INFO: task syz.4.262:7867 blocked for more than 143 seconds.
      Not tainted syzkaller #0
"echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message.
task:syz.4.262       state:D stack:28104 pid:7867  tgid:7866  ppid:6541   task_flags:0x400140 flags:0x00004004
Call Trace:
 <TASK>
 __schedule+0x1798/0x4cc0
 schedule+0x165/0x360
 schedule_preempt_disabled+0x13/0x30
 rwsem_down_read_slowpath+0x5fd/0x8f0
 down_read+0x98/0x2e0
 super_lock+0x2a9/0x3b0
 __iterate_supers+0x126/0x290
 ksys_sync+0x94/0x150
 __ia32_sys_sync+0xe/0x20
 do_syscall_64+0xfa/0x3b0
 entry_SYSCALL_64_after_hwframe+0x77/0x7f
RIP: 0033:0x7f607cd8eba9
RSP: 002b:00007f607dc5e038 EFLAGS: 00000246 ORIG_RAX: 00000000000000a2
RAX: ffffffffffffffda RBX: 00007f607cfd5fa0 RCX: 00007f607cd8eba9
RDX: 0000000000000000 RSI: 0000000000000000 RDI: 0000000000000000
RBP: 00007f607cfd5fa0 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000
R13: 00007f607cfd6038 R14: 00007f607cfd5fa0 R15: 00007ffe6d98b4c8
 </TASK>

Showing all locks held in the system:
1 lock held by khungtaskd/34:
 #0: ffffffff8e13a0e0 (rcu_read_lock){....}-{1:3}, at: debug_show_all_locks+0x2e/0x180
5 locks held by kworker/u9:4/4950:
 #0: 
ffff88804b039f98 (&rq->__lock){-.-.}-{2:2}, at: raw_spin_rq_lock_nested+0x2a/0x140
 #1: ffff88804b024008 (psi_seq){-.-.}-{0:0}, at: psi_task_switch+0x53/0x880
 #2: ffff88804b025918 (&base->lock){-.-.}-{2:2}, at: __mod_timer+0x1ae/0xf30
 #3: ffffffff99d1b208 (&obj_hash[i].lock){-.-.}-{2:2}, at: debug_object_activate+0xbb/0x420
 #4: ffffffff8e13a0e0 (rcu_read_lock){....}-{1:3}, at: unwind_next_frame+0xa5/0x2390
2 locks held by dhcpcd/5593:
 #0: ffff88804b039f98 (&rq->__lock){-.-.}-{2:2}, at: raw_spin_rq_lock_nested+0x2a/0x140
 #1: ffff88804b024008 (psi_seq){-.-.}-{0:0}, at: psi_task_switch+0x53/0x880
2 locks held by getty/5674:
 #0: ffff8880276240a0 (&tty->ldisc_sem){++++}-{0:0}, at: tty_ldisc_ref_wait+0x25/0x70
 #1: ffffc900029032f0 (&ldata->atomic_read_lock){+.+.}-{4:4}, at: n_tty_read+0x43e/0x1400
8 locks held by kworker/u8:2/5677:
2 locks held by syz-executor/5862:
2 locks held by dhcpcd/6909:
 #0: ffff88802fd50208 (&sb->s_type->i_mutex_key#11){+.+.}-{4:4}, at: sock_close+0x9b/0x240
 #1: ffffffff8e13fb78 (rcu_state.exp_mutex){+.+.}-{4:4}, at: synchronize_rcu_expedited+0x3b9/0x730
1 lock held by syz.4.262/7867:
 #0: ffff888030c100e0 (&type->s_umount_key#67){++++}-{4:4}, at: super_lock+0x2a9/0x3b0
3 locks held by kworker/0:8/10208:
 #0: ffff88801a480d48 ((wq_completion)events){+.+.}-{0:0}, at: process_scheduled_works+0x9b4/0x17b0
 #1: ffffc9000602fbc0 ((work_completion)(&data->fib_event_work)){+.+.}-{0:0}, at: process_scheduled_works+0x9ef/0x17b0
 #2: ffff888030d3c240 (&data->fib_lock){+.+.}-{4:4}, at: nsim_fib_event_work+0x26b/0x3180
3 locks held by syz-executor/10305:
 #0: ffff88802a3ac0e0 (&type->s_umount_key#58){++++}-{4:4}, at: deactivate_super+0xa9/0xe0
 #1: ffff888133a80278 (&c->state_lock){++++}-{4:4}, at: __bch2_fs_stop+0xf8/0x900
 #2: ffffffff8e13fb78 (rcu_state.exp_mutex){+.+.}-{4:4}, at: synchronize_rcu_expedited+0x2f6/0x730
3 locks held by syz.8.581/10501:
1 lock held by cmp/10505:

=============================================

NMI backtrace for cpu 1
CPU: 1 UID: 0 PID: 34 Comm: khungtaskd Not tainted syzkaller #0 PREEMPT(full) 
Hardware name: QEMU Standard PC (Q35 + ICH9, 2009), BIOS 1.16.2-debian-1.16.2-1 04/01/2014
Call Trace:
 <TASK>
 dump_stack_lvl+0x189/0x250
 nmi_cpu_backtrace+0x39e/0x3d0
 nmi_trigger_cpumask_backtrace+0x17a/0x300
 watchdog+0xf93/0xfe0
 kthread+0x711/0x8a0
 ret_from_fork+0x439/0x7d0
 ret_from_fork_asm+0x1a/0x30
 </TASK>
Sending NMI from CPU 1 to CPUs 0:
NMI backtrace for cpu 0
CPU: 0 UID: 0 PID: 10501 Comm: syz.8.581 Not tainted syzkaller #0 PREEMPT(full) 
Hardware name: QEMU Standard PC (Q35 + ICH9, 2009), BIOS 1.16.2-debian-1.16.2-1 04/01/2014
RIP: 0010:wq_watchdog_touch+0x27/0x180
Code: 90 90 90 66 0f 1f 00 55 41 57 41 56 41 55 41 54 53 89 fb 49 bf 00 00 00 00 00 fc ff df e8 71 94 34 00 4c 6b 25 49 ea 72 0c 64 <4c> 8b 2d 62 ea 72 0c 48 c7 c0 00 12 e1 8d 48 c1 e8 03 42 80 3c 38
RSP: 0018:ffffc90004f26988 EFLAGS: 00000002
RAX: ffffffff818b28ef RBX: 0000000000000000 RCX: ffff8881079b0000
RDX: 0000000000000000 RSI: ffffffff99b008c0 RDI: 0000000000000000
RBP: ffffc90004f26b70 R08: 0000000000000000 R09: ffffffff81a06e4a
R10: dffffc0000000000 R11: ffffffff854e6110 R12: 00000000000036b0
R13: dffffc0000000000 R14: ffffffff99df56f8 R15: dffffc0000000000
FS:  00007f531b69f6c0(0000) GS:ffff8880b8615000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 0000561d4623a950 CR3: 0000000130164000 CR4: 00000000000006f0
Call Trace:
 <TASK>
 serial8250_console_write+0xd7/0x1ba0
 console_flush_all+0x728/0xc40
 console_unlock+0xc4/0x270
 vprintk_emit+0x5b7/0x7a0
 _printk+0xcf/0x120
 set_capacity_and_notify+0x208/0x2d0
 loop_set_size+0x44/0xb0
 loop_configure+0x9f4/0xe50
 lo_ioctl+0x810/0x1c10
 blkdev_ioctl+0x5a8/0x6d0
 __se_sys_ioctl+0xfc/0x170
 do_syscall_64+0xfa/0x3b0
 entry_SYSCALL_64_after_hwframe+0x77/0x7f
RIP: 0033:0x7f531a78e7ab
Code: 00 48 89 44 24 18 31 c0 48 8d 44 24 60 c7 04 24 10 00 00 00 48 89 44 24 08 48 8d 44 24 20 48 89 44 24 10 b8 10 00 00 00 0f 05 <89> c2 3d 00 f0 ff ff 77 1c 48 8b 44 24 18 64 48 2b 04 25 28 00 00
RSP: 002b:00007f531b69edc0 EFLAGS: 00000246 ORIG_RAX: 0000000000000010
RAX: ffffffffffffffda RBX: 0000000000000003 RCX: 00007f531a78e7ab
RDX: 0000000000000007 RSI: 0000000000004c00 RDI: 0000000000000003
RBP: 0000000000000000 R08: 0000000000000000 R09: 0000000000009600
R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000007
R13: 00007f531b69eef0 R14: 00007f531b69eeb0 R15: 00007f5310400000
 </TASK>
