernel/softirq.c:648
 sysvec_apic_timer_interrupt+0x93/0xc0 arch/x86/kernel/apic/apic.c:1097
 </IRQ>
 <TASK>
 asm_sysvec_apic_timer_interrupt+0x12/0x20 arch/x86/include/asm/idtentry.h:638
RIP: 0010:finish_task_switch.isra.0+0x323/0xb80 kernel/sched/core.c:4852
Code: b3 53 f4 07 85 c0 75 02 0f 0b 48 85 db 0f 85 25 01 00 00 4c 89 f7 e8 fc f7 ff ff e8 07 4c 2d 00 fb 65 48 8b 1c 25 40 70 02 00 <48> 8d bb 80 15 00 00 48 b8 00 00 00 00 00 fc ff df 48 89 fa 48 c1
RSP: 0018:ffffc9000313f8c8 EFLAGS: 00000202
RAX: 00000000000028f7 RBX: ffff888024dc0180 RCX: 1ffffffff1ff06e6
RDX: 0000000000000000 RSI: 0000000000000001 RDI: 0000000000000000
RBP: ffffc9000313f910 R08: 0000000000000001 R09: ffffffff8ff75a27
R10: 0000000000000001 R11: 0000000000000000 R12: ffff88802ca3a858
R13: ffff88806ff58000 R14: ffff88802ca39b00 R15: ffff88802ca3a538
 context_switch kernel/sched/core.c:4975 [inline]
 __schedule+0xaa2/0x4940 kernel/sched/core.c:6253
 preempt_schedule_common+0x45/0xc0 kernel/sched/core.c:6419
 preempt_schedule_thunk+0x16/0x18 arch/x86/entry/thunk_64.S:35
 __raw_spin_unlock include/linux/spinlock_api_smp.h:143 [inline]
 _raw_spin_unlock+0x36/0x40 kernel/locking/spinlock.c:186
 spin_unlock include/linux/spinlock.h:389 [inline]
 d_walk+0x47e/0x8c0 fs/dcache.c:1415
 shrink_dcache_parent+0x94/0x3c0 fs/dcache.c:1600
 d_invalidate fs/dcache.c:1712 [inline]
 d_invalidate+0x13f/0x280 fs/dcache.c:1697
 simple_recursive_removal+0x347/0x760 fs/libfs.c:290
 debugfs_remove fs/debugfs/inode.c:732 [inline]
 debugfs_remove+0x59/0x80 fs/debugfs/inode.c:726
 bdi_debug_unregister mm/backing-dev.c:119 [inline]
 bdi_unregister+0x3c5/0x5a0 mm/backing-dev.c:949
 del_gendisk+0x6bc/0x860 block/genhd.c:608
 loop_remove+0x39/0xf0 drivers/block/loop.c:2080
 loop_control_remove drivers/block/loop.c:2137 [inline]
 loop_control_ioctl+0x449/0x4d0 drivers/block/loop.c:2175
 vfs_ioctl fs/ioctl.c:51 [inline]
 __do_sys_ioctl fs/ioctl.c:874 [inline]
 __se_sys_ioctl fs/ioctl.c:860 [inline]
 __x64_sys_ioctl+0x193/0x200 fs/ioctl.c:860
 do_syscall_x64 arch/x86/entry/common.c:50 [inline]
 do_syscall_64+0x35/0xb0 arch/x86/entry/common.c:80
 entry_SYSCALL_64_after_hwframe+0x44/0xae
RIP: 0033:0x7fae8bc14ae9
Code: ff ff c3 66 2e 0f 1f 84 00 00 00 00 00 0f 1f 40 00 48 89 f8 48 89 f7 48 89 d6 48 89 ca 4d 89 c2 4d 89 c8 4c 8b 4c 24 08 0f 05 <48> 3d 01 f0 ff ff 73 01 c3 48 c7 c1 bc ff ff ff f7 d8 64 89 01 48
RSP: 002b:00007fae8ab48188 EFLAGS: 00000246 ORIG_RAX: 0000000000000010
RAX: ffffffffffffffda RBX: 00007fae8bd280f0 RCX: 00007fae8bc14ae9
RDX: 000000000000000b RSI: 0000000000004c81 RDI: 0000000000000006
RBP: 00007fae8bc6eff7 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000
R13: 00007ffea7ed9d1f R14: 00007fae8ab48300 R15: 0000000000022000
 </TASK>
----------------
Code disassembly (best guess), 4 bytes skipped:
   0:	85 c0                	test   %eax,%eax
   2:	75 02                	jne    0x6
   4:	0f 0b                	ud2
   6:	48 85 db             	test   %rbx,%rbx
   9:	0f 85 25 01 00 00    	jne    0x134
   f:	4c 89 f7             	mov    %r14,%rdi
  12:	e8 fc f7 ff ff       	callq  0xfffff813
  17:	e8 07 4c 2d 00       	callq  0x2d4c23
  1c:	fb                   	sti
  1d:	65 48 8b 1c 25 40 70 	mov    %gs:0x27040,%rbx
  24:	02 00
* 26:	48 8d bb 80 15 00 00 	lea    0x1580(%rbx),%rdi <-- trapping instruction
  2d:	48 b8 00 00 00 00 00 	movabs $0xdffffc0000000000,%rax
  34:	fc ff df
  37:	48 89 fa             	mov    %rdi,%rdx
  3a:	48                   	rex.W
  3b:	c1                   	.byte 0xc1