INFO: task syz.6.541:10374 blocked for more than 143 seconds.
      Not tainted syzkaller #0
"echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message.
task:syz.6.541       state:D stack:25128 pid:10374 tgid:10373 ppid:9892   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
 super_lock+0x2a9/0x3b0
 user_get_super+0xc8/0x120
 __se_sys_quotactl+0x4da/0x950
 do_syscall_64+0xfa/0x3b0
 entry_SYSCALL_64_after_hwframe+0x77/0x7f
RIP: 0033:0x7fce1bb8eba9
RSP: 002b:00007fce1ca60038 EFLAGS: 00000246 ORIG_RAX: 00000000000000b3
RAX: ffffffffffffffda RBX: 00007fce1bdd5fa0 RCX: 00007fce1bb8eba9
RDX: 0000000000000000 RSI: 0000200000000200 RDI: ffffffff80000402
RBP: 00007fce1bc11e19 R08: 0000000000000000 R09: 0000000000000000
R10: 0000200000000280 R11: 0000000000000246 R12: 0000000000000000
R13: 00007fce1bdd6038 R14: 00007fce1bdd5fa0 R15: 00007ffd64b818f8
 </TASK>

Showing all locks held in the system:
1 lock held by khungtaskd/34:
 #0: ffffffff8e13a0e0 (rcu_read_lock){....}-{1:3}, at: debug_show_all_locks+0x2e/0x180
1 lock held by dhcpcd/5597:
 #0: ffffffff8f539f48 (rtnl_mutex){+.+.}-{4:4}, at: devinet_ioctl+0x323/0x1b50
2 locks held by getty/5684:
 #0: ffff8881365620a0 (&tty->ldisc_sem){++++}-{0:0}, at: tty_ldisc_ref_wait+0x25/0x70
 #1: ffffc900029032f0 (&ldata->atomic_read_lock){+.+.}-{4:4}, at: n_tty_read+0x43e/0x1400
4 locks held by kworker/u8:2/5686:
 #0: ffff88801b2f7148 ((wq_completion)netns){+.+.}-{0:0}, at: process_scheduled_works+0x9b4/0x17b0
 #1: ffffc90002f7fbc0 (net_cleanup_work){+.+.}-{0:0}, at: process_scheduled_works+0x9ef/0x17b0
 #2: ffffffff8f52d090 (pernet_ops_rwsem){++++}-{4:4}, at: cleanup_net+0xf7/0x800
 #3: ffffffff8f539f48 (rtnl_mutex){+.+.}-{4:4}, at: mpls_net_exit+0x79/0x270
4 locks held by syz-executor/6625:
1 lock held by syz.6.541/10374:
 #0: ffff88810a9c60e0 (&type->s_umount_key#56){++++}-{4:4}, at: super_lock+0x2a9/0x3b0
2 locks held by syz-executor/11714:
 #0: ffffffff8e88ef08 (bio_slab_lock){+.+.}-{4:4}, at: bioset_exit+0x44a/0x690
 #1: ffffffff8e13fa40 (rcu_state.barrier_mutex){+.+.}-{4:4}, at: rcu_barrier+0x4c/0x570
3 locks held by syz-executor/13139:
 #0: ffffffff8eca94a0 (&ops->srcu#2){.+.+}-{0:0}, at: rtnl_link_ops_get+0x23/0x250
 #1: ffffffff8f539f48 (rtnl_mutex){+.+.}-{4:4}, at: rtnl_newlink+0x8db/0x1c70
 #2: ffffffff8e13fb78 (rcu_state.exp_mutex){+.+.}-{4:4}, at: synchronize_rcu_expedited+0x2f6/0x730

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

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+0x189/0x250
 nmi_cpu_backtrace+0x39e/0x3d0
 nmi_trigger_cpumask_backtrace+0x17a/0x300
 watchdog+0xf93/0xfe0
 kthread+0x711/0x8a0
 ret_from_fork+0x439/0x7d0
 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: 13273 Comm: syz.6.811 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:__handle_mm_fault+0x1f6/0x5440
Code: 8b 7d 10 4d 8d 75 20 4c 89 f0 48 c1 e8 03 48 89 44 24 30 42 80 3c 20 00 74 08 4c 89 f7 e8 72 22 18 00 4c 89 74 24 28 49 8b 06 <48> 89 44 24 10 4c 89 7c 24 38 49 81 c7 b8 00 00 00 4c 89 f8 48 c1
RSP: 0000:ffffc90002ebfc00 EFLAGS: 00000246
RAX: 0000000008100073 RBX: 00007f3f7b554000 RCX: 0000000000000000
RDX: 0000000000000000 RSI: 0000000000000000 RDI: ffffc90002ebfd50
RBP: ffffc90002ebfdd0 R08: 0000000000000004 R09: 0000000000000004
R10: ffffc90002ebfd0c R11: fffff520005d7faa R12: dffffc0000000000
R13: ffff888115f2ef00 R14: ffff888115f2ef20 R15: ffff88810fc9e0c0
FS:  00007f3f862ce6c0(0000) GS:ffff8881a3c15000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 00007f3f7b554000 CR3: 000000004219a000 CR4: 00000000000006f0
Call Trace:
 <TASK>
 handle_mm_fault+0x40a/0x8e0
 do_user_addr_fault+0xa81/0x1390
 exc_page_fault+0x76/0xf0
 asm_exc_page_fault+0x26/0x30
RIP: 0033:0x7f3f85250c46
Code: f0 72 6e 48 63 cd 48 01 c1 49 39 4f 08 72 4c 8d 4d ff 85 ed 74 33 66 0f 1f 44 00 00 48 39 f0 72 1b 4d 8b 07 49 89 c1 49 29 f1 <47> 0f b6 0c 08 45 84 c9 74 08 45 88 0c 00 49 8b 47 10 48 83 c0 01
RSP: 002b:00007f3f862cd4a0 EFLAGS: 00010206
RAX: 0000000000554001 RBX: 00007f3f862cd540 RCX: 0000000000000049
RDX: 0000000000000000 RSI: 0000000000000001 RDI: 00007f3f862cd5e0
RBP: 0000000000000102 R08: 00007f3f7b000000 R09: 0000000000554000
R10: 0000000000000000 R11: 00007f3f862cd550 R12: 0000000000000001
R13: 00007f3f8542da20 R14: 0000000000000000 R15: 00007f3f862cd5e0
 </TASK>
