INFO: task syz.1.264:8034 blocked for more than 143 seconds.
      Not tainted syzkaller #0
"echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message.
task:syz.1.264       state:D stack:25128 pid:8034  tgid:8033  ppid:7829   task_flags:0x400140 flags:0x00004004
Call Trace:
 <TASK>
 __schedule+0x1798/0x4cc0
 schedule+0x165/0x360
 schedule_preempt_disabled+0x13/0x30
 rwsem_down_write_slowpath+0x872/0xfe0
 down_write+0x1ab/0x1f0
 super_lock+0x25c/0x3b0
 user_get_super+0xc8/0x120
 __se_sys_quotactl+0x4da/0x950
 do_syscall_64+0xfa/0x3b0
 entry_SYSCALL_64_after_hwframe+0x77/0x7f
RIP: 0033:0x7f23f2b8eba9
RSP: 002b:00007f23f39ad038 EFLAGS: 00000246 ORIG_RAX: 00000000000000b3
RAX: ffffffffffffffda RBX: 00007f23f2dd5fa0 RCX: 00007f23f2b8eba9
RDX: 0000000000000000 RSI: 0000200000000200 RDI: ffffffff80000201
RBP: 00007f23f2c11e19 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000
R13: 00007f23f2dd6038 R14: 00007f23f2dd5fa0 R15: 00007ffcac5141c8
 </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
2 locks held by getty/5678:
 #0: ffff8880230250a0 (&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
2 locks held by syz-executor/5852:
2 locks held by syz-executor/6923:
1 lock held by syz.1.264/8034:
 #0: ffff8880362980e0 (&type->s_umount_key#56){++++}-{4:4}, at: super_lock+0x25c/0x3b0
2 locks held by dhcpcd/8952:
 #0: ffff888029ea4408 (&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.1.434/9673:
 #0: ffff8880362980e0 (&type->s_umount_key#56){++++}-{4:4}, at: super_lock+0x2a9/0x3b0
1 lock held by syz.1.434/9675:
 #0: ffff8880362980e0 (&type->s_umount_key#56){++++}-{4:4}, at: super_lock+0x2a9/0x3b0
4 locks held by cmp/10479:

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

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: 10472 Comm: syz.9.504 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+0x50e/0xd20
Code: c7 28 41 89 c4 48 39 cb 0f 8d d6 00 00 00 48 83 fb 31 0f 83 92 00 00 00 41 8b 07 25 ff 1f 00 00 48 0f a3 05 64 fd 0a 12 73 10 <48> 69 c0 c8 00 00 00 48 8d 88 10 73 49 93 eb 40 83 3d cb 8c 0e 18
RSP: 0000:ffffc900045dfa48 EFLAGS: 00000003
RAX: 0000000000000007 RBX: 0000000000000001 RCX: 0000000000000002
RDX: 0000000000000003 RSI: 0000000000000000 RDI: ffff88810b96d640
RBP: 0000000000000000 R08: 0000000000000000 R09: ffffffff82100a5e
R10: ffffc900045dfd0c R11: fffff520008bbfaa R12: 00000000ffffff05
R13: 0000000000000003 R14: ffff88810b96e180 R15: ffff88810b96e178
FS:  00007f2d414486c0(0000) GS:ffff8880b8615000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 00007f2d373f2000 CR3: 0000000043e70000 CR4: 00000000000006f0
Call Trace:
 <TASK>
 lock_acquire+0x120/0x360
 _raw_spin_lock+0x2e/0x40
 __pte_offset_map_lock+0x13e/0x210
 __handle_mm_fault+0x2327/0x5440
 handle_mm_fault+0x40a/0x8e0
 do_user_addr_fault+0xa81/0x1390
 exc_page_fault+0x76/0xf0
 asm_exc_page_fault+0x26/0x30
RIP: 0033:0x7f2d40450c46
Code: f0 72 6e 48 63 cd 48 01 c1 49 39 4f 08 72 4c 8d 4d ff 85 ed 74 33 66 0f 1f 44 00 00 48 39 f0 72 1b 4d 8b 07 49 89 c1 49 29 f1 <47> 0f b6 0c 08 45 84 c9 74 08 45 88 0c 00 49 8b 47 10 48 83 c0 01
RSP: 002b:00007f2d414474a0 EFLAGS: 00010206
RAX: 00000000011f2001 RBX: 00007f2d41447540 RCX: 00000000000000e0
RDX: 0000000000000000 RSI: 0000000000000001 RDI: 00007f2d414475e0
RBP: 0000000000000102 R08: 00007f2d36200000 R09: 00000000011f2000
R10: 0000000000000000 R11: 00007f2d41447550 R12: 0000000000000001
R13: 00007f2d4062da20 R14: 0000000000000000 R15: 00007f2d414475e0
 </TASK>
