INFO: task syz.0.1502:17712 blocked for more than 143 seconds.
      Not tainted syzkaller #0
"echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message.
task:syz.0.1502      state:D stack:28832 pid:17712 tgid:17711 ppid:17252  task_flags:0x400040 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
 __ia32_sys_sync+0xa0/0x120
 do_syscall_64+0x14d/0xf80
 entry_SYSCALL_64_after_hwframe+0x77/0x7f
RIP: 0033:0x7f152159c799
RSP: 002b:00007f15224cb028 EFLAGS: 00000246 ORIG_RAX: 00000000000000a2
RAX: ffffffffffffffda RBX: 00007f1521815fa0 RCX: 00007f152159c799
RDX: 0000000000000000 RSI: 0000000000000000 RDI: 0000000000000000
RBP: 00007f1521815fa0 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000
R13: 00007f1521816038 R14: 00007f1521815fa0 R15: 00007ffff196b6a8
 </TASK>
INFO: task syz.0.1502:17715 blocked for more than 143 seconds.
      Not tainted syzkaller #0
"echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message.
task:syz.0.1502      state:D stack:28832 pid:17715 tgid:17711 ppid:17252  task_flags:0x400040 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
 __ia32_sys_sync+0xa0/0x120
 do_syscall_64+0x14d/0xf80
 entry_SYSCALL_64_after_hwframe+0x77/0x7f
RIP: 0033:0x7f152159c799
RSP: 002b:00007f15224aa028 EFLAGS: 00000246 ORIG_RAX: 00000000000000a2
RAX: ffffffffffffffda RBX: 00007f1521816090 RCX: 00007f152159c799
RDX: 0000000000000000 RSI: 0000000000000000 RDI: 0000000000000000
RBP: 00007f1521816090 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000
R13: 00007f1521816128 R14: 00007f1521816090 R15: 00007ffff196b6a8
 </TASK>

Showing all locks held in the system:
1 lock held by khungtaskd/34:
 #0: ffffffff8e75e520 (rcu_read_lock){....}-{1:3}, at: debug_show_all_locks+0x2e/0x180
2 locks held by getty/5634:
 #0: ffff888114b910a0 (&tty->ldisc_sem){++++}-{0:0}, at: tty_ldisc_ref_wait+0x25/0x70
 #1: ffffc9000356e2f0 (&ldata->atomic_read_lock){+.+.}-{4:4}, at: n_tty_read+0x45c/0x13c0
5 locks held by kworker/u8:2/5704:
 #0: ffff8881012ae148 ((wq_completion)netns){+.+.}-{0:0}, at: process_scheduled_works+0xa52/0x18c0
 #1: ffffc90005e4fc40 (net_cleanup_work){+.+.}-{0:0}, at: process_scheduled_works+0xa8d/0x18c0
 #2: ffffffff8fbbf8b0 (pernet_ops_rwsem){++++}-{4:4}, at: cleanup_net+0xf4/0x800
 #3: ffff88811bc4f0e8 (&dev->mutex){....}-{4:4}, at: devlink_pernet_pre_exit+0x117/0x3f0
 #4: ffff88811bc4c250 (&devlink->lock_key#61){+.+.}-{4:4}, at: devlink_pernet_pre_exit+0x129/0x3f0
3 locks held by syz-executor/15214:
1 lock held by syz.0.1502/17712:
 #0: ffff8881afbe60e0 (&type->s_umount_key#86){++++}-{4:4}, at: super_lock+0x2d6/0x3d0
1 lock held by syz.0.1502/17715:
 #0: ffff8881afbe60e0 (&type->s_umount_key#86){++++}-{4:4}, at: super_lock+0x2d6/0x3d0
1 lock held by syz.7.1589/18603:
 #0: ffff8881afbe60e0 (&type->s_umount_key#86){++++}-{4:4}, at: super_lock+0x289/0x3d0
1 lock held by syz.7.1842/21038:
 #0: ffff8881afbe60e0 (&type->s_umount_key#86){++++}-{4:4}, at: super_lock+0x2d6/0x3d0
5 locks held by syz-executor/22303:
 #0: ffff88811d254ec0 (&hdev->req_lock){+.+.}-{4:4}, at: hci_unregister_dev+0x212/0x5a0
 #1: ffff88811d2540c0 (&hdev->lock){+.+.}-{4:4}, at: hci_dev_close_sync+0x640/0x10e0
 #2: ffffffff8fd5b068 (hci_cb_list_lock){+.+.}-{4:4}, at: hci_conn_hash_flush+0xa1/0x260
 #3: ffff88811aa4b2f8 (&conn->lock#2){+.+.}-{4:4}, at: l2cap_conn_del+0x7b/0x5c0
 #4: ffffffff8e7647b8 (rcu_state.exp_mutex){+.+.}-{4:4}, at: synchronize_rcu_expedited+0x2d0/0x770

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

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: 7571 Comm: kworker/1:6 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
Workqueue: rcu_gp process_srcu
RIP: 0010:filter_irq_stacks+0x5f/0xa0
Code: 89 ff e8 84 14 7f 00 49 8b 04 de 48 3d 30 02 00 81 0f 93 c1 48 3d 90 16 00 81 0f 92 c2 84 d1 75 27 48 3d 60 7c b1 8b 0f 92 c1 <48> 3d 7b 7c b1 8b 0f 93 c0 08 c8 74 11 48 ff c3 49 83 c7 08 49 39
RSP: 0018:ffffc9000a4ef6d8 EFLAGS: 00000083
RAX: ffffffff822fa99e RBX: 0000000000000000 RCX: 0000000000000001
RDX: 0000000000000000 RSI: 000000000000000a RDI: ffffc9000a4ef760
RBP: ffffc9000a4ef988 R08: 000000000000001e R09: ffffffff8e75e520
R10: ffffc9000a4ef678 R11: ffffffff81b0c260 R12: 000000000000000a
R13: dffffc0000000000 R14: ffffc9000a4ef760 R15: ffffc9000a4ef760
FS:  0000000000000000(0000) GS:ffff8882a945d000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 000056136e375b10 CR3: 000000011a1a2000 CR4: 00000000000006f0
Call Trace:
 <TASK>
 stack_depot_save_flags+0x33/0x810
 kasan_save_stack+0x4d/0x60
 kasan_record_aux_stack+0xbd/0xd0
 insert_work+0x3d/0x330
 __queue_work+0xd03/0x1020
 queue_delayed_work_on+0x11a/0x1e0
 process_scheduled_works+0xb6e/0x18c0
 worker_thread+0xa53/0xfc0
 kthread+0x388/0x470
 ret_from_fork+0x51e/0xb90
 ret_from_fork_asm+0x1a/0x30
 </TASK>
