INFO: task syz.4.484:9837 blocked for more than 143 seconds.
      Not tainted syzkaller #0
"echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message.
task:syz.4.484       state:D stack:28920 pid:9837  tgid:9835  ppid:9237   task_flags:0x400040 flags:0x00080002
Call Trace:
 <TASK>
 __schedule+0x16f9/0x5500
 rt_mutex_schedule+0x76/0xf0
 __rt_mutex_slowlock_locked+0x1f28/0x2550
 __rwbase_read_lock+0xc3/0x180
 down_read+0x132/0x200
 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: 0033:0x7f1d622ccdd9
RSP: 002b:00007f1d6051e028 EFLAGS: 00000246 ORIG_RAX: 00000000000000a2
RAX: ffffffffffffffda RBX: 00007f1d62545fa0 RCX: 00007f1d622ccdd9
RDX: 0000000000000000 RSI: 0000000000000000 RDI: 0000000000000000
RBP: 00007f1d62545fa0 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000
R13: 00007f1d62546038 R14: 00007f1d62545fa0 R15: 00007ffcb1402468
 </TASK>
INFO: task syz.4.484:9840 blocked for more than 143 seconds.
      Not tainted syzkaller #0
"echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message.
task:syz.4.484       state:D stack:28920 pid:9840  tgid:9835  ppid:9237   task_flags:0x400040 flags:0x00080002
Call Trace:
 <TASK>
 __schedule+0x16f9/0x5500
 rt_mutex_schedule+0x76/0xf0
 __rt_mutex_slowlock_locked+0x1f28/0x2550
 __rwbase_read_lock+0xc3/0x180
 down_read+0x132/0x200
 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: 0033:0x7f1d622ccdd9
RSP: 002b:00007f1d604fd028 EFLAGS: 00000246 ORIG_RAX: 00000000000000a2
RAX: ffffffffffffffda RBX: 00007f1d62546090 RCX: 00007f1d622ccdd9
RDX: 0000000000000000 RSI: 0000000000000000 RDI: 0000000000000000
RBP: 00007f1d62546090 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000
R13: 00007f1d62546128 R14: 00007f1d62546090 R15: 00007ffcb1402468
 </TASK>
INFO: task syz.4.484:9841 blocked for more than 143 seconds.
      Not tainted syzkaller #0
"echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message.
task:syz.4.484       state:D stack:28920 pid:9841  tgid:9835  ppid:9237   task_flags:0x400040 flags:0x00080002
Call Trace:
 <TASK>
 __schedule+0x16f9/0x5500
 rt_mutex_schedule+0x76/0xf0
 __rt_mutex_slowlock_locked+0x1f28/0x2550
 __rwbase_read_lock+0xc3/0x180
 down_read+0x132/0x200
 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: 0033:0x7f1d622ccdd9
RSP: 002b:00007f1d604dc028 EFLAGS: 00000246 ORIG_RAX: 00000000000000a2
RAX: ffffffffffffffda RBX: 00007f1d62546180 RCX: 00007f1d622ccdd9
RDX: 0000000000000000 RSI: 0000000000000000 RDI: 0000000000000000
RBP: 00007f1d62546180 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000
R13: 00007f1d62546218 R14: 00007f1d62546180 R15: 00007ffcb1402468
 </TASK>
INFO: task syz.4.484:9845 blocked for more than 143 seconds.
      Not tainted syzkaller #0
"echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message.
task:syz.4.484       state:D stack:28920 pid:9845  tgid:9835  ppid:9237   task_flags:0x400040 flags:0x00080002
Call Trace:
 <TASK>
 __schedule+0x16f9/0x5500
 rt_mutex_schedule+0x76/0xf0
 __rt_mutex_slowlock_locked+0x1f28/0x2550
 __rwbase_read_lock+0xc3/0x180
 down_read+0x132/0x200
 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: 0033:0x7f1d622ccdd9
RSP: 002b:00007f1d600b9028 EFLAGS: 00000246 ORIG_RAX: 00000000000000a2
RAX: ffffffffffffffda RBX: 00007f1d62546270 RCX: 00007f1d622ccdd9
RDX: 0000000000000000 RSI: 0000000000000000 RDI: 0000000000000000
RBP: 00007f1d62546270 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000
R13: 00007f1d62546308 R14: 00007f1d62546270 R15: 00007ffcb1402468
 </TASK>
INFO: task syz.4.484:9848 blocked for more than 143 seconds.
      Not tainted syzkaller #0
"echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message.
task:syz.4.484       state:D stack:28920 pid:9848  tgid:9835  ppid:9237   task_flags:0x400040 flags:0x00080002
Call Trace:
 <TASK>
 __schedule+0x16f9/0x5500
 rt_mutex_schedule+0x76/0xf0
 __rt_mutex_slowlock_locked+0x1f28/0x2550
 __rwbase_read_lock+0xc3/0x180
 down_read+0x132/0x200
 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: 0033:0x7f1d622ccdd9
RSP: 002b:00007f1d5fc96028 EFLAGS: 00000246 ORIG_RAX: 00000000000000a2
RAX: ffffffffffffffda RBX: 00007f1d62546360 RCX: 00007f1d622ccdd9
RDX: 0000000000000000 RSI: 0000000000000000 RDI: 0000000000000000
RBP: 00007f1d62546360 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000
R13: 00007f1d625463f8 R14: 00007f1d62546360 R15: 00007ffcb1402468
 </TASK>
INFO: task syz.4.484:9851 blocked for more than 143 seconds.
      Not tainted syzkaller #0
"echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message.
task:syz.4.484       state:D stack:28600 pid:9851  tgid:9835  ppid:9237   task_flags:0x400040 flags:0x00080002
Call Trace:
 <TASK>
 __schedule+0x16f9/0x5500
 rt_mutex_schedule+0x76/0xf0
 __rt_mutex_slowlock_locked+0x1f28/0x2550
 __rwbase_read_lock+0xc3/0x180
 down_read+0x132/0x200
 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: 0033:0x7f1d622ccdd9
RSP: 002b:00007f1d5f873028 EFLAGS: 00000246 ORIG_RAX: 00000000000000a2
RAX: ffffffffffffffda RBX: 00007f1d62546450 RCX: 00007f1d622ccdd9
RDX: 0000000000000000 RSI: 0000000000000000 RDI: 0000000000000000
RBP: 00007f1d62546450 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000
R13: 00007f1d625464e8 R14: 00007f1d62546450 R15: 00007ffcb1402468
 </TASK>
INFO: task syz.4.484:9853 blocked for more than 143 seconds.
      Not tainted syzkaller #0
"echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message.
task:syz.4.484       state:D stack:28920 pid:9853  tgid:9835  ppid:9237   task_flags:0x400040 flags:0x00080002
Call Trace:
 <TASK>
 __schedule+0x16f9/0x5500
 rt_mutex_schedule+0x76/0xf0
 __rt_mutex_slowlock_locked+0x1f28/0x2550
 __rwbase_read_lock+0xc3/0x180
 down_read+0x132/0x200
 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: 0033:0x7f1d622ccdd9
RSP: 002b:00007f1d5f450028 EFLAGS: 00000246 ORIG_RAX: 00000000000000a2
RAX: ffffffffffffffda RBX: 00007f1d62546540 RCX: 00007f1d622ccdd9
RDX: 0000000000000000 RSI: 0000000000000000 RDI: 0000000000000000
RBP: 00007f1d62546540 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000
R13: 00007f1d625465d8 R14: 00007f1d62546540 R15: 00007ffcb1402468
 </TASK>
INFO: task syz.4.484:9855 blocked for more than 143 seconds.
      Not tainted syzkaller #0
"echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message.
task:syz.4.484       state:D stack:28536 pid:9855  tgid:9835  ppid:9237   task_flags:0x400040 flags:0x00080002
Call Trace:
 <TASK>
 __schedule+0x16f9/0x5500
 rt_mutex_schedule+0x76/0xf0
 __rt_mutex_slowlock_locked+0x1f28/0x2550
 __rwbase_read_lock+0xc3/0x180
 down_read+0x132/0x200
 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: 0033:0x7f1d622ccdd9
RSP: 002b:00007f1d5f02d028 EFLAGS: 00000246 ORIG_RAX: 00000000000000a2
RAX: ffffffffffffffda RBX: 00007f1d62546630 RCX: 00007f1d622ccdd9
RDX: 0000000000000000 RSI: 0000000000000000 RDI: 0000000000000000
RBP: 00007f1d62546630 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000
R13: 00007f1d625466c8 R14: 00007f1d62546630 R15: 00007ffcb1402468
 </TASK>

Showing all locks held in the system:
3 locks held by kworker/u8:0/12:
 #0: ffff888176811938 ((wq_completion)ipv6_addrconf){+.+.}-{0:0}, at: process_one_work+0x897/0x1630
 #1: ffffc90000117c40 ((work_completion)(&(&ifa->dad_work)->work)){+.+.}-{0:0}, at: process_one_work+0x8be/0x1630
 #2: ffffffff8f371f78 (rtnl_mutex){+.+.}-{4:4}, at: addrconf_dad_work+0x124/0x1680
3 locks held by kworker/u8:1/13:
 #0: ffff8881012ad938 ((wq_completion)netns){+.+.}-{0:0}, at: process_one_work+0x897/0x1630
 #1: ffffc90000127c40 (net_cleanup_work){+.+.}-{0:0}, at: process_one_work+0x8be/0x1630
 #2: ffffffff8dfce430 (rcu_state.barrier_mutex){+.+.}-{4:4}, at: rcu_barrier+0x4c/0x580
1 lock held by khungtaskd/43:
 #0: ffffffff8dfc8240 (rcu_read_lock){....}-{1:3}, at: debug_show_all_locks+0x2e/0x180
3 locks held by dhcpcd/5330:
 #0: ffffffff8e6ea4f8 (tomoyo_ss){.+.+}-{0:0}, at: tomoyo_check_open_permission+0x1d3/0x470
 #1: ffffffff8dfc8240 (rcu_read_lock){....}-{1:3}, at: prepend_path+0x4d/0x830
 #2: ffffffff8dfc8240 (rcu_read_lock){....}-{1:3}, at: prepend_path+0x4d/0x830
2 locks held by getty/5413:
 #0: ffff88810da520a0 (&tty->ldisc_sem){++++}-{0:0}, at: tty_ldisc_ref_wait+0x25/0x70
 #1: ffffc90003f062e0 (&ldata->atomic_read_lock){+.+.}-{4:4}, at: n_tty_read+0x462/0x13a0
3 locks held by kworker/0:4/5667:
 #0: ffff88810006f938 ((wq_completion)events){+.+.}-{0:0}, at: process_one_work+0x897/0x1630
 #1: ffffc90005b57c40 ((work_completion)(&data->fib_event_work)){+.+.}-{0:0}, at: process_one_work+0x8be/0x1630
 #2: ffff88817c627280 (&data->fib_lock){+.+.}-{4:4}, at: nsim_fib_event_work+0x222/0x3e0
2 locks held by syz-executor/9225:
 #0: ffff8881109be0d0 (&type->s_umount_key#53){++++}-{4:4}, at: deactivate_super+0xa9/0xe0
 #1: ffff888186c30348 (&sbi->cp_global_sem_key#2){+.+.}-{4:4}, at: f2fs_write_checkpoint+0x2ed/0x26a0
1 lock held by syz.4.484/9837:
 #0: ffff8881109be0d0 (&type->s_umount_key#53){++++}-{4:4}, at: super_lock+0x2d6/0x3d0
1 lock held by syz.4.484/9840:
 #0: ffff8881109be0d0 (&type->s_umount_key#53){++++}-{4:4}, at: super_lock+0x2d6/0x3d0
1 lock held by syz.4.484/9841:
 #0: ffff8881109be0d0 (&type->s_umount_key#53){++++}-{4:4}, at: super_lock+0x2d6/0x3d0
1 lock held by syz.4.484/9845:
 #0: ffff8881109be0d0 (&type->s_umount_key#53){++++}-{4:4}, at: super_lock+0x2d6/0x3d0
1 lock held by syz.4.484/9848:
 #0: ffff8881109be0d0 (&type->s_umount_key#53){++++}-{4:4}, at: super_lock+0x2d6/0x3d0
1 lock held by syz.4.484/9851:
 #0: ffff8881109be0d0 (&type->s_umount_key#53){++++}-{4:4}, at: super_lock+0x2d6/0x3d0
1 lock held by syz.4.484/9853:
 #0: ffff8881109be0d0 (&type->s_umount_key#53){++++}-{4:4}, at: super_lock+0x2d6/0x3d0
1 lock held by syz.4.484/9855:
 #0: ffff8881109be0d0 (&type->s_umount_key#53){++++}-{4:4}, at: super_lock+0x2d6/0x3d0
1 lock held by syz-executor/11167:
 #0: ffffffff8f371f78 (rtnl_mutex){+.+.}-{4:4}, at: rtnetlink_rcv_msg+0x722/0xbe0
1 lock held by syz-executor/11379:
 #0: ffffffff8f371f78 (rtnl_mutex){+.+.}-{4:4}, at: rtnl_newlink+0x883/0x1bb0
3 locks held by syz.2.612/11505:
 #0: ffff8881012d4480 (sb_writers#5){.+.+}-{0:0}, at: vfs_write+0x22d/0xba0
 #1: ffff8881706fd5b0 (&sb->s_type->i_mutex_key#15){+.+.}-{4:4}, at: shmem_file_write_iter+0x82/0x120
 #2: ffffffff8dfc8240 (rcu_read_lock){....}-{1:3}, at: unwind_next_frame+0xa6/0x2550

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

NMI backtrace for cpu 0
CPU: 0 UID: 0 PID: 43 Comm: khungtaskd Not tainted syzkaller #0 PREEMPT_{RT,(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: 17 Comm: pr/legacy Not tainted syzkaller #0 PREEMPT_{RT,(full)} 
Hardware name: QEMU Standard PC (Q35 + ICH9, 2009), BIOS 1.16.2-debian-1.16.2-1 04/01/2014
RIP: 0010:io_serial_out+0x7c/0xc0
Code: 21 87 fc 44 89 f9 d3 e5 49 83 ee 80 4c 89 f0 48 c1 e8 03 42 80 3c 20 00 74 08 4c 89 f7 e8 cc bb f0 fc 41 03 2e 89 d8 89 ea ee <5b> 41 5c 41 5e 41 5f 5d c3 cc cc cc cc cc 44 89 f9 80 e1 07 38 c1
RSP: 0018:ffffc90000167a30 EFLAGS: 00000202
RAX: 0000000000000074 RBX: 0000000000000074 RCX: 0000000000000000
RDX: 00000000000003f8 RSI: 0000000000000000 RDI: 0000000000000000
RBP: 00000000000003f8 R08: 0000000000000000 R09: 0000000000000000
R10: dffffc0000000000 R11: ffffffff853da9e0 R12: dffffc0000000000
R13: 0000000000000001 R14: ffffffff99b6eb00 R15: 0000000000000000
FS:  0000000000000000(0000) GS:ffff8882a9f1f000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 00007fa0148b5000 CR3: 000000018dfd8000 CR4: 00000000000006f0
Call Trace:
 <TASK>
 serial8250_console_write+0x12e1/0x1b90
 console_flush_one_record+0x68b/0xb90
 legacy_kthread_func+0x1b6/0x250
 kthread+0x388/0x470
 ret_from_fork+0x514/0xb70
 ret_from_fork_asm+0x1a/0x30
 </TASK>
