INFO: task syz.3.493:10929 blocked for more than 143 seconds.
      Not tainted syzkaller #0
"echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message.
task:syz.3.493       state:D stack:28904 pid:10929 tgid:10928 ppid:10767  task_flags:0x400040 flags:0x00080002
Call Trace:
 <TASK>
 __schedule+0x1854/0x4d60
 schedule+0x164/0x360
 schedule_preempt_disabled+0x13/0x30
 rwsem_down_read_slowpath+0x61e/0x920
 down_read+0x98/0x2e0
 super_lock+0x2d6/0x3d0
 __iterate_supers+0x126/0x290
 ksys_sync+0xa0/0x170
 __ia32_sys_sync+0xe/0x20
 do_syscall_64+0xf0/0xfa0
 entry_SYSCALL_64_after_hwframe+0x77/0x7f
RIP: 0033:0x7f0d9d79acb9
RSP: 002b:00007f0d9e608028 EFLAGS: 00000246 ORIG_RAX: 00000000000000a2
RAX: ffffffffffffffda RBX: 00007f0d9da15fa0 RCX: 00007f0d9d79acb9
RDX: 0000000000000000 RSI: 0000000000000000 RDI: 0000000000000000
RBP: 00007f0d9da15fa0 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000
R13: 00007f0d9da16038 R14: 00007f0d9da15fa0 R15: 00007fff65ae3768
 </TASK>
INFO: task syz.1.513:11263 blocked for more than 143 seconds.
      Not tainted syzkaller #0
"echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message.
task:syz.1.513       state:D stack:21704 pid:11263 tgid:11262 ppid:10369  task_flags:0x400140 flags:0x00080002
Call Trace:
 <TASK>
 __schedule+0x1854/0x4d60
 schedule+0x164/0x360
 schedule_preempt_disabled+0x13/0x30
 rwsem_down_read_slowpath+0x61e/0x920
 down_read+0x98/0x2e0
 super_lock+0x2d6/0x3d0
 __iterate_supers+0x126/0x290
 ksys_sync+0xa0/0x170
 __ia32_sys_sync+0xe/0x20
 do_syscall_64+0xf0/0xfa0
 entry_SYSCALL_64_after_hwframe+0x77/0x7f
RIP: 0033:0x7fa81539acb9
RSP: 002b:00007fa81618c028 EFLAGS: 00000246 ORIG_RAX: 00000000000000a2
RAX: ffffffffffffffda RBX: 00007fa815615fa0 RCX: 00007fa81539acb9
RDX: 0000000000000000 RSI: 0000000000000000 RDI: 0000000000000000
RBP: 00007fa815615fa0 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000
R13: 00007fa815616038 R14: 00007fa815615fa0 R15: 00007ffc40cbbbc8
 </TASK>
INFO: task syz.1.702:13141 blocked for more than 143 seconds.
      Not tainted syzkaller #0
"echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message.
task:syz.1.702       state:D stack:28904 pid:13141 tgid:13140 ppid:12923  task_flags:0x400040 flags:0x00080002
Call Trace:
 <TASK>
 __schedule+0x1854/0x4d60
 schedule+0x164/0x360
 schedule_preempt_disabled+0x13/0x30
 rwsem_down_read_slowpath+0x61e/0x920
 down_read+0x98/0x2e0
 super_lock+0x2d6/0x3d0
 __iterate_supers+0x126/0x290
 ksys_sync+0xa0/0x170
 __ia32_sys_sync+0xe/0x20
 do_syscall_64+0xf0/0xfa0
 entry_SYSCALL_64_after_hwframe+0x77/0x7f
RIP: 0033:0x7f6a9e19acb9
RSP: 002b:00007f6a9f112028 EFLAGS: 00000246 ORIG_RAX: 00000000000000a2
RAX: ffffffffffffffda RBX: 00007f6a9e415fa0 RCX: 00007f6a9e19acb9
RDX: 0000000000000000 RSI: 0000000000000000 RDI: 0000000000000000
RBP: 00007f6a9e415fa0 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000
R13: 00007f6a9e416038 R14: 00007f6a9e415fa0 R15: 00007ffcfc515db8
 </TASK>

Showing all locks held in the system:
1 lock held by khungtaskd/34:
 #0: ffffffff8e13e760 (rcu_read_lock){....}-{1:3}, at: debug_show_all_locks+0x2e/0x180
2 locks held by getty/5637:
 #0: ffff8881758a50a0 (&tty->ldisc_sem){++++}-{0:0}, at: tty_ldisc_ref_wait+0x25/0x70
 #1: ffffc9000357b2f0 (&ldata->atomic_read_lock){+.+.}-{4:4}, at: n_tty_read+0x45f/0x14a0
1 lock held by syz.3.493/10929:
 #0: ffff88816e66e0e0 (&type->s_umount_key#56){++++}-{4:4}, at: super_lock+0x2d6/0x3d0
1 lock held by syz.1.513/11263:
 #0: ffff88816e66e0e0 (&type->s_umount_key#56){++++}-{4:4}, at: super_lock+0x2d6/0x3d0
3 locks held by syz-executor/12239:
1 lock held by syz.1.702/13141:
 #0: ffff88816e66e0e0 (&type->s_umount_key#56){++++}-{4:4}, at: super_lock+0x2d6/0x3d0
1 lock held by syz.9.889/15117:
 #0: ffff88816e66e0e0 (&type->s_umount_key#56){++++}-{4:4}, at: super_lock+0x289/0x3d0
1 lock held by syz.1.933/15650:
 #0: ffff88816e66e0e0 (&type->s_umount_key#56){++++}-{4:4}, at: super_lock+0x2d6/0x3d0
1 lock held by syz.1.933/15654:
 #0: ffff88816e66e0e0 (&type->s_umount_key#56){++++}-{4:4}, at: super_lock+0x2d6/0x3d0
1 lock held by syz.1.933/15655:
 #0: ffff88816e66e0e0 (&type->s_umount_key#56){++++}-{4:4}, at: super_lock+0x2d6/0x3d0
1 lock held by syz.1.933/15657:
 #0: ffff88816e66e0e0 (&type->s_umount_key#56){++++}-{4:4}, at: super_lock+0x2d6/0x3d0
1 lock held by syz.1.933/15658:
 #0: ffff88816e66e0e0 (&type->s_umount_key#56){++++}-{4:4}, at: super_lock+0x2d6/0x3d0
3 locks held by syz.6.1094/16771:
2 locks held by udevadm/16791:

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

NMI backtrace for cpu 0
CPU: 0 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+0x1a9/0x280
 nmi_cpu_backtrace+0x3a9/0x3e0
 nmi_trigger_cpumask_backtrace+0x17a/0x300
 watchdog+0xf5b/0xfa0
 kthread+0x726/0x8b0
 ret_from_fork+0x4d3/0x870
 ret_from_fork_asm+0x1a/0x30
 </TASK>
Sending NMI from CPU 0 to CPUs 1:
NMI backtrace for cpu 1
CPU: 1 UID: 0 PID: 12239 Comm: syz-executor 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:__writeback_single_inode+0x3d8/0xfe0
Code: 1d 09 49 bd 00 00 00 00 00 fc ff df 43 0f b6 04 2c 84 c0 0f 85 ae 05 00 00 8b 5d 00 89 d8 83 e0 8f 89 45 00 f0 83 44 24 fc 00 <48> 8b 54 24 18 48 83 c2 48 48 89 d0 48 c1 e8 03 42 0f b6 04 28 84
RSP: 0018:ffffc90005d4f5b0 EFLAGS: 00000286
RAX: 0000000000000002 RBX: 0000000000000042 RCX: 0000000000000001
RDX: 0000000000000001 RSI: 0000000000000004 RDI: ffffc90005d4f520
RBP: ffff8881aac012c0 R08: 0000000000000003 R09: 0000000000000004
R10: dffffc0000000000 R11: fffff52000ba9ea4 R12: 1ffff11035580258
R13: dffffc0000000000 R14: 0000000000000000 R15: ffff8881aac01270
FS:  0000555581476500(0000) GS:ffff8882a9d12000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 00007fe11a24d580 CR3: 00000001ba472000 CR4: 00000000000006f0
Call Trace:
 <TASK>
 writeback_single_inode+0x1f9/0x6a0
 sync_inode_metadata+0x122/0x1d0
 f2fs_write_checkpoint+0xb79/0x2480
 kill_f2fs_super+0x302/0x720
 deactivate_locked_super+0xbc/0x130
 cleanup_mnt+0x437/0x4d0
 task_work_run+0x1d9/0x270
 exit_to_user_mode_loop+0xe7/0x120
 do_syscall_64+0x2b3/0xfa0
 entry_SYSCALL_64_after_hwframe+0x77/0x7f
RIP: 0033:0x7fbde4b9bf17
Code: a2 c7 05 7c 96 24 00 00 00 00 00 eb 96 e8 e1 12 00 00 90 31 f6 e9 09 00 00 00 66 0f 1f 84 00 00 00 00 00 b8 a6 00 00 00 0f 05 <48> 3d 00 f0 ff ff 77 01 c3 48 c7 c2 e8 ff ff ff f7 d8 64 89 02 b8
RSP: 002b:00007ffcd798c6c8 EFLAGS: 00000246 ORIG_RAX: 00000000000000a6
RAX: 0000000000000000 RBX: 00007fbde4c0471f RCX: 00007fbde4b9bf17
RDX: 0000000000000000 RSI: 0000000000000009 RDI: 00007ffcd798c780
RBP: 00007ffcd798c780 R08: 00007ffcd798d780 R09: 00000000ffffffff
R10: 0000000000000000 R11: 0000000000000246 R12: 00007ffcd798d810
R13: 00007fbde4c0471f R14: 00000000000421dc R15: 00007ffcd798d850
 </TASK>
