INFO: task syz.7.1926:19325 blocked for more than 143 seconds.
      Not tainted syzkaller #0
"echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message.
task:syz.7.1926      state:D stack:24888 pid:19325 tgid:19322 ppid:17590  task_flags:0x400140 flags:0x00080002
Call Trace:
 <TASK>
 __schedule+0x149b/0x4fd0
 schedule+0x165/0x360
 schedule_preempt_disabled+0x13/0x30
 rwsem_down_read_slowpath+0x5fd/0x8f0
 down_read+0x99/0x2e0
 super_lock+0x2a9/0x3b0
 __iterate_supers+0x126/0x290
 __se_sys_quotactl+0x353/0x950
 do_syscall_64+0xec/0xf80
 entry_SYSCALL_64_after_hwframe+0x77/0x7f
RIP: 0033:0x7fd9e878f7c9
RSP: 002b:00007fd9e96c6038 EFLAGS: 00000246 ORIG_RAX: 00000000000000b3
RAX: ffffffffffffffda RBX: 00007fd9e89e5fa0 RCX: 00007fd9e878f7c9
RDX: 0000000000000000 RSI: 0000000000000000 RDI: ffffffff80000101
RBP: 00007fd9e87f297f R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000
R13: 00007fd9e89e6038 R14: 00007fd9e89e5fa0 R15: 00007ffe2bad2258
 </TASK>

Showing all locks held in the system:
1 lock held by khungtaskd/36:
 #0: ffffffff8df41a20 (rcu_read_lock){....}-{1:3}, at: debug_show_all_locks+0x2e/0x180
2 locks held by getty/5652:
 #0: ffff8881145450a0 (&tty->ldisc_sem){++++}-{0:0}, at: tty_ldisc_ref_wait+0x25/0x70
 #1: ffffc9000357b2f0 (&ldata->atomic_read_lock){+.+.}-{4:4}, at: n_tty_read+0x449/0x1460
4 locks held by kworker/u8:4/5858:
 #0: ffff888100ef7948 ((wq_completion)netns){+.+.}-{0:0}, at: process_scheduled_works+0x9b4/0x1770
 #1: ffffc90005077bc0 (net_cleanup_work){+.+.}-{0:0}, at: process_scheduled_works+0x9ef/0x1770
 #2: ffffffff8f304d70 (pernet_ops_rwsem){++++}-{4:4}, at: cleanup_net+0xf7/0x7a0
 #3: ffffffff8f311e08 (rtnl_mutex){+.+.}-{4:4}, at: ipmr_net_exit_batch+0x20/0x90
2 locks held by syz-executor/15742:
1 lock held by syz.7.1926/19325:
 #0: ffff8881ba5640e0 (&type->s_umount_key#84){++++}-{4:4}, at: super_lock+0x2a9/0x3b0
1 lock held by syz.6.2112/20354:
 #0: ffff8881ba5640e0 (&type->s_umount_key#84){++++}-{4:4}, at: super_lock+0x2a9/0x3b0
1 lock held by syz.4.2190/20886:
 #0: ffff8881ba5640e0 (&type->s_umount_key#84){++++}-{4:4}, at: super_lock+0x2a9/0x3b0
1 lock held by syz.7.2327/21821:
 #0: ffff8881ba5640e0 (&type->s_umount_key#84){++++}-{4:4}, at: super_lock+0x2a9/0x3b0
1 lock held by syz.7.2327/21858:
 #0: ffff8881ba5640e0 (&type->s_umount_key#84){++++}-{4:4}, at: super_lock+0x2a9/0x3b0
3 locks held by syz-executor/22486:
 #0: ffffffff8f311e08 (rtnl_mutex){+.+.}-{4:4}, at: rtnl_newlink+0x8ec/0x1c90
 #1: ffff88810a9f0d38 (&dev_instance_lock_key#20){+.+.}-{4:4}, at: do_setlink+0x388/0x41c0
 #2: ffffffff8df47578 (rcu_state.exp_mutex){+.+.}-{4:4}, at: synchronize_rcu_expedited+0x36e/0x6e0
1 lock held by syz.6.2454/22664:
 #0: ffffffff8df47578 (rcu_state.exp_mutex){+.+.}-{4:4}, at: synchronize_rcu_expedited+0x36e/0x6e0
4 locks held by dhcpcd-run-hook/22671:

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

NMI backtrace for cpu 1
CPU: 1 UID: 0 PID: 36 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+0xf95/0xfe0
 kthread+0x711/0x8a0
 ret_from_fork+0x510/0xa50
 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: 20601 Comm: kworker/u9:18 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:  0x0 (events_unbound)
RIP: 0010:worker_enter_idle+0x312/0x510
Code: 8d bd 90 00 00 00 4c 89 f8 48 c1 e8 03 49 bc 00 00 00 00 00 fc ff df 42 80 3c 20 00 74 08 4c 89 ff e8 92 66 9b 00 49 83 3f 00 <74> 07 e8 17 46 35 00 eb 3e e8 10 46 35 00 4d 8d bd 88 00 00 00 48
RSP: 0000:ffffc900046a7c30 EFLAGS: 00000082
RAX: 1ffff1102055c012 RBX: 0000000000000004 RCX: 0000000000000000
RDX: ffff88810ac1ba80 RSI: 0000000000000000 RDI: 0000000000000044
RBP: 0000000000000000 R08: ffff888100098007 R09: 1ffff11020013000
R10: dffffc0000000000 R11: ffffed1020013001 R12: dffffc0000000000
R13: ffff888102ae0000 R14: ffff888102ae0074 R15: ffff888102ae0090
FS:  0000000000000000(0000) GS:ffff88818e81f000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 00007f6a1fecc3cc CR3: 000000000dd3a000 CR4: 00000000000006f0
Call Trace:
 <TASK>
 worker_thread+0xa06/0xda0
 kthread+0x711/0x8a0
 ret_from_fork+0x510/0xa50
 ret_from_fork_asm+0x1a/0x30
 </TASK>
