INFO: task syz.5.648:11249 blocked for more than 143 seconds.
      Not tainted syzkaller #0
"echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message.
task:syz.5.648       state:D stack:25128 pid:11249 tgid:11248 ppid:11038  task_flags:0x400140 flags:0x00080002
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
 user_get_super+0xc8/0x120
 __se_sys_quotactl+0x4da/0x950
 do_syscall_64+0xfa/0xfa0
 entry_SYSCALL_64_after_hwframe+0x77/0x7f
RIP: 0033:0x7fda2938efc9
RSP: 002b:00007fda2a2f5038 EFLAGS: 00000246 ORIG_RAX: 00000000000000b3
RAX: ffffffffffffffda RBX: 00007fda295e5fa0 RCX: 00007fda2938efc9
RDX: ffffffffffffffff RSI: 0000200000000000 RDI: ffffffff80000802
RBP: 00007fda29411f91 R08: 0000000000000000 R09: 0000000000000000
R10: 0000200000000280 R11: 0000000000000246 R12: 0000000000000000
R13: 00007fda295e6038 R14: 00007fda295e5fa0 R15: 00007ffcc1aa0178
 </TASK>

Showing all locks held in the system:
1 lock held by khungtaskd/34:
 #0: ffffffff8df3d2e0 (rcu_read_lock){....}-{1:3}, at: debug_show_all_locks+0x2e/0x180
2 locks held by getty/5639:
 #0: ffff888113e440a0 (&tty->ldisc_sem){++++}-{0:0}, at: tty_ldisc_ref_wait+0x25/0x70
 #1: ffffc9000356e2f0 (&ldata->atomic_read_lock){+.+.}-{4:4}, at: n_tty_read+0x43e/0x1400
2 locks held by syz-executor/6849:
1 lock held by syz.5.648/11249:
 #0: ffff8881b82a20e0 (&type->s_umount_key#63){++++}-{4:4}, at: super_lock+0x2a9/0x3b0
1 lock held by syz.4.948/13659:
 #0: ffff8881b82a20e0 (&type->s_umount_key#63){++++}-{4:4}, at: super_lock+0x2a9/0x3b0
2 locks held by syz.5.1037/14393:
3 locks held by syz.8.1032/14401:
2 locks held by syz.7.1040/14432:

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

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+0x189/0x250
 nmi_cpu_backtrace+0x39e/0x3d0
 nmi_trigger_cpumask_backtrace+0x17a/0x300
 watchdog+0xf60/0xfa0
 kthread+0x711/0x8a0
 ret_from_fork+0x4bc/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: 14432 Comm: syz.7.1040 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:mark_lock+0xa0/0x190
Code: c7 c7 bb 18 8f 8d 48 c7 c6 db b3 7e 8d e8 d8 9d e5 ff 90 0f 0b 90 90 90 31 c9 4c 89 fe 4c 89 f7 b8 01 00 00 00 85 69 60 74 10 <5b> 41 5c 41 5d 41 5e 41 5f 5d e9 d1 71 ab 09 cc 49 89 fe 49 89 f7
RSP: 0018:ffffc900052969e8 EFLAGS: 00000006
RAX: 0000000000000001 RBX: 0000000000000008 RCX: ffffffff9316dd58
RDX: 0000000000000008 RSI: ffff88810b790ba8 RDI: ffff88810b790000
RBP: 0000000000000100 R08: 0000000000000000 R09: ffffffff81a05089
R10: dffffc0000000000 R11: fffffbfff1bba650 R12: 0000000000000004
R13: 0000000000000002 R14: ffff88810b790ba8 R15: ffff88810b790bc8
FS:  00007f267ba0c6c0(0000) GS:ffff8882a9f3e000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 00007f4be85cdba8 CR3: 0000000112028000 CR4: 00000000000006f0
Call Trace:
 <TASK>
 __lock_acquire+0x6a8/0xd20
 lock_acquire+0x120/0x360
 _raw_spin_lock+0x2e/0x40
 console_flush_all+0x659/0xb10
 console_unlock+0xbb/0x190
 vprintk_emit+0x4c5/0x590
 _printk+0xcf/0x120
 set_capacity_and_notify+0x208/0x2d0
 loop_set_size+0x44/0xb0
 loop_configure+0x9f8/0xe50
 lo_ioctl+0x806/0x1c50
 blkdev_ioctl+0x5af/0x6d0
 __se_sys_ioctl+0xfc/0x170
 do_syscall_64+0xfa/0xfa0
 entry_SYSCALL_64_after_hwframe+0x77/0x7f
RIP: 0033:0x7f267ab8ebcb
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:00007f267ba0bdc0 EFLAGS: 00000246 ORIG_RAX: 0000000000000010
RAX: ffffffffffffffda RBX: 0000000000000004 RCX: 00007f267ab8ebcb
RDX: 0000000000000003 RSI: 0000000000004c00 RDI: 0000000000000004
RBP: 0000000000000000 R08: 0000000000000000 R09: 0000000000009862
R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000003
R13: 00007f267ba0bef0 R14: 00007f267ba0beb0 R15: 00007f2670800000
 </TASK>
