INFO: task syz.9.3528:8522 blocked for more than 143 seconds.
      Not tainted syzkaller #0
"echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message.
task:syz.9.3528      state:D stack:24552 pid:8522  tgid:8521  ppid:7676   task_flags:0x400140 flags:0x00080002
Call Trace:
 <TASK>
 __schedule+0x17d9/0x56c0
 schedule+0x164/0x2b0
 schedule_preempt_disabled+0x13/0x30
 rwsem_down_read_slowpath+0x6ba/0x920
 down_read+0x9c/0x330
 super_lock+0x2d6/0x3d0
 user_get_super+0xc8/0x120
 __se_sys_quotactl+0x538/0x9a0
 do_syscall_64+0x174/0x580
 entry_SYSCALL_64_after_hwframe+0x77/0x7f
RIP: 0033:0x7fa4a9d9ce59
RSP: 002b:00007fa4aac2c028 EFLAGS: 00000246 ORIG_RAX: 00000000000000b3
RAX: ffffffffffffffda RBX: 00007fa4aa015fa0 RCX: 00007fa4a9d9ce59
RDX: 0000000000000000 RSI: 00002000000000c0 RDI: ffffffff80000901
RBP: 00007fa4a9e32e6f R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000
R13: 00007fa4aa016038 R14: 00007fa4aa015fa0 R15: 00007ffe5b9f20d8
 </TASK>
INFO: task syz.7.3531:8542 blocked for more than 143 seconds.
      Not tainted syzkaller #0
"echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message.
task:syz.7.3531      state:D stack:24144 pid:8542  tgid:8541  ppid:7586   task_flags:0x400140 flags:0x00080002
Call Trace:
 <TASK>
 __schedule+0x17d9/0x56c0
 schedule+0x164/0x2b0
 schedule_preempt_disabled+0x13/0x30
 rwsem_down_read_slowpath+0x6ba/0x920
 down_read+0x9c/0x330
 super_lock+0x2d6/0x3d0
 __iterate_supers+0x120/0x240
 __se_sys_quotactl+0x3a0/0x9a0
 do_syscall_64+0x174/0x580
 entry_SYSCALL_64_after_hwframe+0x77/0x7f
RIP: 0033:0x7fa90db9ce59
RSP: 002b:00007fa90ea3b028 EFLAGS: 00000246
 ORIG_RAX: 00000000000000b3
RAX: ffffffffffffffda RBX: 00007fa90de15fa0 RCX: 00007fa90db9ce59
RDX: 0000000000000000 RSI: 0000000000000000 RDI: ffffffff80000102
RBP: 00007fa90dc32e6f R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000
R13: 00007fa90de16038 R14: 00007fa90de15fa0 R15: 00007ffde0feeef8
 </TASK>

Showing all locks held in the system:
1 lock held by khungtaskd/34:
 #0: ffffffff8e959c20 (rcu_read_lock){....}-{1:3}, at: debug_show_all_locks+0x2e/0x180
2 locks held by getty/5438:
 #0: ffff8881111b40a0 (&tty->ldisc_sem){++++}-{0:0}, at: tty_ldisc_ref_wait+0x25/0x70
 #1: ffffc900034732e8 (&ldata->atomic_read_lock){+.+.}-{4:4}, at: n_tty_read+0x45a/0x1360
3 locks held by kworker/1:8/7159:
 #0: ffff88810006b140 ((wq_completion)events){+.+.}-{0:0}, at: process_scheduled_works+0xa20/0x14e0
 #1: ffffc9000277fc40 ((work_completion)(&data->fib_event_work)){+.+.}-{0:0}, at: process_scheduled_works+0xa20/0x14e0
 #2: ffff888173c6e250 (&data->fib_lock){+.+.}-{4:4}, at: nsim_fib_event_work+0x1fd/0x3b0
2 locks held by syz-executor/5759:
1 lock held by syz.9.3528/8522:
 #0: ffff88811b2920d8 (&type->s_umount_key#100){++++}-{4:4}, at: super_lock+0x2d6/0x3d0
1 lock held by syz.7.3531/8542:
 #0: ffff88811b2920d8 (&type->s_umount_key#100){++++}-{4:4}, at: super_lock+0x2d6/0x3d0
1 lock held by syz.9.3701/10681:
 #0: ffff88811b2920d8 (&type->s_umount_key#100){++++}-{4:4}, at: super_lock+0x2d6/0x3d0
1 lock held by udevd/11950:
 #0: ffff88816b80a350 (&disk->open_mutex){+.+.}-{4:4}, at: bdev_release+0x1b8/0x690
1 lock held by syz.7.3875/12365:
 #0: ffff88811b2920d8 (&type->s_umount_key#100){++++}-{4:4}, at: super_lock+0x2d6/0x3d0
4 locks held by syz-executor/13353:
1 lock held by syz.0.3928/13366:
 #0: ffff88811b2920d8 (&type->s_umount_key#100){++++}-{4:4}, at: super_lock+0x2d6/0x3d0
1 lock held by syz.5.3938/13903:
1 lock held by syz.5.3938/13912:
 #0: ffff88816b80a350 (&disk->open_mutex){+.+.}-{4:4}, at: bdev_open+0xde/0xd70

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

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+0xe8/0x150
 nmi_cpu_backtrace+0x274/0x2d0
 nmi_trigger_cpumask_backtrace+0x17a/0x380
 sys_info+0x135/0x170
 watchdog+0xfd7/0x1030
 kthread+0x388/0x470
 ret_from_fork+0x514/0xb70
 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: 5759 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:__lock_acquire+0x714/0x2cf0
Code: 83 ff 31 0f 83 cd 23 00 00 4b 8d 04 bf 4d 89 ec 41 8b 6d 20 41 8b 84 c6 98 0b 00 00 31 e8 25 00 60 00 00 0f 95 c1 89 4c 24 20 <31> c9 f7 d8 48 19 c9 48 09 cb 48 83 bc 24 20 01 00 00 00 75 62 e9
RSP: 0018:ffffc90004caf5b8 EFLAGS: 00000046
RAX: 0000000000000000 RBX: 9cdc96dfd1b8cf59 RCX: ffffffff93f0fc00
RDX: 0000000000000008 RSI: ffff88810b9e4770 RDI: ffff88810b9e3b80
RBP: 0000000000040aff R08: ffffffff843c60d7 R09: 0000000000000000
R10: 0000000000000000 R11: ffff88811c2c83c8 R12: ffff88810b9e4770
R13: ffff88810b9e4770 R14: ffff88810b9e3b80 R15: 0000000000000002
FS:  0000555572dd2500(0000) GS:ffff8882a9226000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 00007f9f01dea2f8 CR3: 0000000116262000 CR4: 00000000000006f0
Call Trace:
 <TASK>
 lock_acquire+0x106/0x350
 down_write+0x96/0x200
 f2fs_write_checkpoint+0x677/0x2710
 kill_f2fs_super+0x2f6/0x700
 deactivate_locked_super+0xbc/0x130
 cleanup_mnt+0x3d3/0x460
 task_work_run+0x1d9/0x270
 exit_to_user_mode_loop+0x1fa/0x730
 do_syscall_64+0x353/0x580
 entry_SYSCALL_64_after_hwframe+0x77/0x7f
RIP: 0033:0x7f37e879e097
Code: a2 c7 05 5c 06 25 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:00007ffd156b77b8 EFLAGS: 00000246 ORIG_RAX: 00000000000000a6
RAX: 0000000000000000 RBX: 00007f37e88322ca RCX: 00007f37e879e097
RDX: 0000000000000000 RSI: 0000000000000009 RDI: 00007ffd156b7870
RBP: 00007ffd156b7870 R08: 00007ffd156b8870 R09: 00000000ffffffff
R10: 0000000000000000 R11: 0000000000000246 R12: 00007ffd156b8900
R13: 00007f37e88322ca R14: 000000000011d638 R15: 00007ffd156b8940
 </TASK>
