INFO: task syz.9.623:11315 blocked for more than 143 seconds.
      Not tainted syzkaller #0
"echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message.
task:syz.9.623       state:D stack:24472 pid:11315 tgid:11314 ppid:10152  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: 0033:0x7efe7559ce59
RSP: 002b:00007efe764bb028 EFLAGS: 00000246 ORIG_RAX: 00000000000000a2
RAX: ffffffffffffffda RBX: 00007efe75815fa0 RCX: 00007efe7559ce59
RDX: 0000000000000000 RSI: 0000000000000000 RDI: 0000000000000000
RBP: 00007efe75815fa0 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000
R13: 00007efe75816038 R14: 00007efe75815fa0 R15: 00007ffc1eb827a8
 </TASK>

Showing all locks held in the system:
1 lock held by khungtaskd/34:
 #0: ffffffff8e95cd60 (rcu_read_lock){....}-{1:3}, at: debug_show_all_locks+0x2e/0x180
1 lock held by dhcpcd/5355:
2 locks held by getty/5440:
 #0: ffff888114edb0a0 (&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
2 locks held by syz-executor/5612:
1 lock held by syz.9.623/11315:
 #0: ffff88816d34a0d8 (&type->s_umount_key#53){++++}-{4:4}, at: super_lock+0x2d6/0x3d0
1 lock held by syz-executor/14467:
 #0: ffffffff8e963068 (rcu_state.exp_mutex){+.+.}-{4:4}, at: synchronize_rcu_expedited+0x38d/0x770
5 locks held by syz-executor/15053:
2 locks held by syz.7.1089/15507:

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

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+0xfd3/0x1030
 kthread+0x388/0x470
 ret_from_fork+0x514/0xb70
 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: 13 Comm: kworker/u8:1 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: bat_events batadv_iv_send_outstanding_bat_ogm_packet
RIP: 0010:__lock_acquire+0x87/0x2cf0
Code: 0c 85 c9 44 0f 44 c1 31 c9 48 3d 70 03 fd 93 41 0f 45 c8 89 4c 24 10 8b 0d 46 de a2 18 85 c9 0f 95 c0 83 fe 08 0f 92 c2 08 c2 <0f> 84 49 01 00 00 83 fe 01 77 0c 89 f0 49 8b 44 c1 08 48 85 c0 75
RSP: 0018:ffffc900001276f8 EFLAGS: 00000002
RAX: ffffffff9a48bb00 RBX: 0000000000000000 RCX: 0000000000000000
RDX: 0000000000000001 RSI: 0000000000000000 RDI: ffffffff8e95cd60
RBP: 0000000000000000 R08: 0000000000000000 R09: ffffffff8e95cd60
R10: dffffc0000000000 R11: ffffed10337f8f17 R12: 0000000000000002
R13: 0000000000000002 R14: 0000000000000000 R15: 0000000000000000
FS:  0000000000000000(0000) GS:ffff8882a928d000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 000055a5f8534a18 CR3: 00000001b2628000 CR4: 00000000000006f0
Call Trace:
 <TASK>
 lock_acquire+0x106/0x350
 batadv_iv_ogm_schedule+0x45e/0xf50
 batadv_iv_send_outstanding_bat_ogm_packet+0x6c8/0x7e0
 process_scheduled_works+0xb5d/0x1860
 worker_thread+0xa53/0xfc0
 kthread+0x388/0x470
 ret_from_fork+0x514/0xb70
 ret_from_fork_asm+0x1a/0x30
 </TASK>
