INFO: task syz.6.573:10323 blocked for more than 143 seconds.
      Not tainted syzkaller #0
"echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message.
task:syz.6.573       state:D stack:27496 pid:10323 tgid:10322 ppid:9996   task_flags:0x400140 flags:0x00080002
Call Trace:
 <TASK>
 __schedule+0x15dd/0x52d0
 schedule+0x164/0x360
 schedule_preempt_disabled+0x13/0x30
 rwsem_down_read_slowpath+0x61e/0x920
 down_read+0x99/0x2e0
 super_lock+0x2d6/0x3d0
 __iterate_supers+0x126/0x290
 __se_sys_quotactl+0x3a7/0x9e0
 do_syscall_64+0x14d/0xf80
 entry_SYSCALL_64_after_hwframe+0x77/0x7f
RIP: 0033:0x7f3f0339c799
RSP: 002b:00007f3f042c3028 EFLAGS: 00000246 ORIG_RAX: 00000000000000b3
RAX: ffffffffffffffda RBX: 00007f3f03615fa0 RCX: 00007f3f0339c799
RDX: 0000000000000000 RSI: 0000000000000000 RDI: ffffffff80000102
RBP: 00007f3f03432c99 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000
R13: 00007f3f03616038 R14: 00007f3f03615fa0 R15: 00007ffc76353118
 </TASK>

Showing all locks held in the system:
1 lock held by khungtaskd/34:
 #0: ffffffff8e75e5e0 (rcu_read_lock){....}-{1:3}, at: debug_show_all_locks+0x2e/0x180
2 locks held by getty/5636:
 #0: ffff88810f1f50a0 (&tty->ldisc_sem){++++}-{0:0}, at: tty_ldisc_ref_wait+0x25/0x70
 #1: ffffc9000356b2f0 (&ldata->atomic_read_lock){+.+.}-{4:4}, at: n_tty_read+0x45c/0x13c0
2 locks held by syz-executor/9104:
2 locks held by syz-executor/9410:
2 locks held by syz-executor/9732:
1 lock held by syz.6.573/10323:
 #0: ffff8881badc60e0 (&type->s_umount_key#65){++++}-{4:4}, at: super_lock+0x2d6/0x3d0
2 locks held by syz-executor/11505:
1 lock held by syz.0.845/12087:
 #0: ffff8881badc60e0 (&type->s_umount_key#65){++++}-{4:4}, at: super_lock+0x2d6/0x3d0
1 lock held by syz.1.947/12463:
2 locks held by syz.2.951/12471:

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

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/0x300
 sys_info+0x135/0x170
 watchdog+0xfd9/0x1030
 kthread+0x388/0x470
 ret_from_fork+0x51e/0xb90
 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: 12465 Comm: syz.6.948 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:__sanitizer_cov_trace_pc+0x36/0x70
Code: c8 8d 56 11 65 8b 15 e9 8d 56 11 81 e2 00 01 ff 00 74 11 81 fa 00 01 00 00 75 35 83 b9 a4 16 00 00 00 74 2c 8b 91 80 16 00 00 <83> fa 02 75 21 48 8b 91 88 16 00 00 48 8b 32 48 8d 7e 01 8b 89 84
RSP: 0000:ffffc90006b7fa68 EFLAGS: 00000246
RAX: ffffffff823c3eec RBX: ffffffff823c3eaa RCX: ffff88816eaa0000
RDX: 0000000000000002 RSI: ffffffff8c27c8e0 RDI: ffffffff8c27c8a0
RBP: 0000000000000001 R08: ffffffff823c3eaa R09: ffffffff8e75e6a0
R10: dffffc0000000000 R11: ffffed102ea188f1 R12: dffffc0000000000
R13: ffff8881750c3d40 R14: 0000000000013204 R15: ffff88814fef3040
FS:  00007fa701df96c0(0000) GS:ffff8882a945d000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 00007fa6f7998000 CR3: 0000000194570000 CR4: 00000000000006f0
Call Trace:
 <TASK>
 pfn_valid+0xfc/0x480
 page_table_check_set+0x25/0x610
 set_ptes+0x233/0x240
 do_pte_missing+0x2ba0/0x3490
 handle_mm_fault+0x1bec/0x3310
 do_user_addr_fault+0xa73/0x1340
 exc_page_fault+0x6a/0xc0
 asm_exc_page_fault+0x26/0x30
RIP: 0033:0x7fa700e53b0e
Code: c1 49 39 4f 08 72 54 8d 4d ff 85 ed 74 3b 66 66 2e 0f 1f 84 00 00 00 00 00 0f 1f 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:00007fa701df8470 EFLAGS: 00010206
RAX: 0000000000d98001 RBX: 00007fa701df8530 RCX: 0000000000000070
RDX: 0000000000000000 RSI: 0000000000000001 RDI: 00007fa701df85d0
RBP: 0000000000000102 R08: 00007fa6f6c00000 R09: 0000000000d98000
R10: 0000000000000000 R11: 00007fa701df8540 R12: 0000000000000001
R13: 00007fa701052620 R14: 0000000000000000 R15: 00007fa701df85d0
 </TASK>
