INFO: task syz.7.1061:14699 blocked for more than 143 seconds.
      Not tainted syzkaller #0
"echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message.
task:syz.7.1061      state:D stack:28744 pid:14699 tgid:14698 ppid:11784  task_flags:0x400040 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: 0033:0x7f0f64f8ebe9
RSP: 002b:00007f0f65ecb038 EFLAGS: 00000246 ORIG_RAX: 00000000000000a2
RAX: ffffffffffffffda RBX: 00007f0f651b5fa0 RCX: 00007f0f64f8ebe9
RDX: 0000000000000000 RSI: 0000000000000000 RDI: 0000000000000000
RBP: 00007f0f651b5fa0 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000
R13: 00007f0f651b6038 R14: 00007f0f651b5fa0 R15: 00007ffe96fd0fb8
 </TASK>
INFO: task syz.2.1093:14861 blocked for more than 143 seconds.
      Not tainted syzkaller #0
"echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message.
task:syz.2.1093      state:D stack:25128 pid:14861 tgid:14860 ppid:14392  task_flags:0x400040 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
 user_get_super+0xc8/0x120
 __se_sys_quotactl+0x4da/0x950
 do_syscall_64+0xfa/0x3b0
 entry_SYSCALL_64_after_hwframe+0x77/0x7f
RIP: 0033:0x7f6454d8ebe9
RSP: 002b:00007f6455bc0038 EFLAGS: 00000246 ORIG_RAX: 00000000000000b3
RAX: ffffffffffffffda RBX: 00007f6454fb5fa0 RCX: 00007f6454d8ebe9
RDX: 0000000000000000 RSI: 0000200000000080 RDI: ffffffff80000801
RBP: 00007f6454e11e19 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000
R13: 00007f6454fb6038 R14: 00007f6454fb5fa0 R15: 00007ffc1eb88038
 </TASK>

Showing all locks held in the system:
1 lock held by pool_workqueue_/3:
 #0: ffffffff8e13f978 (rcu_state.exp_mutex){+.+.}-{4:4}, at: synchronize_rcu_expedited+0x3b9/0x730
1 lock held by khungtaskd/34:
 #0: ffffffff8e139ee0 (rcu_read_lock){....}-{1:3}, at: debug_show_all_locks+0x2e/0x180
2 locks held by getty/5674:
 #0: ffff888022e9b0a0 (&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
3 locks held by syz-executor/10936:
1 lock held by udevd/13275:
1 lock held by syz.7.1061/14699:
 #0: ffff8880204f80e0 (&type->s_umount_key#61){++++}-{4:4}, at: super_lock+0x2a9/0x3b0
1 lock held by syz.2.1093/14861:
 #0: ffff8880204f80e0 (&type->s_umount_key#61){++++}-{4:4}, at: super_lock+0x2a9/0x3b0
1 lock held by syz.8.1135/15236:
 #0: ffff8880204f80e0 (&type->s_umount_key#61){++++}-{4:4}, at: super_lock+0x2a9/0x3b0
1 lock held by syz.6.1229/16003:
 #0: ffff8880204f80e0 (&type->s_umount_key#61){++++}-{4:4}, at: super_lock+0x2a9/0x3b0
2 locks held by syz.4.1357/17357:
2 locks held by syz.9.1359/17366:

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

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+0xf93/0xfe0
 kthread+0x711/0x8a0
 ret_from_fork+0x3fc/0x770
 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: 17366 Comm: syz.9.1359 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: 0033:0x7fc41826ebe4
Code: 82 b5 03 00 00 c6 44 24 1e 01 45 31 ff 45 31 f6 44 0f b6 e6 85 c0 0f 84 9e 00 00 00 44 89 f9 49 8b 50 40 4c 89 f0 49 03 14 ca <80> 3d bd 91 34 00 00 49 89 d6 48 89 d5 74 28 25 ff 0f 00 00 83 f0
RSP: 002b:00007fff33c01440 EFLAGS: 00000286
RAX: ffffffff8479a1a0 RBX: 00007fc4190e5720 RCX: 0000000000003ff6
RDX: ffffffff8479a1aa RSI: ffffffff8479a1a0 RDI: 0000000000000003
RBP: ffffffff8479a1a0 R08: 00007fc4185b6038 R09: 00007fc4185a2000
R10: 00007fc417dff008 R11: 0000000000000003 R12: 0000000000000003
R13: 0000000000000cdc R14: ffffffff8479a1a0 R15: 0000000000003ff6
FS:  0000555585653500 GS:  0000000000000000
