INFO: task syz-executor:19538 blocked for more than 143 seconds.
      Not tainted syzkaller #0
"echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message.
task:syz-executor    state:D stack:17448 pid:19538 tgid:19538 ppid:1      task_flags:0x400140 flags:0x00004004
Call Trace:
 <TASK>
 __schedule+0x1798/0x4cc0
 schedule+0x165/0x360
 v9fs_evict_inode+0x170/0x320
 evict+0x504/0x9c0
 __dentry_kill+0x209/0x660
 dput+0x19f/0x2b0
 shrink_dcache_for_umount+0xa0/0x170
 generic_shutdown_super+0x67/0x2c0
 kill_anon_super+0x3b/0x70
 v9fs_kill_super+0x4c/0x90
 deactivate_locked_super+0xbc/0x130
 cleanup_mnt+0x425/0x4c0
 task_work_run+0x1d4/0x260
 exit_to_user_mode_loop+0xec/0x110
 do_syscall_64+0x2bd/0x3b0
 entry_SYSCALL_64_after_hwframe+0x77/0x7f
RIP: 0033:0x7fe4a118ff17
RSP: 002b:00007ffcf6e9c938 EFLAGS: 00000246 ORIG_RAX: 00000000000000a6
RAX: 0000000000000000 RBX: 00007fe4a1211c05 RCX: 00007fe4a118ff17
RDX: 0000000000000000 RSI: 0000000000000009 RDI: 00007ffcf6e9c9f0
RBP: 00007ffcf6e9c9f0 R08: 0000000000000000 R09: 0000000000000000
R10: 00000000ffffffff R11: 0000000000000246 R12: 00007ffcf6e9da80
R13: 00007fe4a1211c05 R14: 00000000000d25b1 R15: 00007ffcf6e9dac0
 </TASK>
INFO: task syz.9.5880:23151 blocked for more than 143 seconds.
      Not tainted syzkaller #0
"echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message.
task:syz.9.5880      state:D stack:23440 pid:23151 tgid:23150 ppid:19075  task_flags:0x400140 flags:0x00004004
Call Trace:
 <TASK>
 __schedule+0x1798/0x4cc0
 schedule+0x165/0x360
 schedule_preempt_disabled+0x13/0x30
 rwsem_down_read_slowpath+0x5fd/0x8f0
 down_read+0x98/0x2e0
 super_lock+0x2a9/0x3b0
 __iterate_supers+0x126/0x290
 ksys_sync+0x94/0x150
 __ia32_sys_sync+0xe/0x20
 do_syscall_64+0xfa/0x3b0
 entry_SYSCALL_64_after_hwframe+0x77/0x7f
RIP: 0033:0x7fba2078ebe9
RSP: 002b:00007fba1e9f6038 EFLAGS: 00000246 ORIG_RAX: 00000000000000a2
RAX: ffffffffffffffda RBX: 00007fba209c5fa0 RCX: 00007fba2078ebe9
RDX: 0000000000000000 RSI: 0000000000000000 RDI: 0000000000000000
RBP: 00007fba209c5fa0 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000
R13: 00007fba209c6038 R14: 00007fba209c5fa0 R15: 00007ffeb1099898
 </TASK>

Showing all locks held in the system:
1 lock held by khungtaskd/34:
 #0: ffffffff8e139f20 (rcu_read_lock){....}-{1:3}, at: debug_show_all_locks+0x2e/0x180
2 locks held by getty/5681:
 #0: ffff888022bd90a0 (&tty->ldisc_sem){++++}-{0:0}, at: tty_ldisc_ref_wait+0x25/0x70
 #1: ffffc900029062f0 (&ldata->atomic_read_lock){+.+.}-{4:4}, at: n_tty_read+0x43e/0x1400
3 locks held by kworker/u11:0/19077:
 #0: ffff888111b9d148 ((wq_completion)hci5){+.+.}-{0:0}, at: process_scheduled_works+0x9b4/0x17b0
 #1: ffffc900064afbc0 ((work_completion)(&hdev->cmd_sync_work)){+.+.}-{0:0}, at: process_scheduled_works+0x9ef/0x17b0
 #2: ffff888121e94dc0 (&hdev->req_lock){+.+.}-{4:4}, at: hci_cmd_sync_work+0x1d4/0x3a0
1 lock held by syz-executor/19538:
 #0: ffff88812bb580e0 (&type->s_umount_key#100){++++}-{4:4}, at: deactivate_super+0xa9/0xe0
1 lock held by syz.9.5880/23151:
 #0: ffff88812bb580e0 (&type->s_umount_key#100){++++}-{4:4}, at: super_lock+0x2a9/0x3b0
1 lock held by syz.6.5916/23254:
 #0: ffff88812bb580e0 (&type->s_umount_key#100){++++}-{4:4}, at: super_lock+0x2a9/0x3b0
1 lock held by syz.6.5916/23255:
 #0: ffff88812bb580e0 (&type->s_umount_key#100){++++}-{4:4}, at: super_lock+0x2a9/0x3b0
1 lock held by syz.6.5916/23256:
 #0: ffff88812bb580e0 (&type->s_umount_key#100){++++}-{4:4}, at: super_lock+0x2a9/0x3b0
1 lock held by syz.6.5916/23257:
 #0: ffff88812bb580e0 (&type->s_umount_key#100){++++}-{4:4}, at: super_lock+0x2a9/0x3b0
1 lock held by syz.6.5916/23258:
 #0: ffff88812bb580e0 (&type->s_umount_key#100){++++}-{4:4}, at: super_lock+0x2a9/0x3b0
1 lock held by syz.6.5916/23259:
 #0: ffff88812bb580e0 (&type->s_umount_key#100){++++}-{4:4}, at: super_lock+0x2a9/0x3b0
1 lock held by syz.1.6525/24829:
 #0: ffffffff8e13f880 (rcu_state.barrier_mutex){+.+.}-{4:4}, at: rcu_barrier+0x4c/0x570
1 lock held by syz.0.6874/25611:
1 lock held by syz.4.6964/25803:
 #0: ffff88812bb580e0 (&type->s_umount_key#100){++++}-{4:4}, at: super_lock+0x2a9/0x3b0
5 locks held by syz-executor/26190:
 #0: ffff88812d1b0dc0 (&hdev->req_lock){+.+.}-{4:4}, at: hci_unregister_dev+0x212/0x510
 #1: ffff88812d1b00b8 (&hdev->lock){+.+.}-{4:4}, at: hci_dev_close_sync+0x66a/0x1330
 #2: ffffffff8f69e888 (hci_cb_list_lock){+.+.}-{4:4}, at: hci_conn_hash_flush+0xa1/0x230
 #3: ffff88802cc8bb38 (&conn->lock#2){+.+.}-{4:4}, at: l2cap_conn_del+0x70/0x680
 #4: ffffffff8e13f9b8 (rcu_state.exp_mutex){+.+.}-{4:4}, at: synchronize_rcu_expedited+0x2f6/0x730

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

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+0x3fc/0x770
 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: 24829 Comm: syz.1.6525 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:unwind_next_frame+0x3a6/0x2390
Code: 4c 89 e8 48 c1 e8 03 0f b6 04 28 84 c0 0f 85 80 19 00 00 41 0f b6 44 24 01 83 e0 07 0f 84 75 15 00 00 83 f8 01 4c 8b 7c 24 48 <48> bd 00 00 00 00 00 fc ff df 4c 8b 64 24 20 4c 8b 6c 24 50 0f 84
RSP: 0018:ffffc90008b57538 EFLAGS: 00000202
RAX: 0000000000000002 RBX: ffffffff8fb7eae4 RCX: ffffffff8fb7eae8
RDX: ffffffff90342336 RSI: ffffffff90342336 RDI: ffffffff8be33920
RBP: dffffc0000000000 R08: 0000000000000001 R09: ffffffff8172c195
R10: ffffc90008b57658 R11: ffffffff81ac3ae0 R12: ffffffff9034233a
R13: ffffffff9034233b R14: ffffc90008b57608 R15: ffffffff8172c195
FS:  00007f844ec206c0(0000) GS:ffff8880b8615000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 00007f844eaf7d60 CR3: 000000010f37c000 CR4: 00000000000006f0
Call Trace:
 <TASK>
 arch_stack_walk+0x11c/0x150
 stack_trace_save+0x9c/0xe0
 save_stack+0xf5/0x1f0
 __reset_page_owner+0x71/0x1f0
 __free_frozen_pages+0xbc4/0xd30
 vfree+0x25a/0x400
 kcov_close+0x28/0x50
 __fput+0x44c/0xa70
 task_work_run+0x1d4/0x260
 do_exit+0x6b5/0x2300
 do_group_exit+0x21c/0x2d0
 get_signal+0x1286/0x1340
 arch_do_signal_or_restart+0x9a/0x750
 exit_to_user_mode_loop+0x75/0x110
 do_syscall_64+0x2bd/0x3b0
 entry_SYSCALL_64_after_hwframe+0x77/0x7f
RIP: 0033:0x7f844ddc14a5
Code: Unable to access opcode bytes at 0x7f844ddc147b.
RSP: 002b:00007f844ec1ff80 EFLAGS: 00000293 ORIG_RAX: 00000000000000e6
RAX: fffffffffffffdfc RBX: 00007f844dfc5fa0 RCX: 00007f844ddc14a5
RDX: 00007f844ec1ffc0 RSI: 0000000000000000 RDI: 0000000000000000
RBP: 00007f844de11e19 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000293 R12: 0000000000000000
R13: 00007f844dfc6038 R14: 00007f844dfc5fa0 R15: 00007ffc9c31b2c8
 </TASK>
