INFO: task syz.4.214:7680 blocked for more than 143 seconds.
      Not tainted syzkaller #0
"echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message.
task:syz.4.214       state:D stack:24856 pid:7680  tgid:7679  ppid:7410   task_flags:0x400040 flags:0x00080002
Call Trace:
 <TASK>
 __schedule+0x14ef/0x4fb0
 schedule+0x164/0x360
 schedule_preempt_disabled+0x13/0x30
 rwsem_down_read_slowpath+0x61e/0x920
 down_read+0x99/0x2e0
 super_lock+0x2d6/0x3d0
 user_get_super+0xc8/0x120
 __se_sys_quotactl+0x516/0x990
 do_syscall_64+0xe2/0xf80
 entry_SYSCALL_64_after_hwframe+0x77/0x7f
RIP: 0033:0x7f94cb99acb9
RSP: 002b:00007f94cc923028 EFLAGS: 00000246 ORIG_RAX: 00000000000000b3
RAX: ffffffffffffffda RBX: 00007f94cbc15fa0 RCX: 00007f94cb99acb9
RDX: 0000000000000000 RSI: 0000200000000340 RDI: ffffffff80000800
RBP: 00007f94cba08bf7 R08: 0000000000000000 R09: 0000000000000000
R10: 0000200000000080 R11: 0000000000000246 R12: 0000000000000000
R13: 00007f94cbc16038 R14: 00007f94cbc15fa0 R15: 00007fffeee9e628
 </TASK>

Showing all locks held in the system:
1 lock held by khungtaskd/35:
 #0: ffffffff8e341b60 (rcu_read_lock){....}-{1:3}, at: debug_show_all_locks+0x2e/0x180
2 locks held by getty/5657:
 #0: ffff88811266d0a0 (&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
4 locks held by kworker/u8:2/5700:
 #0: ffff888100ef7948 ((wq_completion)netns){+.+.}-{0:0}, at: process_scheduled_works+0x9d4/0x17a0
 #1: ffffc900042c7bc0 (net_cleanup_work){+.+.}-{0:0}, at: process_scheduled_works+0xa0f/0x17a0
 #2: ffffffff8e347580 (rcu_state.barrier_mutex){+.+.}-{4:4}, at: rcu_barrier+0x4c/0x580
 #3: ffff88812103a918 (&rq->__lock){-.-.}-{2:2}, at: raw_spin_rq_lock_nested+0x2a/0x140
3 locks held by syz-executor/6377:
3 locks held by kworker/1:7/7228:
 #0: ffff888100075948 ((wq_completion)events){+.+.}-{0:0}, at: process_scheduled_works+0x9d4/0x17a0
 #1: ffffc900046c7bc0 (free_ipc_work){+.+.}-{0:0}, at: process_scheduled_works+0xa0f/0x17a0
 #2: ffffffff8e3476b8 (rcu_state.exp_mutex){+.+.}-{4:4}, at: synchronize_rcu_expedited+0x2d0/0x770
1 lock held by syz.4.214/7680:
 #0: ffff8881032c40e0 (&type->s_umount_key#53){++++}-{4:4}, at: super_lock+0x2d6/0x3d0
2 locks held by syz-executor/9127:
1 lock held by syz.4.467/10441:
 #0: ffff8881032c40e0 (&type->s_umount_key#53){++++}-{4:4}, at: super_lock+0x2d6/0x3d0
1 lock held by syz-executor/11298:
1 lock held by syz-executor/11414:
1 lock held by syz-executor/11423:

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

NMI backtrace for cpu 0
CPU: 0 UID: 0 PID: 35 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+0xf90/0xfe0
 kthread+0x726/0x8b0
 ret_from_fork+0x51b/0xa40
 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: 11414 Comm: syz-executor 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:kasan_check_range+0xd/0x2c0
Code: e9 86 fe fe 90 0f 0b cc cc cc cc cc cc 90 90 90 90 90 90 90 90 90 90 90 90 90 90 90 90 0f 1f 40 d6 55 41 57 41 56 41 55 41 54 <53> b0 01 48 85 f6 0f 84 ae 01 00 00 4c 8d 04 37 49 39 f8 0f 82 36
RSP: 0018:ffffc900054177f0 EFLAGS: 00000246
RAX: f3f3f3f8f1f1f1f1 RBX: ffff88823c640e40 RCX: ffffffff819fc0a0
RDX: 0000000000000000 RSI: 0000000000000004 RDI: ffff88823c640e40
RBP: ffffc900054178b0 R08: dffffc0000000000 R09: 0000000000000000
R10: ffffed10338ff800 R11: fffffbfff1f84ccf R12: 1ffff92000a82f04
R13: ffff88823c640e40 R14: ffff88823c640e40 R15: dffffc0000000000
FS:  000055557f0ad500(0000) GS:ffff8882a9a08000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 000055a1b3e42a18 CR3: 000000010b10a000 CR4: 00000000000006f0
Call Trace:
 <TASK>
 do_raw_spin_trylock+0x70/0x190
 _raw_spin_trylock+0x21/0x80
 __free_frozen_pages+0x65a/0xd10
 vfree+0x25a/0x400
 kcov_close+0x28/0x50
 __fput+0x44f/0xa70
 task_work_run+0x1d9/0x270
 do_exit+0x69b/0x2310
 do_group_exit+0x21b/0x2d0
 get_signal+0x1284/0x1330
 arch_do_signal_or_restart+0xbc/0x830
 exit_to_user_mode_loop+0x86/0x480
 do_syscall_64+0x2b7/0xf80
 entry_SYSCALL_64_after_hwframe+0x77/0x7f
RIP: 0033:0x7fbd3f35b58e
Code: Unable to access opcode bytes at 0x7fbd3f35b564.
RSP: 002b:00007ffcf97abd68 EFLAGS: 00000246 ORIG_RAX: 000000000000002c
RAX: 0000000000000028 RBX: 000055557f0ad500 RCX: 00007fbd3f35b58e
RDX: 0000000000000028 RSI: 00007fbd40144670 RDI: 0000000000000003
RBP: 0000000000000001 R08: 00007ffcf97abde4 R09: 000000000000000c
R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000003
R13: 0000000000000000 R14: 00007fbd40144670 R15: 0000000000000000
 </TASK>
