INFO: task syz.9.674:9847 blocked for more than 143 seconds.
      Not tainted syzkaller #0
"echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message.
task:syz.9.674       state:D stack:25464 pid:9847  tgid:9846  ppid:9453   task_flags:0x400140 flags:0x00080002
Call Trace:
 <TASK>
 __schedule+0x17b4/0x5680
 schedule+0x164/0x360
 schedule_preempt_disabled+0x13/0x30
 rwsem_down_read_slowpath+0x6d9/0x940
 down_read+0x99/0x2e0
 super_lock+0x2d6/0x3d0
 __iterate_supers+0x126/0x250
 __se_sys_quotactl+0x3a7/0x9e0
 do_syscall_64+0x15f/0xf80
 entry_SYSCALL_64_after_hwframe+0x77/0x7f
RIP: 0033:0x7f320a59c819
RSP: 002b:00007f320b477028 EFLAGS: 00000246 ORIG_RAX: 00000000000000b3
RAX: ffffffffffffffda RBX: 00007f320a815fa0 RCX: 00007f320a59c819
RDX: 0000000000000000 RSI: 0000000000000000 RDI: ffffffff80000100
RBP: 00007f320a632c91 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000
R13: 00007f320a816038 R14: 00007f320a815fa0 R15: 00007ffc3aa19bf8
 </TASK>
INFO: task syz.2.681:9879 blocked for more than 143 seconds.
      Not tainted syzkaller #0
"echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message.
task:syz.2.681       state:D stack:25464 pid:9879  tgid:9878  ppid:9488   task_flags:0x400040 flags:0x00080002
Call Trace:
 <TASK>
 __schedule+0x17b4/0x5680
 schedule+0x164/0x360
 schedule_preempt_disabled+0x13/0x30
 rwsem_down_read_slowpath+0x6d9/0x940
 down_read+0x99/0x2e0
 super_lock+0x2d6/0x3d0
 user_get_super+0xc8/0x120
 __se_sys_quotactl+0x540/0x9e0
 do_syscall_64+0x15f/0xf80
 entry_SYSCALL_64_after_hwframe+0x77/0x7f
RIP: 0033:0x7f27cd79c819
RSP: 002b:00007f27ce611028 EFLAGS: 00000246 ORIG_RAX: 00000000000000b3
RAX: ffffffffffffffda RBX: 00007f27cda15fa0 RCX: 00007f27cd79c819
RDX: 0000000000000000 RSI: 00002000000003c0 RDI: ffffffff80000800
RBP: 00007f27cd832c91 R08: 0000000000000000 R09: 0000000000000000
R10: 0000200000000280 R11: 0000000000000246 R12: 0000000000000000
R13: 00007f27cda16038 R14: 00007f27cda15fa0 R15: 00007ffeff75fff8
 </TASK>

Showing all locks held in the system:
1 lock held by khungtaskd/34:
 #0: ffffffff8e95cce0 (rcu_read_lock){....}-{1:3}, at: debug_show_all_locks+0x2e/0x180
2 locks held by getty/5652:
 #0: ffff88811133e0a0 (&tty->ldisc_sem){++++}-{0:0}, at: tty_ldisc_ref_wait+0x25/0x70
 #1: ffffc9000346e2e8 (&ldata->atomic_read_lock){+.+.}-{4:4}, at: n_tty_read+0x45c/0x13a0
3 locks held by syz-executor/5827:
1 lock held by syz.9.674/9847:
 #0: ffff88810fbc00d8 (&type->s_umount_key#57){++++}-{4:4}, at: super_lock+0x2d6/0x3d0
1 lock held by syz.2.681/9879:
 #0: ffff88810fbc00d8 (&type->s_umount_key#57){++++}-{4:4}, at: super_lock+0x2d6/0x3d0
1 lock held by syz.4.837/11306:
 #0: ffff88810fbc00d8 (&type->s_umount_key#57){++++}-{4:4}, at: super_lock+0x2d6/0x3d0
1 lock held by syz.9.1032/12829:
 #0: ffffffff8e962fe8 (rcu_state.exp_mutex){+.+.}-{4:4}, at: synchronize_rcu_expedited+0x2d0/0x770
2 locks held by syz.7.1033/12831:

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

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+0xfd3/0x1030
 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: 12831 Comm: syz.7.1033 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:its_return_thunk+0x0/0x10
Code: cc cc cc cc cc cc cc cc cc cc cc cc cc cc cc cc cc cc cc cc cc cc cc cc cc cc cc cc cc cc cc cc cc cc cc cc cc cc cc cc cc cc <c3> cc 90 90 90 90 90 90 90 90 90 90 90 90 90 90 e9 6b 0a 77 f5 cc
RSP: 0000:ffffc90004337ea0 EFLAGS: 00000097
RAX: ffffffff816c9b7a RBX: 0000000000000000 RCX: ffff88810b2a3b00
RDX: 0000000000000002 RSI: 0000000000000000 RDI: 0000000000000000
RBP: 0000000000000000 R08: ffff88810b2a3b07 R09: 1ffff11021654760
R10: dffffc0000000000 R11: ffffed1021654761 R12: 0000000000000000
R13: 0000000000000000 R14: ffff88810b2a5500 R15: dffffc0000000000
FS:  00007f8e61b806c0(0000) GS:ffff8882a920f000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 00007f8e570f6000 CR3: 0000000175a58000 CR4: 00000000000006f0
Call Trace:
 <TASK>
 fpregs_assert_state_consistent+0x9a/0x150
 arch_exit_to_user_mode_prepare+0xb/0xa0
 irqentry_exit+0x8b/0x730
 asm_exc_page_fault+0x26/0x30
RIP: 0033:0x7f8e60c53b8e
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:00007f8e61b7f470 EFLAGS: 00010206
RAX: 00000000006f6001 RBX: 00007f8e61b7f530 RCX: 000000000000002c
RDX: 0000000000000000 RSI: 0000000000000001 RDI: 00007f8e61b7f5d0
RBP: 0000000000000102 R08: 00007f8e56a00000 R09: 00000000006f6000
R10: 0000000000000000 R11: 00007f8e61b7f540 R12: 0000000000000001
R13: 00007f8e60e52600 R14: 0000000000000000 R15: 00007f8e61b7f5d0
 </TASK>
