INFO: task syz.0.28:6141 blocked for more than 143 seconds.
      Not tainted syzkaller #0
"echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message.
task:syz.0.28        state:D stack:26664 pid:6141  tgid:6138  ppid:5856   task_flags:0x400040 flags:0x00004004
Call Trace:
 <TASK>
 __schedule+0x1798/0x4cc0
 schedule+0x165/0x360
 schedule_preempt_disabled+0x13/0x30
 rwsem_down_write_slowpath+0x872/0xfe0
 down_write_nested+0x1b5/0x200
 filename_create+0x1f8/0x3c0
 do_mkdirat+0xa0/0x590
 __x64_sys_mkdirat+0x87/0xa0
 do_syscall_64+0xfa/0x3b0
 entry_SYSCALL_64_after_hwframe+0x77/0x7f
RIP: 0033:0x7f0e99f8ebe9
RSP: 002b:00007f0e9ad6b038 EFLAGS: 00000246 ORIG_RAX: 0000000000000102
RAX: ffffffffffffffda RBX: 00007f0e9a1c6090 RCX: 00007f0e99f8ebe9
RDX: 0000000000000000 RSI: 0000200000000400 RDI: ffffffffffffff9c
RBP: 00007f0e9a011e19 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000
R13: 00007f0e9a1c6128 R14: 00007f0e9a1c6090 R15: 00007ffcf8659858
 </TASK>
INFO: task syz.0.28:6142 blocked for more than 143 seconds.
      Not tainted syzkaller #0
"echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message.
task:syz.0.28        state:D stack:28744 pid:6142  tgid:6138  ppid:5856   task_flags:0x400040 flags:0x00004004
Call Trace:
 <TASK>
 __schedule+0x1798/0x4cc0
 schedule+0x165/0x360
 schedule_preempt_disabled+0x13/0x30
 rwsem_down_write_slowpath+0x872/0xfe0
 down_write+0x1ab/0x1f0
 path_openat+0x8da/0x3830
 do_filp_open+0x1fa/0x410
 do_sys_openat2+0x121/0x1c0
 __x64_sys_creat+0x8f/0xc0
 do_syscall_64+0xfa/0x3b0
 entry_SYSCALL_64_after_hwframe+0x77/0x7f
RIP: 0033:0x7f0e99f8ebe9
RSP: 002b:00007f0e9ad4a038 EFLAGS: 00000246 ORIG_RAX: 0000000000000055
RAX: ffffffffffffffda RBX: 00007f0e9a1c6180 RCX: 00007f0e99f8ebe9
RDX: 0000000000000000 RSI: 0000000000000000 RDI: 0000200000000100
RBP: 00007f0e9a011e19 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000
R13: 00007f0e9a1c6218 R14: 00007f0e9a1c6180 R15: 00007ffcf8659858
 </TASK>
INFO: task syz.0.28:6143 blocked for more than 143 seconds.
      Not tainted syzkaller #0
"echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message.
task:syz.0.28        state:D stack:28936 pid:6143  tgid:6138  ppid:5856   task_flags:0x400040 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
 lookup_slow+0x46/0x70
 walk_component+0x2d2/0x400
 path_lookupat+0x163/0x430
 filename_lookup+0x212/0x570
 user_path_at+0x3a/0x60
 __se_sys_mount+0x2d3/0x410
 do_syscall_64+0xfa/0x3b0
 entry_SYSCALL_64_after_hwframe+0x77/0x7f
RIP: 0033:0x7f0e99f8ebe9
RSP: 002b:00007f0e9ad29038 EFLAGS: 00000246 ORIG_RAX: 00000000000000a5
RAX: ffffffffffffffda RBX: 00007f0e9a1c6270 RCX: 00007f0e99f8ebe9
RDX: 0000000000000000 RSI: 0000200000000140 RDI: 0000200000000380
RBP: 00007f0e9a011e19 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000001000 R11: 0000000000000246 R12: 0000000000000000
R13: 00007f0e9a1c6308 R14: 00007f0e9a1c6270 R15: 00007ffcf8659858
 </TASK>
INFO: task syz.0.28:6144 blocked for more than 143 seconds.
      Not tainted syzkaller #0
"echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message.
task:syz.0.28        state:D stack:26952 pid:6144  tgid:6138  ppid:5856   task_flags:0x400040 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
 path_openat+0x8cb/0x3830
 do_filp_open+0x1fa/0x410
 do_sys_openat2+0x121/0x1c0
 __x64_sys_open+0x11e/0x150
 do_syscall_64+0xfa/0x3b0
 entry_SYSCALL_64_after_hwframe+0x77/0x7f
RIP: 0033:0x7f0e99f8ebe9
RSP: 002b:00007f0e979f2038 EFLAGS: 00000246 ORIG_RAX: 0000000000000002
RAX: ffffffffffffffda RBX: 00007f0e9a1c6360 RCX: 00007f0e99f8ebe9
RDX: 0000000000000100 RSI: 0000000000000000 RDI: 0000200000000540
RBP: 00007f0e9a011e19 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000
R13: 00007f0e9a1c63f8 R14: 00007f0e9a1c6360 R15: 00007ffcf8659858
 </TASK>
INFO: task syz.0.28:6151 blocked for more than 144 seconds.
      Not tainted syzkaller #0
"echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message.
task:syz.0.28        state:D stack:28936 pid:6151  tgid:6138  ppid:5856   task_flags:0x400040 flags:0x00004004
Call Trace:
 <TASK>
 __schedule+0x1798/0x4cc0
 schedule+0x165/0x360
 schedule_preempt_disabled+0x13/0x30
 rwsem_down_write_slowpath+0x872/0xfe0
 down_write_nested+0x1b5/0x200
 do_rmdir+0x1b2/0x550
 __x64_sys_rmdir+0x47/0x50
 do_syscall_64+0xfa/0x3b0
 entry_SYSCALL_64_after_hwframe+0x77/0x7f
RIP: 0033:0x7f0e99f8ebe9
RSP: 002b:00007f0e975cf038 EFLAGS: 00000246 ORIG_RAX: 0000000000000054
RAX: ffffffffffffffda RBX: 00007f0e9a1c6450 RCX: 00007f0e99f8ebe9
RDX: 0000000000000000 RSI: 0000000000000000 RDI: 0000200000000440
RBP: 00007f0e9a011e19 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000
R13: 00007f0e9a1c64e8 R14: 00007f0e9a1c6450 R15: 00007ffcf8659858
 </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 dhcpcd/5592:
 #0: ffffffff8f51d128 (vlan_ioctl_mutex){+.+.}-{4:4}, at: sock_ioctl+0x5ee/0x790
 #1: ffffffff8f538c48 (rtnl_mutex){+.+.}-{4:4}, at: vlan_ioctl_handler+0xd0/0x650
2 locks held by getty/5673:
 #0: ffff888026d9d0a0 (&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
4 locks held by kworker/u8:3/5878:
 #0: ffff88801b2f7148 ((wq_completion)netns){+.+.}-{0:0}, at: process_scheduled_works+0x9b4/0x17b0
 #1: ffffc9000422fbc0 (net_cleanup_work){+.+.}-{0:0}, at: process_scheduled_works+0x9ef/0x17b0
 #2: ffffffff8f52bdb0 (pernet_ops_rwsem){++++}-{4:4}, at: cleanup_net+0xf7/0x800
 #3: ffffffff8f538c48 (rtnl_mutex){+.+.}-{4:4}, at: default_device_exit_batch+0xdc/0x890
1 lock held by syz.0.28/6139:
2 locks held by syz.0.28/6141:
 #0: ffff888038e18428 (sb_writers#17){.+.+}-{0:0}, at: mnt_want_write+0x41/0x90
 #1: ffff88802a9fb5a0 (&type->i_mutex_dir_key#10/1){+.+.}-{4:4}, at: filename_create+0x1f8/0x3c0
2 locks held by syz.0.28/6142:
 #0: ffff888038e18428 (sb_writers#17){.+.+}-{0:0}, at: mnt_want_write+0x41/0x90
 #1: ffff88802a9fb5a0 (&type->i_mutex_dir_key#11){++++}-{4:4}, at: path_openat+0x8da/0x3830
1 lock held by syz.0.28/6143:
 #0: ffff88802a9fb5a0 (&type->i_mutex_dir_key#11){++++}-{4:4}, at: lookup_slow+0x46/0x70
1 lock held by syz.0.28/6144:
 #0: ffff88802a9fb5a0 (&type->i_mutex_dir_key#11){++++}-{4:4}, at: path_openat+0x8cb/0x3830
2 locks held by syz.0.28/6151:
 #0: ffff888038e18428 (sb_writers#17){.+.+}-{0:0}, at: mnt_want_write+0x41/0x90
 #1: ffff88802a9fb5a0 (&type->i_mutex_dir_key#10/1){+.+.}-{4:4}, at: do_rmdir+0x1b2/0x550
3 locks held by syz-executor/8842:
 #0: ffff88810d05cdc0 (&hdev->req_lock){+.+.}-{4:4}, at: hci_unregister_dev+0x212/0x510
 #1: ffff88810d05c0b8 (&hdev->lock){+.+.}-{4:4}, at: hci_dev_close_sync+0x66a/0x1330
 #2: ffffffff8e13f9b8 (rcu_state.exp_mutex){+.+.}-{4:4}, at: synchronize_rcu_expedited+0x3b9/0x730
4 locks held by syz.9.357/8884:
 #0: ffff888023e20dc0 (&hdev->req_lock){+.+.}-{4:4}, at: hci_unregister_dev+0x212/0x510
 #1: ffff888023e200b8 (&hdev->lock){+.+.}-{4:4}, at: hci_dev_close_sync+0x66a/0x1330
 #2: ffffffff8f69d988 (hci_cb_list_lock){+.+.}-{4:4}, at: hci_conn_hash_flush+0xa1/0x230
 #3: ffff888108d05b38 (&conn->lock#2){+.+.}-{4:4}, at: l2cap_conn_del+0x70/0x680

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

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: 5878 Comm: kworker/u8:3 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: netns cleanup_net
RIP: 0010:io_serial_in+0x77/0xc0
Code: e8 ce 71 70 fc 44 89 f9 d3 e3 49 83 c6 40 4c 89 f0 48 c1 e8 03 42 80 3c 20 00 74 08 4c 89 f7 e8 cf df d3 fc 41 03 1e 89 da ec <0f> b6 c0 5b 41 5c 41 5e 41 5f c3 cc cc cc cc cc 44 89 f9 80 e1 07
RSP: 0018:ffffc9000422eff8 EFLAGS: 00000006
RAX: 1ffffffff33be405 RBX: 00000000000003f9 RCX: 0000000000000000
RDX: 00000000000003f9 RSI: 0000000000000000 RDI: 0000000000000020
RBP: ffffc9000422f1d0 R08: 0000000000000003 R09: 0000000000000004
R10: dffffc0000000000 R11: ffffffff854f3bf0 R12: dffffc0000000000
R13: dffffc0000000000 R14: ffffffff99df2420 R15: 0000000000000000
FS:  0000000000000000(0000) GS:ffff8880b8618000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 00007ffdfdd29fe8 CR3: 000000011221c000 CR4: 00000000000006f0
Call Trace:
 <TASK>
 serial8250_console_write+0x584/0x1ba0
 console_flush_all+0x728/0xc40
 console_unlock+0xc4/0x270
 vprintk_emit+0x5b7/0x7a0
 _printk+0xcf/0x120
 batadv_hardif_disable_interface+0x2b9/0xf20
 batadv_meshif_destroy_netlink+0x68/0x250
 default_device_exit_batch+0x769/0x890
 ops_undo_list+0x525/0x990
 cleanup_net+0x4c5/0x800
 process_scheduled_works+0xae1/0x17b0
 worker_thread+0x8a0/0xda0
 kthread+0x711/0x8a0
 ret_from_fork+0x3fc/0x770
 ret_from_fork_asm+0x1a/0x30
 </TASK>
