INFO: task syz.1.6161:24172 blocked for more than 143 seconds.
      Not tainted syzkaller #0
"echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message.
task:syz.1.6161      state:D stack:25752 pid:24172 tgid:24171 ppid:11529  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
 __se_sys_quotactl+0x353/0x950
 do_syscall_64+0xfa/0x3b0
 entry_SYSCALL_64_after_hwframe+0x77/0x7f
RIP: 0033:0x7f5ba7d8ebe9
RSP: 002b:00007f5ba8b57038 EFLAGS: 00000246 ORIG_RAX: 00000000000000b3
RAX: ffffffffffffffda RBX: 00007f5ba7fc5fa0 RCX: 00007f5ba7d8ebe9
RDX: 0000000000000000 RSI: 0000000000000000 RDI: ffffffff80000101
RBP: 00007f5ba7e11e19 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000
R13: 00007f5ba7fc6038 R14: 00007f5ba7fc5fa0 R15: 00007ffd0ae3b3d8
 </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/5677:
 #0: ffff8880287170a0 (&tty->ldisc_sem){++++}-{0:0}, at: tty_ldisc_ref_wait+0x25/0x70
 #1: ffffc900027c82f0 (&ldata->atomic_read_lock){+.+.}-{4:4}, at: n_tty_read+0x43e/0x1400
1 lock held by syz-executor/5775:
3 locks held by kworker/u8:4/5878:
 #0: ffff88810f8a9148 ((wq_completion)ipv6_addrconf){+.+.}-{0:0}, at: process_scheduled_works+0x9b4/0x17b0
 #1: ffffc900047cfbc0 ((work_completion)(&(&ifa->dad_work)->work)){+.+.}-{0:0}, at: process_scheduled_works+0x9ef/0x17b0
 #2: ffffffff8f538c48 (rtnl_mutex){+.+.}-{4:4}, at: addrconf_dad_work+0x112/0x14b0
5 locks held by kworker/u8:0/1437:
 #0: ffff88801b2f7148 ((wq_completion)netns){+.+.}-{0:0}, at: process_scheduled_works+0x9b4/0x17b0
 #1: ffffc900031efbc0 (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
 #4: ffffffff8e13f9b8 (rcu_state.exp_mutex){+.+.}-{4:4}, at: synchronize_rcu_expedited+0x2f6/0x730
3 locks held by kworker/u10:24/15319:
 #0: ffff88801a489148 ((wq_completion)events_unbound){+.+.}-{0:0}, at: process_scheduled_works+0x9b4/0x17b0
 #1: ffffc900032dfbc0 ((linkwatch_work).work){+.+.}-{0:0}, at: process_scheduled_works+0x9ef/0x17b0
 #2: ffffffff8f538c48 (rtnl_mutex){+.+.}-{4:4}, at: linkwatch_event+0xe/0x60
2 locks held by syz-executor/20638:
1 lock held by syz.1.6161/24172:
 #0: ffff88810575c0e0 (&type->s_umount_key#112){++++}-{4:4}, at: super_lock+0x2a9/0x3b0
1 lock held by syz-executor/28959:
 #0: ffffffff8f538c48 (rtnl_mutex){+.+.}-{4:4}, at: rtnl_newlink+0x8db/0x1c70
1 lock held by syz-executor/29325:
1 lock held by syz-executor/29348:
 #0: ffffffff8f538c48 (rtnl_mutex){+.+.}-{4:4}, at: rtnl_newlink+0x8db/0x1c70

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

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: 5711 Comm: kworker/u8:2 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_nc_worker
RIP: 0010:__lock_acquire+0x50e/0xd20
Code: c7 28 41 89 c4 48 39 cb 0f 8d d6 00 00 00 48 83 fb 31 0f 83 92 00 00 00 41 8b 07 25 ff 1f 00 00 48 0f a3 05 a4 dd 0a 12 73 10 <48> 69 c0 c8 00 00 00 48 8d 88 10 43 49 93 eb 40 83 3d 0b 6d 0e 18
RSP: 0018:ffffc90002ddf8f0 EFLAGS: 00000003
RAX: 0000000000000780 RBX: 0000000000000000 RCX: 00000000ffffffff
RDX: 0000000000000003 RSI: 0000000000000000 RDI: ffff888022a6d640
RBP: 0000000000000000 R08: 0000000000000000 R09: ffffffff8b475462
R10: dffffc0000000000 R11: ffffffff8b475390 R12: ffffffffffffff05
R13: 0000000000000001 R14: ffff888022a6e180 R15: ffff888022a6e150
FS:  0000000000000000(0000) GS:ffff8880b8618000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 000020000002a000 CR3: 000000012f6b8000 CR4: 00000000000006f0
Call Trace:
 <TASK>
 lock_acquire+0x120/0x360
 batadv_nc_worker+0xef/0x610
 process_scheduled_works+0xae1/0x17b0
 worker_thread+0x8a0/0xda0
 kthread+0x711/0x8a0
 ret_from_fork+0x3fc/0x770
 ret_from_fork_asm+0x1a/0x30
 </TASK>
