INFO: task syz.6.1597:12358 blocked in I/O wait for more than 143 
INFO: task syz.6.1597:12358 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.6.1597      state:D stack:25328 pid:12358 tgid:12356 ppid:11005  task_flags:0x400040 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: 0033:0x7f76ddb9e159
RSP: 002b:00007f76dbdd5028 EFLAGS: 00000246 ORIG_RAX: 0000000000000028
RAX: ffffffffffffffda RBX: 00007f76dde26090 RCX: 00007f76ddb9e159
RDX: 00002000000000c0 RSI: 0000000000000003 RDI: 0000000000000004
RBP: 00007f76ddc35024 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000005 R11: 0000000000000246 R12: 0000000000000000
R13: 00007f76dde26128 R14: 00007f76dde26090 R15: 00007ffcacb89388
 </TASK>

Showing all locks held in the system:
locks held by kworker/0:1/10: 3, on CPU#0:
 #0: ffff88801c0aa940 ((wq_completion)events){+.+.}-{0:0}, at: process_one_work+0x1466/0x1b10 kernel/workqueue.c:3371
 #1: ffffc900000d7d08 ((work_completion)(&data->fib_event_work)){+.+.}-{0:0}, at: process_one_work+0xa2c/0x1b10 kernel/workqueue.c:3372
 #2: ffff888025ea1250 (&data->fib_lock){+.+.}-{4:4}, at: nsim_fib_event_work+0x1b8/0x6330 drivers/net/netdevsim/fib.c:1490
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: ffffffff9bc65c78 (&port_lock_key){-.-.}-{3:3}, at: __uart_port_lock_irqsave include/linux/serial_core.h:613 [inline]
 #1: ffffffff9bc65c78 (&port_lock_key){-.-.}-{3:3}, at: univ8250_console_device_lock+0x64/0xc0 drivers/tty/serial/8250/8250_core.c:413
locks held by khungtaskd/45: 1, last CPU#1:
 #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 dhcpcd/5443: 2, last CPU#3:
 #0: ffff888035b5f470 (&u->iolock){+.+.}-{4:4}, at: add_wait_queue+0x45/0x230 kernel/sched/wait.c:24
 #1: ffffffff8edec060 (rcu_read_lock){....}-{1:3}, at: rcu_lock_acquire include/linux/rcupdate.h:309 [inline]
 #1: ffffffff8edec060 (rcu_read_lock){....}-{1:3}, at: rcu_read_lock include/linux/rcupdate.h:849 [inline]
 #1: ffffffff8edec060 (rcu_read_lock){....}-{1:3}, at: class_rcu_constructor include/linux/rcupdate.h:1216 [inline]
 #1: ffffffff8edec060 (rcu_read_lock){....}-{1:3}, at: unwind_next_frame+0xbd/0x2090 arch/x86/kernel/unwind_orc.c:495
locks held by getty/5532: 2, on CPU#2:
 #0: ffff88802a5f70a0 (&tty->ldisc_sem){++++}-{0:0}, at: tty_ldisc_ref_wait+0x24/0x80 drivers/tty/tty_ldisc.c:243
 #1: ffffc9000337b2e8 (&ldata->atomic_read_lock){+.+.}-{4:4}, at: n_tty_read+0x419/0x14e0 drivers/tty/n_tty.c:2211
locks held by udevd/9470: 1, on CPU#3:
 #0: ffff888028792350 (&disk->open_mutex){+.+.}-{4:4}, at: bdev_open+0x41a/0xe40 block/bdev.c:990
locks held by syz.6.1597/12358: 1, on CPU#3:
 #0: ffff88804b078460 (sb_writers#3){.+.+}-{0:0}, at: splice_direct_to_actor+0x345/0xa30 fs/splice.c:1103

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

NMI backtrace for cpu 1
CPU: 1 UID: 0 PID: 45 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 1 to CPUs 0,2-3:
NMI backtrace for cpu 2
CPU: 2 UID: 101 PID: 5442 Comm: dhcpcd 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:__lock_acquire+0xf1/0x1ec0 kernel/locking/lockdep.c:5161
Code: 48 2d a0 dd 90 96 48 89 c5 48 b8 29 5c 8f c2 f5 28 5c 8f 48 c1 fd 03 48 0f af e8 44 89 d0 48 8d 0c 80 49 8d 84 24 b0 0b 00 00 <48> c1 e1 03 45 85 d2 0f 84 ce 06 00 00 f6 84 24 c8 00 00 00 01 48
RSP: 0018:ffffc900058ef268 EFLAGS: 00000803
RAX: ffff888025fb3130 RBX: 0000000000000000 RCX: 0000000000000000
RDX: 0000000000000000 RSI: 0000000000000000 RDI: ffffffff8edec060
RBP: 0000000000000007 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000001 R12: ffff888025fb2580
R13: 0000000000000002 R14: 0000000000000000 R15: ffffffff8edec060
FS:  00007fb4b03fe780(0000) GS:ffff8880d5d5f000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 00007efcae4da6b0 CR3: 000000003d1f5000 CR4: 0000000000352ef0
Call Trace:
 <TASK>
 lock_acquire kernel/locking/lockdep.c:5908 [inline]
 lock_acquire+0x1d1/0x380 kernel/locking/lockdep.c:5865
 rcu_lock_acquire include/linux/rcupdate.h:309 [inline]
 rcu_read_lock include/linux/rcupdate.h:849 [inline]
 class_rcu_constructor include/linux/rcupdate.h:1216 [inline]
 unwind_next_frame+0xd1/0x2090 arch/x86/kernel/unwind_orc.c:495
 arch_stack_walk+0x94/0xf0 arch/x86/kernel/stacktrace.c:25
 stack_trace_save+0x8e/0xc0 kernel/stacktrace.c:122
 kasan_save_stack+0x30/0x50 mm/kasan/common.c:57
 kasan_save_track+0x14/0x30 mm/kasan/common.c:78
 unpoison_slab_object mm/kasan/common.c:340 [inline]
 __kasan_slab_alloc+0x89/0x90 mm/kasan/common.c:366
 kasan_slab_alloc include/linux/kasan.h:253 [inline]
 slab_post_alloc_hook mm/slub.c:4683 [inline]
 slab_alloc_node mm/slub.c:4996 [inline]
 kmem_cache_alloc_node_noprof+0x282/0x6e0 mm/slub.c:5068
 __alloc_skb+0x140/0x710 net/core/skbuff.c:704
 alloc_skb include/linux/skbuff.h:1384 [inline]
 alloc_skb_with_frags+0xdd/0x760 net/core/skbuff.c:6789
 sock_alloc_send_pskb+0x801/0x980 net/core/sock.c:3015
 unix_dgram_sendmsg+0x3c7/0x1810 net/unix/af_unix.c:2144
 unix_seqpacket_sendmsg+0x12a/0x1d0 net/unix/af_unix.c:2545
 sock_sendmsg_nosec net/socket.c:800 [inline]
 __sock_sendmsg net/socket.c:815 [inline]
 sock_write_iter+0x53a/0x5b0 net/socket.c:1266
 new_sync_write fs/read_write.c:595 [inline]
 vfs_write+0x6af/0x1050 fs/read_write.c:687
 ksys_write+0x1f8/0x250 fs/read_write.c:739
 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: 0033:0x7fb4b0488407
Code: 48 89 fa 4c 89 df e8 38 aa 00 00 8b 93 08 03 00 00 59 5e 48 83 f8 fc 74 1a 5b c3 0f 1f 84 00 00 00 00 00 48 8b 44 24 10 0f 05 <5b> c3 0f 1f 80 00 00 00 00 83 e2 39 83 fa 08 75 de e8 23 ff ff ff
RSP: 002b:00007ffe26b24800 EFLAGS: 00000202 ORIG_RAX: 0000000000000001
RAX: ffffffffffffffda RBX: 00007fb4b03fe780 RCX: 00007fb4b0488407
RDX: 0000000000000040 RSI: 00007ffe26b24860 RDI: 0000000000000005
RBP: 000055651a7b9168 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000202 R12: 00007ffe26b24c90
R13: 0000556557da90c0 R14: 0000556557d8b710 R15: 0000556557d8b6e0
 </TASK>
NMI backtrace for cpu 3
CPU: 3 UID: 0 PID: 5443 Comm: dhcpcd 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:__rcu_read_lock+0x4f/0x70 kernel/rcu/tree_plugin.h:416
Code: 0f b6 14 02 48 89 f8 83 e0 07 83 c0 03 38 d0 7c 04 84 d2 75 2c 8b 83 c4 04 00 00 83 c0 01 89 83 c4 04 00 00 8b 83 c4 04 00 00 <3d> ff ff ff 3f 7f 06 5b e9 44 84 e3 09 90 0f 0b 90 5b c3 cc cc cc
RSP: 0018:ffffc90003597550 EFLAGS: 00000202
RAX: 0000000000000001 RBX: ffff8880237d2580 RCX: ffffc90003597524
RDX: 0000000000000000 RSI: ffffffff89965fe5 RDI: ffff8880237d2a44
RBP: ffffc90003597618 R08: 0000000000000001 R09: 0000000000000007
R10: 0000000000000200 R11: 0000000000089581 R12: ffffffff81f5cf20
R13: ffffc900035975d0 R14: 0000000000000000 R15: ffff8880237d2580
FS:  00007fb4b03fe780(0000) GS:ffff8880d5e5f000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 00007f4f9c6d6e9c CR3: 0000000035fc5000 CR4: 0000000000352ef0
Call Trace:
 <TASK>
 rcu_read_lock include/linux/rcupdate.h:847 [inline]
 class_rcu_constructor include/linux/rcupdate.h:1216 [inline]
 unwind_next_frame+0xae/0x2090 arch/x86/kernel/unwind_orc.c:495
 arch_stack_walk+0x94/0xf0 arch/x86/kernel/stacktrace.c:25
 stack_trace_save+0x8e/0xc0 kernel/stacktrace.c:122
 kasan_save_stack+0x30/0x50 mm/kasan/common.c:57
 kasan_save_track+0x14/0x30 mm/kasan/common.c:78
 kasan_save_free_info+0x3b/0x70 mm/kasan/generic.c:584
 poison_slab_object mm/kasan/common.c:253 [inline]
 __kasan_slab_free+0x5f/0x80 mm/kasan/common.c:285
 kasan_slab_free include/linux/kasan.h:235 [inline]
 slab_free_hook mm/slub.c:2748 [inline]
 slab_free mm/slub.c:6499 [inline]
 kfree+0x22b/0x6d0 mm/slub.c:6792
 skb_kfree_head net/core/skbuff.c:1083 [inline]
 skb_free_head+0xb9/0x160 net/core/skbuff.c:1095
 skb_release_data+0x6c5/0x8e0 net/core/skbuff.c:1122
 skb_release_all net/core/skbuff.c:1197 [inline]
 __kfree_skb net/core/skbuff.c:1211 [inline]
 consume_skb net/core/skbuff.c:1448 [inline]
 consume_skb+0xc4/0x110 net/core/skbuff.c:1442
 __unix_dgram_recvmsg+0x754/0xc30 net/unix/af_unix.c:2672
 unix_dgram_recvmsg net/unix/af_unix.c:2689 [inline]
 unix_seqpacket_recvmsg+0x119/0x160 net/unix/af_unix.c:2556
 sock_recvmsg_nosec net/socket.c:1151 [inline]
 sock_recvmsg+0x1d5/0x220 net/socket.c:1173
 sock_read_iter+0x2b0/0x3a0 net/socket.c:1242
 new_sync_read fs/read_write.c:493 [inline]
 vfs_read+0x960/0xb40 fs/read_write.c:574
 ksys_read+0x1f8/0x250 fs/read_write.c:716
 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: 0033:0x7fb4b0488407
Code: 48 89 fa 4c 89 df e8 38 aa 00 00 8b 93 08 03 00 00 59 5e 48 83 f8 fc 74 1a 5b c3 0f 1f 84 00 00 00 00 00 48 8b 44 24 10 0f 05 <5b> c3 0f 1f 80 00 00 00 00 83 e2 39 83 fa 08 75 de e8 23 ff ff ff
RSP: 002b:00007ffe26b252e0 EFLAGS: 00000202 ORIG_RAX: 0000000000000000
RAX: ffffffffffffffda RBX: 00007fb4b03fe780 RCX: 00007fb4b0488407
RDX: 0000000000000408 RSI: 00007ffe26b25330 RDI: 0000000000000007
RBP: 00007ffe26b25a40 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000202 R12: 000055651a7cc5e0
R13: 0000556557637d40 R14: 0000000000000000 R15: 00007ffe26b257f0
 </TASK>
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 e9 c6 1c 23 06 e8 31 09 cf fc eb a0 e8 ba 09 cf
RSP: 0018:ffffc900001379e0 EFLAGS: 00000002
RAX: 0000000000000033 RBX: 00000000000003f8 RCX: 0000000000000000
RDX: 00000000000003f8 RSI: ffffffff85b01965 RDI: ffffffff9bc65ca0
RBP: ffffffff9bc65c60 R08: 0000000000000001 R09: 000000000000001f
R10: 0000000000000000 R11: 6174203a4f464e49 R12: 0000000000000000
R13: 0000000000000033 R14: 0000000000000007 R15: ffffc90000137da8
FS:  0000000000000000(0000) GS:ffff8880d5b5f000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 00007fbba033de9c CR3: 00000000355d2000 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>