INFO: task syz.6.663:11204 blocked for more than 143 seconds.
      Not tainted syzkaller #0
"echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message.
task:syz.6.663       state:D stack:24696 pid:11204 tgid:11203 ppid:10997  task_flags:0x400140 flags:0x00080002
Call Trace:
 <TASK>
 __schedule+0x14bc/0x5000
 schedule+0x165/0x360
 schedule_preempt_disabled+0x13/0x30
 rwsem_down_read_slowpath+0x5fd/0x8f0
 down_read+0x99/0x2e0
 super_lock+0x2a9/0x3b0
 __iterate_supers+0x126/0x290
 ksys_sync+0x94/0x150
 __ia32_sys_sync+0xe/0x20
 do_syscall_64+0xfa/0xf80
 entry_SYSCALL_64_after_hwframe+0x77/0x7f
RIP: 0033:0x7fdc6458f7c9
RSP: 002b:00007fdc65485038 EFLAGS: 00000246 ORIG_RAX: 00000000000000a2
RAX: ffffffffffffffda RBX: 00007fdc647e5fa0 RCX: 00007fdc6458f7c9
RDX: 0000000000000000 RSI: 0000000000000000 RDI: 0000000000000000
RBP: 00007fdc647e5fa0 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000
R13: 00007fdc647e6038 R14: 00007fdc647e5fa0 R15: 00007ffdc1717ab8
 </TASK>
INFO: task syz.7.668:11266 blocked for more than 143 seconds.
      Not tainted syzkaller #0
"echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message.
task:syz.7.668       state:D stack:24856 pid:11266 tgid:11265 ppid:10985  task_flags:0x400140 flags:0x00080002
Call Trace:
 <TASK>
 __schedule+0x14bc/0x5000
 schedule+0x165/0x360
 schedule_preempt_disabled+0x13/0x30
 rwsem_down_read_slowpath+0x5fd/0x8f0
 down_read+0x99/0x2e0
 super_lock+0x2a9/0x3b0
 __iterate_supers+0x126/0x290
 ksys_sync+0x94/0x150
 __ia32_sys_sync+0xe/0x20
 do_syscall_64+0xfa/0xf80
 entry_SYSCALL_64_after_hwframe+0x77/0x7f
RIP: 0033:0x7f293e78f7c9
RSP: 002b:00007f293f63f038 EFLAGS: 00000246 ORIG_RAX: 00000000000000a2
RAX: ffffffffffffffda RBX: 00007f293e9e5fa0 RCX: 00007f293e78f7c9
RDX: 0000000000000000 RSI: 0000000000000000 RDI: 0000000000000000
RBP: 00007f293e9e5fa0 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000
R13: 00007f293e9e6038 R14: 00007f293e9e5fa0 R15: 00007fffdf4f6f38
 </TASK>
INFO: task syz.9.671:11385 blocked for more than 143 seconds.
      Not tainted syzkaller #0
"echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message.
task:syz.9.671       state:D stack:24856 pid:11385 tgid:11383 ppid:11284  task_flags:0x400140 flags:0x00080002
Call Trace:
 <TASK>
 __schedule+0x14bc/0x5000
 schedule+0x165/0x360
 schedule_preempt_disabled+0x13/0x30
 rwsem_down_read_slowpath+0x5fd/0x8f0
 down_read+0x99/0x2e0
 super_lock+0x2a9/0x3b0
 __iterate_supers+0x126/0x290
 __se_sys_quotactl+0x353/0x950
 do_syscall_64+0xfa/0xf80
 entry_SYSCALL_64_after_hwframe+0x77/0x7f
RIP: 0033:0x7f7c0718f7c9
RSP: 002b:00007f7c07f46038 EFLAGS: 00000246 ORIG_RAX: 00000000000000b3
RAX: ffffffffffffffda RBX: 00007f7c073e5fa0 RCX: 00007f7c0718f7c9
RDX: 0000000000000000 RSI: 0000000000000000 RDI: ffffffff80000100
RBP: 00007f7c071f297f R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000
R13: 00007f7c073e6038 R14: 00007f7c073e5fa0 R15: 00007ffecdabfda8
 </TASK>

Showing all locks held in the system:
1 lock held by khungtaskd/35:
 #0: ffffffff8df419e0 (rcu_read_lock){....}-{1:3}, at: debug_show_all_locks+0x2e/0x180
2 locks held by getty/5661:
 #0: ffff8881754130a0 (&tty->ldisc_sem){++++}-{0:0}, at: tty_ldisc_ref_wait+0x25/0x70
 #1: ffffc9000356b2f0 (&ldata->atomic_read_lock){+.+.}-{4:4}, at: n_tty_read+0x449/0x1460
2 locks held by syz-executor/10309:
1 lock held by syz.6.663/11204:
 #0: ffff8881152040e0 (&type->s_umount_key#84){++++}-{4:4}, at: super_lock+0x2a9/0x3b0
1 lock held by syz.7.668/11266:
 #0: ffff8881152040e0 (&type->s_umount_key#84){++++}-{4:4}, at: super_lock+0x2a9/0x3b0
1 lock held by syz.9.671/11385:
 #0: ffff8881152040e0 (&type->s_umount_key#84){++++}-{4:4}, at: super_lock+0x2a9/0x3b0
1 lock held by syz.0.680/11635:
 #0: ffff8881152040e0 (&type->s_umount_key#84){++++}-{4:4}, at: super_lock+0x2a9/0x3b0
1 lock held by syz.8.679/11637:
 #0: ffff8881152040e0 (&type->s_umount_key#84){++++}-{4:4}, at: super_lock+0x2a9/0x3b0
2 locks held by syz.8.679/11646:
 #0: ffff8881a8dca420 (sb_writers#3){.+.+}-{0:0}, at: direct_splice_actor+0x49/0x160
 #1: ffff8881152040e0 (&type->s_umount_key#84){++++}-{4:4}, at: super_lock+0x2a9/0x3b0
1 lock held by syz.4.683/11765:
 #0: ffff8881152040e0 (&type->s_umount_key#84){++++}-{4:4}, at: super_lock+0x2a9/0x3b0
1 lock held by syz.3.684/11866:
 #0: ffff8881152040e0 (&type->s_umount_key#84){++++}-{4:4}, at: super_lock+0x2a9/0x3b0
1 lock held by syz.2.692/11958:
 #0: ffff8881152040e0 (&type->s_umount_key#84){++++}-{4:4}, at: super_lock+0x2a9/0x3b0
1 lock held by syz.1.694/12018:
 #0: ffff8881152040e0 (&type->s_umount_key#84){++++}-{4:4}, at: super_lock+0x2a9/0x3b0
1 lock held by syz.5.695/12099:
 #0: ffff8881152040e0 (&type->s_umount_key#84){++++}-{4:4}, at: super_lock+0x2a9/0x3b0
2 locks held by syz.7.697/12165:
 #0: ffff8880300b4420 (sb_writers#3){.+.+}-{0:0}, at: direct_splice_actor+0x49/0x160
 #1: ffff8881152040e0 (&type->s_umount_key#84){++++}-{4:4}, at: super_lock+0x2a9/0x3b0
1 lock held by syz.6.709/12181:
 #0: ffff8881152040e0 (&type->s_umount_key#84){++++}-{4:4}, at: super_lock+0x2a9/0x3b0
1 lock held by syz.9.710/12213:
 #0: ffff8881152040e0 (&type->s_umount_key#84){++++}-{4:4}, at: super_lock+0x2a9/0x3b0
1 lock held by syz.8.713/12251:
 #0: ffff8881152040e0 (&type->s_umount_key#84){++++}-{4:4}, at: super_lock+0x2a9/0x3b0
1 lock held by syz.0.715/12277:
 #0: ffff8881152040e0 (&type->s_umount_key#84){++++}-{4:4}, at: super_lock+0x2a9/0x3b0
1 lock held by syz.0.715/12278:
 #0: ffff8881152040e0 (&type->s_umount_key#84){++++}-{4:4}, at: super_lock+0x2a9/0x3b0
1 lock held by syz.4.720/12325:
 #0: ffff8881152040e0 (&type->s_umount_key#84){++++}-{4:4}, at: super_lock+0x2a9/0x3b0
1 lock held by syz.3.723/12352:
 #0: ffff8881152040e0 (&type->s_umount_key#84){++++}-{4:4}, at: super_lock+0x2a9/0x3b0
1 lock held by syz.2.724/12376:
 #0: ffff8881152040e0 (&type->s_umount_key#84){++++}-{4:4}, at: super_lock+0x2a9/0x3b0
1 lock held by syz.1.736/12458:
 #0: ffff8881152040e0 (&type->s_umount_key#84){++++}-{4:4}, at: super_lock+0x2a9/0x3b0
1 lock held by syz.5.730/12460:
 #0: ffff8881152040e0 (&type->s_umount_key#84){++++}-{4:4}, at: super_lock+0x2a9/0x3b0
1 lock held by syz.7.737/12490:
 #0: ffff8881152040e0 (&type->s_umount_key#84){++++}-{4:4}, at: super_lock+0x2a9/0x3b0
1 lock held by syz.9.743/12567:
 #0: ffff8881152040e0 (&type->s_umount_key#84){++++}-{4:4}, at: super_lock+0x2a9/0x3b0
1 lock held by syz.6.746/12576:
 #0: ffff8881152040e0 (&type->s_umount_key#84){++++}-{4:4}, at: super_lock+0x2a9/0x3b0
4 locks held by kworker/u10:32/12617:
 #0: ffff888100089948 ((wq_completion)events_unbound#2){+.+.}-{0:0}, at: process_scheduled_works+0x9b4/0x1770
 #1: ffffc90022b17b80 ((linkwatch_work).work){+.+.}-{0:0}, at: process_scheduled_works+0x9ef/0x1770
 #2: ffffffff8f30f948 (rtnl_mutex){+.+.}-{4:4}, at: linkwatch_event+0xe/0x60
 #3: ffffffff8df47538 (rcu_state.exp_mutex){+.+.}-{4:4}, at: synchronize_rcu_expedited+0x3b9/0x730
1 lock held by syz.8.761/12643:
 #0: ffff8881152040e0 (&type->s_umount_key#84){++++}-{4:4}, at: super_lock+0x2a9/0x3b0
1 lock held by syz.8.761/12644:
 #0: ffff8881152040e0 (&type->s_umount_key#84){++++}-{4:4}, at: super_lock+0x2a9/0x3b0
5 locks held by syz-executor/12647:
 #0: ffff888173bc8ec0 (&hdev->req_lock){+.+.}-{4:4}, at: hci_unregister_dev+0x212/0x5b0
 #1: ffff888173bc80c0 (&hdev->lock){+.+.}-{4:4}, at: hci_dev_close_sync+0x640/0x1100
 #2: ffffffff8f4813c8 (hci_cb_list_lock){+.+.}-{4:4}, at: hci_conn_hash_flush+0xa1/0x260
 #3: ffff88811ee6db38 (&conn->lock#2){+.+.}-{4:4}, at: l2cap_conn_del+0x7b/0x5b0
 #4: ffffffff8df47538 (rcu_state.exp_mutex){+.+.}-{4:4}, at: synchronize_rcu_expedited+0x2f6/0x730

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

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+0x189/0x250
 nmi_cpu_backtrace+0x39e/0x3d0
 nmi_trigger_cpumask_backtrace+0x17a/0x300
 sys_info+0x135/0x170
 watchdog+0xf95/0xfe0
 kthread+0x711/0x8a0
 ret_from_fork+0x599/0xb30
 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: 10309 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:do_raw_spin_lock+0x12e/0x290
Code: 00 48 89 df be 04 00 00 00 e8 9e eb 88 00 48 8d 7c 24 40 be 04 00 00 00 e8 8f eb 88 00 8b 44 24 40 b9 01 00 00 00 f0 0f b1 0b <0f> 85 dd 00 00 00 65 8b 1d 49 46 df 10 48 b9 00 00 00 00 00 fc ff
RSP: 0018:ffffc90005e07540 EFLAGS: 00000246
RAX: 0000000000000000 RBX: ffff888117a6da80 RCX: 0000000000000001
RDX: 0000000000000001 RSI: 0000000000000004 RDI: ffffc90005e07580
RBP: ffffc90005e075e8 R08: 0000000000000003 R09: 0000000000000004
R10: dffffc0000000000 R11: fffff52000bc0eb0 R12: ffff888117a6da90
R13: ffff888117a6da88 R14: 1ffff11022f4db52 R15: 1ffff11022f4db51
FS:  0000555591381500(0000) GS:ffff8882a9e3a000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 00007f0fec317d60 CR3: 00000001a7b68000 CR4: 00000000000006f0
Call Trace:
 <TASK>
 writeback_single_inode+0x4ab/0xc70
 sync_inode_metadata+0xb9/0x110
 f2fs_write_checkpoint+0xae9/0x2430
 kill_f2fs_super+0x2d2/0x6c0
 deactivate_locked_super+0xbc/0x130
 cleanup_mnt+0x425/0x4c0
 task_work_run+0x1d4/0x260
 exit_to_user_mode_loop+0xff/0x4f0
 do_syscall_64+0x2e3/0xf80
 entry_SYSCALL_64_after_hwframe+0x77/0x7f
RIP: 0033:0x7f9091d90af7
Code: a8 ff ff ff f7 d8 64 89 01 48 83 c8 ff c3 0f 1f 44 00 00 31 f6 e9 09 00 00 00 66 0f 1f 84 00 00 00 00 00 b8 a6 00 00 00 0f 05 <48> 3d 00 f0 ff ff 77 01 c3 48 c7 c2 a8 ff ff ff f7 d8 64 89 02 b8
RSP: 002b:00007ffd02cabb28 EFLAGS: 00000246 ORIG_RAX: 00000000000000a6
RAX: 0000000000000000 RBX: 00007f9091dee72f RCX: 00007f9091d90af7
RDX: 0000000000000000 RSI: 0000000000000009 RDI: 00007ffd02cabbe0
RBP: 00007ffd02cabbe0 R08: 0000000000000000 R09: 0000000000000000
R10: 00000000ffffffff R11: 0000000000000246 R12: 00007ffd02cacc70
R13: 00007f9091dee72f R14: 0000000000041714 R15: 00007ffd02caccb0
 </TASK>
