rcu: INFO: rcu_preempt self-detected stall on CPU
rcu: 	0-....: (1 GPs behind) idle=fe3/1/0x4000000000000000 softirq=65557/65558 fqs=5247 
	(t=10502 jiffies g=82205 q=1143)
NMI backtrace for cpu 0
CPU: 0 PID: 26970 Comm: syz-executor.2 Not tainted 5.16.0-rc8-next-20220105-syzkaller #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011
Call Trace:
 <IRQ>
 __dump_stack lib/dump_stack.c:88 [inline]
 dump_stack_lvl+0xcd/0x134 lib/dump_stack.c:106
 nmi_cpu_backtrace.cold+0x47/0x144 lib/nmi_backtrace.c:111
 nmi_trigger_cpumask_backtrace+0x1b3/0x230 lib/nmi_backtrace.c:62
 trigger_single_cpu_backtrace include/linux/nmi.h:164 [inline]
 rcu_dump_cpu_stacks+0x262/0x3f0 kernel/rcu/tree_stall.h:343
 print_cpu_stall kernel/rcu/tree_stall.h:604 [inline]
 check_cpu_stall kernel/rcu/tree_stall.h:688 [inline]
 rcu_pending kernel/rcu/tree.c:3921 [inline]
 rcu_sched_clock_irq.cold+0x5c/0x759 kernel/rcu/tree.c:2626
 update_process_times+0x16d/0x200 kernel/time/timer.c:1785
 tick_sched_handle+0x9b/0x180 kernel/time/tick-sched.c:226
 tick_sched_timer+0x1b0/0x2d0 kernel/time/tick-sched.c:1428
 __run_hrtimer kernel/time/hrtimer.c:1685 [inline]
 __hrtimer_run_queues+0x1c0/0xe50 kernel/time/hrtimer.c:1749
 hrtimer_interrupt+0x31c/0x790 kernel/time/hrtimer.c:1811
 local_apic_timer_interrupt arch/x86/kernel/apic/apic.c:1086 [inline]
 __sysvec_apic_timer_interrupt+0x146/0x530 arch/x86/kernel/apic/apic.c:1103
 sysvec_apic_timer_interrupt+0x8e/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:signal_pending_state include/linux/sched/signal.h:387 [inline]
RIP: 0010:rwsem_down_write_slowpath+0x576/0x1110 kernel/locking/rwsem.c:1120
Code: 80 00 00 00 f0 4c 0f b1 65 00 0f 85 e1 03 00 00 41 83 e4 04 0f 84 26 02 00 00 c6 84 24 e8 00 00 00 01 4c 89 f7 e8 aa 72 fd 07 <f7> 44 24 04 01 01 00 00 74 71 be 08 00 00 00 4c 89 ef e8 f3 6b 67
RSP: 0018:ffffc9001093f6b0 EFLAGS: 00000286
RAX: 0000000080000000 RBX: dffffc0000000000 RCX: 0000000000000000
RDX: 0000000000000001 RSI: 0000000000000001 RDI: 0000000000000001
RBP: ffff888010c678d8 R08: 0000000000000001 R09: ffffffff8ffbb94f
R10: 0000000000000001 R11: 0000000000000001 R12: 1ffffffff1701e30
R13: ffff888075df57c0 R14: ffff888010c678f0 R15: ffffc90002cc7ac8
 __down_write_common kernel/locking/rwsem.c:1259 [inline]
 __down_write_common kernel/locking/rwsem.c:1256 [inline]
 __down_write kernel/locking/rwsem.c:1268 [inline]
 down_write+0x135/0x150 kernel/locking/rwsem.c:1515
 kernfs_drain fs/kernfs/dir.c:486 [inline]
 __kernfs_remove+0x5fc/0xb20 fs/kernfs/dir.c:1367
 kernfs_remove_by_name_ns+0xa8/0x110 fs/kernfs/dir.c:1565
 kernfs_remove_by_name include/linux/kernfs.h:574 [inline]
 remove_files+0x96/0x1c0 fs/sysfs/group.c:28
 sysfs_remove_group+0x87/0x170 fs/sysfs/group.c:288
 sysfs_remove_groups fs/sysfs/group.c:312 [inline]
 sysfs_remove_groups+0x5c/0xa0 fs/sysfs/group.c:304
 __kobject_del+0x89/0x200 lib/kobject.c:611
 kobject_del lib/kobject.c:643 [inline]
 kobject_del+0x3c/0x60 lib/kobject.c:635
 __ext4_fill_super fs/ext4/super.c:5453 [inline]
 ext4_fill_super+0xb044/0xe800 fs/ext4/super.c:5551
 get_tree_bdev+0x440/0x760 fs/super.c:1292
 vfs_get_tree+0x89/0x2f0 fs/super.c:1497
 do_new_mount fs/namespace.c:3010 [inline]
 path_mount+0x1320/0x1fa0 fs/namespace.c:3340
 do_mount fs/namespace.c:3353 [inline]
 __do_sys_mount fs/namespace.c:3561 [inline]
 __se_sys_mount fs/namespace.c:3538 [inline]
 __x64_sys_mount+0x27f/0x300 fs/namespace.c:3538
 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: 0033:0x7f0be1fef3ca
Code: 48 c7 c2 bc ff ff ff f7 d8 64 89 02 b8 ff ff ff ff eb d2 e8 b8 04 00 00 0f 1f 84 00 00 00 00 00 49 89 ca b8 a5 00 00 00 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:00007f0be0962f88 EFLAGS: 00000206 ORIG_RAX: 00000000000000a5
RAX: ffffffffffffffda RBX: 0000000020000200 RCX: 00007f0be1fef3ca
RDX: 0000000020000000 RSI: 0000000020000100 RDI: 00007f0be0962fe0
RBP: 00007f0be0963020 R08: 00007f0be0963020 R09: 0000000020000000
R10: 0000000000000000 R11: 0000000000000206 R12: 0000000020000000
R13: 0000000020000100 R14: 00007f0be0962fe0 R15: 00000000200000c0
 </TASK>
----------------
Code disassembly (best guess):
   0:	80 00 00             	addb   $0x0,(%rax)
   3:	00 f0                	add    %dh,%al
   5:	4c 0f b1 65 00       	cmpxchg %r12,0x0(%rbp)
   a:	0f 85 e1 03 00 00    	jne    0x3f1
  10:	41 83 e4 04          	and    $0x4,%r12d
  14:	0f 84 26 02 00 00    	je     0x240
  1a:	c6 84 24 e8 00 00 00 	movb   $0x1,0xe8(%rsp)
  21:	01
  22:	4c 89 f7             	mov    %r14,%rdi
  25:	e8 aa 72 fd 07       	callq  0x7fd72d4
* 2a:	f7 44 24 04 01 01 00 	testl  $0x101,0x4(%rsp) <-- trapping instruction
  31:	00
  32:	74 71                	je     0xa5
  34:	be 08 00 00 00       	mov    $0x8,%esi
  39:	4c 89 ef             	mov    %r13,%rdi
  3c:	e8                   	.byte 0xe8
  3d:	f3                   	repz
  3e:	6b                   	.byte 0x6b
  3f:	67                   	addr32