INFO: task syz.4.3066:29182 blocked for more than 143 seconds.
      Not tainted syzkaller #0
"echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message.
task:syz.4.3066      state:D stack:28120 pid:29182 tgid:29181 ppid:26498  task_flags:0x400140 flags:0x00080002
Call Trace:
 <TASK>
 __schedule+0x1821/0x5740
 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
 __ia32_sys_sync+0xa0/0x120
 do_syscall_64+0x15f/0xf80
 entry_SYSCALL_64_after_hwframe+0x77/0x7f
RIP: 0033:0x7f30fc39ce59
RSP: 002b:00007f30fd2f2028 EFLAGS: 00000246 ORIG_RAX: 00000000000000a2
RAX: ffffffffffffffda RBX: 00007f30fc615fa0 RCX: 00007f30fc39ce59
RDX: 0000000000000000 RSI: 0000000000000000 RDI: 0000000000000000
RBP: 00007f30fc615fa0 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000
R13: 00007f30fc616038 R14: 00007f30fc615fa0 R15: 00007ffcdb718b58
 </TASK>
INFO: task syz.4.3066:29183 blocked for more than 143 seconds.
      Not tainted syzkaller #0
"echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message.
task:syz.4.3066      state:D stack:28760 pid:29183 tgid:29181 ppid:26498  task_flags:0x400040 flags:0x00080002
Call Trace:
 <TASK>
 __schedule+0x1821/0x5740
 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
 __ia32_sys_sync+0xa0/0x120
 do_syscall_64+0x15f/0xf80
 entry_SYSCALL_64_after_hwframe+0x77/0x7f
RIP: 0033:0x7f30fc39ce59
RSP: 002b:00007f30fd2d1028 EFLAGS: 00000246 ORIG_RAX: 00000000000000a2
RAX: ffffffffffffffda RBX: 00007f30fc616090 RCX: 00007f30fc39ce59
RDX: 0000000000000000 RSI: 0000000000000000 RDI: 0000000000000000
RBP: 00007f30fc616090 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000
R13: 00007f30fc616128 R14: 00007f30fc616090 R15: 00007ffcdb718b58
 </TASK>

Showing all locks held in the system:
2 locks held by ksoftirqd/0/15:
1 lock held by khungtaskd/35:
 #0: ffffffff8e95cca0 (rcu_read_lock){....}-{1:3}, at: debug_show_all_locks+0x2e/0x180
2 locks held by dhcpcd/5356:
 #0: ffff88810e8ce6e8 (nlk_cb_mutex-ROUTE){+.+.}-{4:4}, at: netlink_dump+0xe2/0xe10
 #1: ffffffff8fdd1300 (rtnl_mutex){+.+.}-{4:4}, at: rtnl_dumpit+0x92/0x200
2 locks held by getty/5439:
 #0: ffff888110b7d0a0 (&tty->ldisc_sem){++++}-{0:0}, at: tty_ldisc_ref_wait+0x25/0x70
 #1: ffffc900034732e8 (&ldata->atomic_read_lock){+.+.}-{4:4}, at: n_tty_read+0x45c/0x13a0
5 locks held by kworker/u8:2/5653:
 #0: ffff8881012b5940 ((wq_completion)netns){+.+.}-{0:0}, at: process_scheduled_works+0xa35/0x1860
 #1: ffffc90004c1fc40 (net_cleanup_work){+.+.}-{0:0}, at: process_scheduled_works+0xa70/0x1860
 #2: ffffffff8fdc2628 (pernet_ops_rwsem){++++}-{4:4}, at: cleanup_net+0xf4/0x800
 #3: ffffffff8fdd1300 (rtnl_mutex){+.+.}-{4:4}, at: ops_undo_list+0x2a4/0x940
 #4: ffffffff8e962fa8 (rcu_state.exp_mutex){+.+.}-{4:4}, at: synchronize_rcu_expedited+0x38d/0x770
4 locks held by kworker/0:3/5693:
3 locks held by kworker/1:7/5726:
 #0: ffff88810006b140 ((wq_completion)events){+.+.}-{0:0}, at: process_scheduled_works+0xa35/0x1860
 #1: ffffc90005c17c40 ((work_completion)(&data->fib_event_work)){+.+.}-{0:0}, at: process_scheduled_works+0xa70/0x1860
 #2: ffff8881b9e72250 (&data->fib_lock){+.+.}-{4:4}, at: nsim_fib_event_work+0x202/0x3d0
3 locks held by kworker/1:8/7955:
 #0: ffff88810006b140 ((wq_completion)events){+.+.}-{0:0}, at: process_scheduled_works+0xa35/0x1860
 #1: ffffc900045bfc40 (deferred_process_work){+.+.}-{0:0}, at: process_scheduled_works+0xa70/0x1860
 #2: ffffffff8fdd1300 (rtnl_mutex){+.+.}-{4:4}, at: switchdev_deferred_process_work+0xe/0x20
3 locks held by kworker/0:8/9112:
 #0: ffff88810006b140 ((wq_completion)events){+.+.}-{0:0}, at: process_scheduled_works+0xa35/0x1860
 #1: ffffc900039d7c40 (rx_mode_work){+.+.}-{0:0}, at: process_scheduled_works+0xa70/0x1860
 #2: ffffffff8fdd1300 (rtnl_mutex){+.+.}-{4:4}, at: netdev_rx_mode_work+0x19/0x3c0
2 locks held by syz-executor/24182:
1 lock held by syz.4.3066/29182:
 #0: ffff8881bb6ea0d8 (&type->s_umount_key#56){++++}-{4:4}, at: super_lock+0x2d6/0x3d0
1 lock held by syz.4.3066/29183:
 #0: ffff8881bb6ea0d8 (&type->s_umount_key#56){++++}-{4:4}, at: super_lock+0x2d6/0x3d0
2 locks held by syz-executor/32000:
 #0: ffff88811c4940d8 (&type->s_umount_key#58){++++}-{4:4}, at: deactivate_super+0xa9/0xe0
 #1: ffffffff8edf8a40 (jfs_log_mutex){+.+.}-{4:4}, at: lmLogClose+0xb4/0x520
1 lock held by syz.0.3424/2902:
 #0: ffff8881bb6ea0d8 (&type->s_umount_key#56){++++}-{4:4}, at: super_lock+0x2d6/0x3d0
1 lock held by syz.0.3424/2903:
 #0: ffff8881bb6ea0d8 (&type->s_umount_key#56){++++}-{4:4}, at: super_lock+0x2d6/0x3d0
2 locks held by syz-executor/3362:
 #0: ffff88811442e0d8 (&type->s_umount_key#58){++++}-{4:4}, at: deactivate_super+0xa9/0xe0
 #1: ffffffff8edf8a40 (jfs_log_mutex){+.+.}-{4:4}, at: lmLogClose+0xb4/0x520
2 locks held by syz-executor/4643:
 #0: ffffffff8fdc2628 (pernet_ops_rwsem){++++}-{4:4}, at: copy_net_ns+0x4f7/0x730
 #1: ffffffff8fdd1300 (rtnl_mutex){+.+.}-{4:4}, at: ip_tunnel_init_net+0x2d7/0x840

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

NMI backtrace for cpu 1
CPU: 1 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+0xfd3/0x1030
 kthread+0x389/0x470
 ret_from_fork+0x514/0xb70
 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: 802 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:save_trace+0x6c/0x390
Code: 00 00 e8 87 e8 0e 00 89 43 14 44 8d 04 c5 00 00 00 00 8d 3c c5 ef be ad de 41 83 f8 0d 0f 82 bf 00 00 00 89 fa 89 f9 4c 89 f6 <03> 3e 03 56 04 03 4e 08 41 89 c9 41 c1 c1 04 29 cf 41 31 f9 01 d1
RSP: 0018:ffffc90008e873e8 EFLAGS: 00000012
RAX: 000000000000000f RBX: ffffffff96874f90 RCX: 00000000c34daff4
RDX: 00000000d1eb5816 RSI: ffffffff96874fc0 RDI: 00000000b9fbf181
RBP: 4813a9b3d73f7929 R08: 0000000000000060 R09: 00000000c0b07fcd
R10: 0000000035d04413 R11: 00000000bdbbc6a5 R12: ffffffff96d6be18
R13: ffff88810a046438 R14: ffffffff96874fa8 R15: 0000000000089ce8
FS:  0000555590f52500(0000) GS:ffff88818dc87000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 00007f49ece87e20 CR3: 000000000e74a000 CR4: 00000000000006f0
Call Trace:
 <TASK>
 __lock_acquire+0x1e87/0x2cf0
 lock_acquire+0x106/0x350
 touch_wq_lockdep_map+0xcb/0x180
 __flush_workqueue+0x14b/0x14f0
 drain_workqueue+0xd3/0x390
 hci_dev_close_sync+0x62f/0x10e0
 hci_unregister_dev+0x21a/0x5a0
 vhci_release+0x152/0x1a0
 __fput+0x44f/0xa60
 task_work_run+0x1d9/0x270
 do_exit+0x70f/0x22c0
 do_group_exit+0x21b/0x2d0
 get_signal+0x1284/0x1330
 arch_do_signal_or_restart+0xbc/0x840
 exit_to_user_mode_loop+0x8c/0x4d0
 do_syscall_64+0x33e/0xf80
 entry_SYSCALL_64_after_hwframe+0x77/0x7f
RIP: 0033:0x7f6b6df5d68e
Code: Unable to access opcode bytes at 0x7f6b6df5d664.
RSP: 002b:00007ffec5c369b8 EFLAGS: 00000246 ORIG_RAX: 0000000000000101
RAX: 0000000000000005 RBX: 0000555590f52500 RCX: 00007f6b6df5d68e
RDX: 0000000000000000 RSI: 00007ffec5c36b20 RDI: ffffffffffffff9c
RBP: 00007ffec5c36b20 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 00007ffec5c37bb0
R13: 00007f6b6e0321ca R14: 0000555590f524e8 R15: 0000000000000005
 </TASK>
