INFO: task syz.9.2937:17923 blocked in I/O wait for more than 143 
INFO: task syz.9.2937:17923 blocked in I/O wait for more than 143 seconds.
      Tainted: G             L      syzkaller #0
"echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message.
task:syz.9.2937      state:D stack:25520 pid:17923 tgid:17922 ppid:17354  task_flags:0x400140 flags:0x00080002
Call Trace:
 <TASK>
 context_switch kernel/sched/core.c:5520 [inline]
 __schedule+0x1259/0x6920 kernel/sched/core.c:7270
 __schedule_loop kernel/sched/core.c:7347 [inline]
 schedule+0xdd/0x2c0 kernel/sched/core.c:7362
 io_schedule+0x8a/0xf0 kernel/sched/core.c:8190
 folio_wait_bit_common+0x414/0xa80 mm/filemap.c:1329
 folio_lock include/linux/pagemap.h:1220 [inline]
 migrate_folio_unmap mm/migrate.c:1260 [inline]
 migrate_pages_batch+0x165f/0x4680 mm/migrate.c:1918
 migrate_pages_sync+0x4db/0x880 mm/migrate.c:2062
 migrate_pages+0x1a83/0x2850 mm/migrate.c:2144
 compact_zone+0x2643/0x4640 mm/compaction.c:2698
 compact_node+0x17f/0x2c0 mm/compaction.c:2945
 compact_nodes mm/compaction.c:2967 [inline]
 sysctl_compaction_handler mm/compaction.c:3018 [inline]
 sysctl_compaction_handler+0x141/0x210 mm/compaction.c:3005
 proc_sys_call_handler+0x47f/0x5a0 fs/proc/proc_sysctl.c:600
 iter_file_splice_write+0x830/0x10b0 fs/splice.c:736
 do_splice_from fs/splice.c:936 [inline]
 direct_splice_actor+0x192/0x690 fs/splice.c:1159
 splice_direct_to_actor+0x345/0xa30 fs/splice.c:1103
 do_splice_direct_actor fs/splice.c:1202 [inline]
 do_splice_direct+0x174/0x240 fs/splice.c:1228
 do_sendfile+0xadc/0xe20 fs/read_write.c:1371
 __do_sys_sendfile64 fs/read_write.c:1426 [inline]
 __se_sys_sendfile64 fs/read_write.c:1418 [inline]
 __x64_sys_sendfile64+0x154/0x220 fs/read_write.c:1418
 do_syscall_x64 arch/x86/entry/syscall_64.c:61 [inline]
 do_syscall_64+0x123/0x790 arch/x86/entry/syscall_64.c:84
 entry_SYSCALL_64_after_hwframe+0x77/0x7f
RIP: 0033:0x7fa57859e159
RSP: 002b:00007fa5767f6028 EFLAGS: 00000246 ORIG_RAX: 0000000000000028
RAX: ffffffffffffffda RBX: 00007fa578825fa0 RCX: 00007fa57859e159
RDX: 00002000000000c0 RSI: 000000000000000a RDI: 000000000000000b
RBP: 00007fa578635024 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000005 R11: 0000000000000246 R12: 0000000000000000
R13: 00007fa578826038 R14: 00007fa578825fa0 R15: 00007ffd27ddaaa8
 </TASK>

Showing all locks held in the system:
locks held by pr/ttyS0/16: 2, last CPU#0:
 #0: ffffffff8edd8338 (console_srcu){....}-{0:0}, at: rcu_try_lock_acquire include/linux/rcupdate.h:314 [inline]
 #0: ffffffff8edd8338 (console_srcu){....}-{0:0}, at: srcu_read_lock_nmisafe include/linux/srcu.h:439 [inline]
 #0: ffffffff8edd8338 (console_srcu){....}-{0:0}, at: console_srcu_read_lock+0x49/0x60 kernel/printk/printk.c:291
 #1: ffffffff9bc60c78 (&port_lock_key){-.-.}-{3:3}, at: __uart_port_lock_irqsave include/linux/serial_core.h:613 [inline]
 #1: ffffffff9bc60c78 (&port_lock_key){-.-.}-{3:3}, at: univ8250_console_device_lock+0x64/0xc0 drivers/tty/serial/8250/8250_core.c:413
locks held by khungtaskd/44: 1, last CPU#3:
 #0: ffffffff8edec060 (rcu_read_lock){....}-{1:3}, at: rcu_lock_acquire include/linux/rcupdate.h:309 [inline]
 #0: ffffffff8edec060 (rcu_read_lock){....}-{1:3}, at: rcu_read_lock include/linux/rcupdate.h:849 [inline]
 #0: ffffffff8edec060 (rcu_read_lock){....}-{1:3}, at: debug_show_all_locks+0x3d/0x184 kernel/locking/lockdep.c:6837
locks held by kworker/1:2/64: 2, last CPU#1:
 #0: ffff88801c0c7540 ((wq_completion)events_power_efficient){+.+.}-{0:0}, at: process_one_work+0x1466/0x1b10 kernel/workqueue.c:3362
 #1: ffffc90000b1fd08 ((work_completion)(&(&tbl->gc_work)->work)){+.+.}-{0:0}, at: process_one_work+0xa2c/0x1b10 kernel/workqueue.c:3363
locks held by getty/5531: 2, on CPU#3:
 #0: ffff8880297b60a0 (&tty->ldisc_sem){++++}-{0:0}, at: tty_ldisc_ref_wait+0x24/0x80 drivers/tty/tty_ldisc.c:243
 #1: ffffc900000dd2e8 (&ldata->atomic_read_lock){+.+.}-{4:4}, at: n_tty_read+0x419/0x14e0 drivers/tty/n_tty.c:2211
locks held by udevd/10062: 1, on CPU#2:
 #0: ffff8880281c3350 (&disk->open_mutex){+.+.}-{4:4}, at: bdev_open+0x41a/0xe40 block/bdev.c:990
locks held by syz.9.2937/17923: 1, on CPU#3:
 #0: ffff888025e84460 (sb_writers#3){.+.+}-{0:0}, at: splice_direct_to_actor+0x345/0xa30 fs/splice.c:1103

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

NMI backtrace for cpu 3
CPU: 3 UID: 0 PID: 44 Comm: khungtaskd Tainted: G             L      syzkaller #0 PREEMPT(full) 
Tainted: [L]=SOFTLOCKUP
Hardware name: QEMU Standard PC (Q35 + ICH9, 2009), BIOS 1.16.3-debian-1.16.3-2 04/01/2014
Call Trace:
 <TASK>
 __dump_stack lib/dump_stack.c:94 [inline]
 dump_stack_lvl+0x100/0x190 lib/dump_stack.c:120
 nmi_cpu_backtrace.cold+0x12d/0x151 lib/nmi_backtrace.c:123
 nmi_trigger_cpumask_backtrace+0x21f/0x2a0 lib/nmi_backtrace.c:66
 trigger_all_cpu_backtrace include/linux/nmi.h:164 [inline]
 __sys_info lib/sys_info.c:157 [inline]
 sys_info+0x141/0x190 lib/sys_info.c:165
 check_hung_uninterruptible_tasks kernel/hung_task.c:353 [inline]
 watchdog+0xcb1/0x1030 kernel/hung_task.c:561
 kthread+0x373/0x450 kernel/kthread.c:436
 ret_from_fork+0x730/0xd60 arch/x86/kernel/process.c:158
 ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:245
 </TASK>
Sending NMI from CPU 3 to CPUs 0-2:
NMI backtrace for cpu 0
CPU: 0 UID: 0 PID: 16 Comm: pr/ttyS0 Tainted: G             L      syzkaller #0 PREEMPT(full) 
Tainted: [L]=SOFTLOCKUP
Hardware name: QEMU Standard PC (Q35 + ICH9, 2009), BIOS 1.16.3-debian-1.16.3-2 04/01/2014
RIP: 0010:io_serial_out+0x8f/0xb0 drivers/tty/serial/8250/8250_port.c:416
Code: 48 8d 7d 40 44 89 e1 48 b8 00 00 00 00 00 fc ff df 48 89 fa d3 e3 48 c1 ea 03 80 3c 02 00 75 1c 66 03 5d 40 44 89 e8 89 da ee <5b> 5d 41 5c 41 5d c3 cc cc cc cc e8 91 31 cf fc eb a0 e8 1a 32 cf
RSP: 0018:ffffc900001379e0 EFLAGS: 00000002
RAX: 0000000000000063 RBX: 00000000000003f8 RCX: 0000000000000000
RDX: 00000000000003f8 RSI: ffffffff85afc6c5 RDI: ffffffff9bc60ca0
RBP: ffffffff9bc60c60 R08: 0000000000000001 R09: 000000000000001f
R10: 0000000000000000 R11: 6174203a4f464e49 R12: 0000000000000000
R13: 0000000000000063 R14: 0000000000000006 R15: ffffc90000137da8
FS:  0000000000000000(0000) GS:ffff8880d5b64000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 00007fb71876f708 CR3: 000000000eb96000 CR4: 0000000000352ef0
Call Trace:
 <TASK>
 serial_port_out include/linux/serial_core.h:817 [inline]
 serial8250_console_putchar drivers/tty/serial/8250/8250_port.c:3287 [inline]
 __serial8250_console_fifo_write+0xd6/0x290 drivers/tty/serial/8250/8250_port.c:3359
 serial8250_console_fifo_write drivers/tty/serial/8250/8250_port.c:3378 [inline]
 __serial8250_console_write drivers/tty/serial/8250/8250_port.c:3429 [inline]
 serial8250_console_write+0xf46/0x1330 drivers/tty/serial/8250/8250_port.c:3493
 nbcon_emit_next_record+0x8f7/0xa70 kernel/printk/nbcon.c:1070
 nbcon_emit_one+0x1a8/0x2b0 kernel/printk/nbcon.c:1157
 nbcon_kthread_func+0x613/0x7d0 kernel/printk/nbcon.c:1271
 kthread+0x373/0x450 kernel/kthread.c:436
 ret_from_fork+0x730/0xd60 arch/x86/kernel/process.c:158
 ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:245
 </TASK>
NMI backtrace for cpu 2
CPU: 2 UID: 0 PID: 0 Comm: swapper/2 Tainted: G             L      syzkaller #0 PREEMPT(full) 
Tainted: [L]=SOFTLOCKUP
Hardware name: QEMU Standard PC (Q35 + ICH9, 2009), BIOS 1.16.3-debian-1.16.3-2 04/01/2014
RIP: 0010:pv_native_safe_halt+0xf/0x20 arch/x86/kernel/paravirt.c:64
Code: 58 9c 02 e9 43 4f 03 00 0f 1f 00 90 90 90 90 90 90 90 90 90 90 90 90 90 90 90 90 f3 0f 1e fa eb 07 0f 00 2d c3 86 1c 00 fb f4 <c3> cc cc cc cc 66 2e 0f 1f 84 00 00 00 00 00 66 90 90 90 90 90 90
RSP: 0018:ffffc90000197e00 EFLAGS: 00000202
RAX: 00000000003575c7 RBX: ffff88801f2f2580 RCX: ffffffff8bcf3115
RDX: 0000000000000001 RSI: ffffffff8e3eaa9b RDI: ffffffff8c620c80
RBP: ffffed1003e5e4b0 R08: 0000000000000001 R09: ffffed100d4c67bd
R10: ffff88806a633deb R11: 0000000000000000 R12: 0000000000000000
R13: 0000000000000000 R14: 1ffff92000032fc4 R15: dffffc0000000000
FS:  0000000000000000(0000) GS:ffff8880d5d64000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 00007fb71876f708 CR3: 000000000eb96000 CR4: 0000000000352ef0
DR0: ffffffffffffffff DR1: 00000000000001f8 DR2: 0000000000000002
DR3: ffffffffefffff15 DR6: 00000000ffff0ff0 DR7: 0000000000000400
Call Trace:
 <TASK>
 arch_safe_halt arch/x86/include/asm/paravirt.h:62 [inline]
 default_idle+0x9/0x10 arch/x86/kernel/process.c:768
 default_idle_call+0x6c/0xb0 kernel/sched/idle.c:122
 cpuidle_idle_call kernel/sched/idle.c:199 [inline]
 do_idle+0x3ae/0x5b0 kernel/sched/idle.c:355
 cpu_startup_entry+0x4f/0x60 kernel/sched/idle.c:454
 start_secondary+0x21d/0x2d0 arch/x86/kernel/smpboot.c:312
 common_startup_64+0x13e/0x158
 </TASK>
NMI backtrace for cpu 1
CPU: 1 UID: 0 PID: 64 Comm: kworker/1:2 Tainted: G             L      syzkaller #0 PREEMPT(full) 
Tainted: [L]=SOFTLOCKUP
Hardware name: QEMU Standard PC (Q35 + ICH9, 2009), BIOS 1.16.3-debian-1.16.3-2 04/01/2014
Workqueue: events_power_efficient neigh_periodic_work
RIP: 0010:__raw_spin_unlock_irqrestore include/linux/spinlock_api_smp.h:211 [inline]
RIP: 0010:_raw_spin_unlock_irqrestore+0x31/0x80 kernel/locking/spinlock.c:221
Code: f5 53 48 8b 74 24 10 48 89 fb 48 83 c7 18 e8 a6 09 15 f6 48 89 df e8 ce 5f 15 f6 f7 c5 00 02 00 00 75 23 9c 58 f6 c4 02 75 37 <bf> 01 00 00 00 e8 15 68 04 f6 65 48 83 3d 64 a5 b9 08 00 74 16 5b
RSP: 0018:ffffc900006b0f28 EFLAGS: 00000246
RAX: 0000000000000006 RBX: ffff88806a528500 RCX: 0000000000000004
RDX: 0000000000000102 RSI: ffffffff8e3eaa9b RDI: ffffffff8c620c80
RBP: 0000000000000287 R08: 0000000000000001 R09: 0000000000000000
R10: 0000000000000001 R11: 0000000000000001 R12: 0000000000000100
R13: 0000000000000008 R14: 8000000000000101 R15: 0000000000000001
FS:  0000000000000000(0000) GS:ffff8880d5c64000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 00007f707beb9ff8 CR3: 000000002c15b000 CR4: 0000000000352ef0
DR0: 0000000000000009 DR1: 0000000000000004 DR2: 0000000000000006
DR3: 00000000000000d0 DR6: 00000000ffff0ff0 DR7: 0000000000000400
Call Trace:
 <IRQ>
 handle_softirqs+0x1e6/0x9d0 kernel/softirq.c:645
 do_softirq kernel/softirq.c:546 [inline]
 do_softirq+0xaf/0xf0 kernel/softirq.c:533
 </IRQ>
 <TASK>
 __local_bh_enable_ip+0xff/0x120 kernel/softirq.c:473
 spin_unlock_bh include/linux/spinlock.h:407 [inline]
 neigh_periodic_work+0x6da/0xc10 net/core/neighbour.c:1035
 process_one_work+0xac7/0x1b10 kernel/workqueue.c:3387
 process_scheduled_works kernel/workqueue.c:3470 [inline]
 worker_thread+0x5ef/0xe50 kernel/workqueue.c:3551
 kthread+0x373/0x450 kernel/kthread.c:436
 ret_from_fork+0x730/0xd60 arch/x86/kernel/process.c:158
 ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:245
 </TASK>