INFO: task syz.2.475:8117 blocked for more than 143 seconds.
      Not tainted syzkaller #0
"echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message.
task:syz.2.475       state:D stack:28712 pid:8117  tgid:8114  ppid:7774   task_flags:0x400040 flags:0x00080002
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/0xfa0
 entry_SYSCALL_64_after_hwframe+0x77/0x7f
RIP: 0033:0x7f707358f749
RSP: 002b:00007f70744e7038 EFLAGS: 00000246 ORIG_RAX: 00000000000000b3
RAX: ffffffffffffffda RBX: 00007f70737e6090 RCX: 00007f707358f749
RDX: 0000000000000000 RSI: 0000200000000c80 RDI: ffffffff80000900
RBP: 00007f7073613f91 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000
R13: 00007f70737e6128 R14: 00007f70737e6090 R15: 00007ffe0ba0eac8
 </TASK>
INFO: task syz.0.476:8120 blocked for more than 143 seconds.
      Not tainted syzkaller #0
"echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message.
task:syz.0.476       state:D stack:26344 pid:8120  tgid:8119  ppid:7498   task_flags:0x400140 flags:0x00080002
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
 ksys_sync+0x94/0x150
 __ia32_sys_sync+0xe/0x20
 do_syscall_64+0xfa/0xfa0
 entry_SYSCALL_64_after_hwframe+0x77/0x7f
RIP: 0033:0x7f046158f749
RSP: 002b:00007f04624fa038 EFLAGS: 00000246 ORIG_RAX: 00000000000000a2
RAX: ffffffffffffffda RBX: 00007f04617e5fa0 RCX: 00007f046158f749
RDX: 0000000000000000 RSI: 0000000000000000 RDI: 0000000000000000
RBP: 00007f04617e5fa0 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000
R13: 00007f04617e6038 R14: 00007f04617e5fa0 R15: 00007ffcbad0c6b8
 </TASK>

Showing all locks held in the system:
3 locks held by kworker/0:0/9:
 #0: ffff888100075948 ((wq_completion)events){+.+.}-{0:0}, at: process_scheduled_works+0x9b4/0x17b0
 #1: ffffc900000e7ba0 (deferred_process_work){+.+.}-{0:0}, at: process_scheduled_works+0x9ef/0x17b0
 #2: ffffffff8f2cc908 (rtnl_mutex){+.+.}-{4:4}, at: switchdev_deferred_process_work+0xe/0x20
2 locks held by kworker/u9:0/26:
1 lock held by khungtaskd/35:
 #0: ffffffff8df3d6a0 (rcu_read_lock){....}-{1:3}, at: debug_show_all_locks+0x2e/0x180
2 locks held by getty/5640:
 #0: ffff888173fc20a0 (&tty->ldisc_sem){++++}-{0:0}, at: tty_ldisc_ref_wait+0x25/0x70
 #1: ffffc9000357b2f0 (&ldata->atomic_read_lock){+.+.}-{4:4}, at: n_tty_read+0x43e/0x1400
2 locks held by syz-executor/5811:
3 locks held by syz-executor/5815:
2 locks held by syz-executor/5816:
3 locks held by kworker/u8:3/5844:
 #0: ffff88817379b148 ((wq_completion)ipv6_addrconf){+.+.}-{0:0}, at: process_scheduled_works+0x9b4/0x17b0
 #1: ffffc90005227ba0 ((work_completion)(&(&net->ipv6.addr_chk_work)->work)){+.+.}-{0:0}, at: process_scheduled_works+0x9ef/0x17b0
 #2: ffffffff8f2cc908 (rtnl_mutex){+.+.}-{4:4}, at: addrconf_verify_work+0x19/0x30
3 locks held by kworker/0:3/5851:
 #0: ffff888100076948 ((wq_completion)events_power_efficient){+.+.}-{0:0}, at: process_scheduled_works+0x9b4/0x17b0
 #1: ffffc90005287ba0 ((reg_check_chans).work){+.+.}-{0:0}, at: process_scheduled_works+0x9ef/0x17b0
 #2: ffffffff8f2cc908 (rtnl_mutex){+.+.}-{4:4}, at: reg_check_chans_work+0xa1/0xf40
2 locks held by syz-executor/6099:
2 locks held by syz-executor/6120:
2 locks held by syz-executor/6334:
2 locks held by syz-executor/6442:
1 lock held by syz.2.475/8117:
 #0: ffff8881112ea0e0 (&type->s_umount_key#53){++++}-{4:4}, at: super_lock+0x2a9/0x3b0
1 lock held by syz.0.476/8120:
 #0: ffff8881731760e0 (&type->s_umount_key#53){++++}-{4:4}, at: super_lock+0x2a9/0x3b0
4 locks held by syz-executor/8206:
1 lock held by udevd/8446:
 #0: ffff88810a645358 (&disk->open_mutex){+.+.}-{4:4}, at: bdev_open+0xe0/0xd30
4 locks held by syz.3.665/8938:
 #0: ffff8881b877e420 (sb_writers#10){.+.+}-{0:0}, at: mnt_want_write+0x41/0x90
 #1: ffff888021d31528 (&type->i_mutex_dir_key#7/1){+.+.}-{4:4}, at: filename_create+0x1f8/0x3c0
 #2: ffffffff8df75528 (cgroup_mutex){+.+.}-{4:4}, at: cgroup_kn_lock_live+0x13c/0x230
 #3: ffffffff8f2cc908 (rtnl_mutex){+.+.}-{4:4}, at: cgrp_css_online+0x91/0x300
2 locks held by syz.3.665/8945:
 #0: ffffffff8f332790 (cb_lock){++++}-{4:4}, at: genl_rcv+0x19/0x40
 #1: ffffffff8f2cc908 (rtnl_mutex){+.+.}-{4:4}, at: nl80211_pre_doit+0x5f/0x930
2 locks held by syz.1.666/8940:
 #0: ffffffff8f2cc908 (rtnl_mutex){+.+.}-{4:4}, at: tun_chr_close+0x3e/0x1c0
 #1: ffffffff8df43138 (rcu_state.exp_mutex){+.+.}-{4:4}, at: synchronize_rcu_expedited+0x2f6/0x730
1 lock held by syz.4.667/8947:
 #0: ffffffff8f2cc908 (rtnl_mutex){+.+.}-{4:4}, at: rtnetlink_rcv_msg+0x71c/0xb70
1 lock held by syz-executor/8953:
 #0: ffffffff8f2cc908 (rtnl_mutex){+.+.}-{4:4}, at: inet_rtm_newaddr+0x3b0/0x18b0
1 lock held by syz-executor/8955:
 #0: ffffffff8f2cc908 (rtnl_mutex){+.+.}-{4:4}, at: inet_rtm_newaddr+0x3b0/0x18b0
1 lock held by syz-executor/8958:
 #0: ffffffff8f2cc908 (rtnl_mutex){+.+.}-{4:4}, at: inet_rtm_newaddr+0x3b0/0x18b0

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

NMI backtrace for cpu 0
CPU: 0 UID: 0 PID: 35 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+0xf60/0xfa0
 kthread+0x711/0x8a0
 ret_from_fork+0x4bc/0x870
 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: 8206 Comm: syz-executor 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:__sanitizer_cov_trace_pc+0x37/0x70
Code: 08 a0 6e 92 65 8b 15 b8 86 ae 10 81 e2 00 01 ff 00 74 11 81 fa 00 01 00 00 75 35 83 b9 7c 16 00 00 00 74 2c 8b 91 58 16 00 00 <83> fa 02 75 21 48 8b 91 60 16 00 00 48 8b 32 48 8d 7e 01 8b 89 5c
RSP: 0018:ffffc9000711f628 EFLAGS: 00000246
RAX: ffffffff8245b8a0 RBX: ffff88802c8bbf98 RCX: ffff888176230000
RDX: 0000000000000000 RSI: 0000000000000000 RDI: 0000000000000000
RBP: 0000000000000002 R08: ffff88802c8bc0cb R09: 1ffff11005917819
R10: dffffc0000000000 R11: ffffed100591781a R12: 0000000000000000
R13: ffff88802c8bbf48 R14: ffff88802c8bbec8 R15: 1ffff110059177f3
FS:  0000555576737500(0000) GS:ffff8882a9f36000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 00005651764a8e38 CR3: 00000001b9ce2000 CR4: 00000000000006f0
Call Trace:
 <TASK>
 writeback_single_inode+0xb0/0x6a0
 sync_inode_metadata+0xb9/0x110
 f2fs_write_checkpoint+0xaf2/0x2440
 kill_f2fs_super+0x2cc/0x6d0
 deactivate_locked_super+0xbc/0x130
 cleanup_mnt+0x425/0x4c0
 task_work_run+0x1d4/0x260
 exit_to_user_mode_loop+0xe9/0x130
 do_syscall_64+0x2bd/0xfa0
 entry_SYSCALL_64_after_hwframe+0x77/0x7f
RIP: 0033:0x7f8d25990a77
Code: a8 ff ff ff f7 d8 64 89 01 48 83 c8 ff c3 0f 1f 44 00 00 31 f6 e9 09 00 00 00 66 0f 1f 84 00 00 00 00 00 b8 a6 00 00 00 0f 05 <48> 3d 00 f0 ff ff 77 01 c3 48 c7 c2 a8 ff ff ff f7 d8 64 89 02 b8
RSP: 002b:00007ffc73f1cd48 EFLAGS: 00000246 ORIG_RAX: 00000000000000a6
RAX: 0000000000000000 RBX: 00007f8d25a13d7d RCX: 00007f8d25990a77
RDX: 0000000000000000 RSI: 0000000000000009 RDI: 00007ffc73f1ce00
RBP: 00007ffc73f1ce00 R08: 0000000000000000 R09: 0000000000000000
R10: 00000000ffffffff R11: 0000000000000246 R12: 00007ffc73f1de90
R13: 00007f8d25a13d7d R14: 0000000000055449 R15: 00007ffc73f1ded0
 </TASK>
