INFO: task syz.0.23:4568 blocked for more than 143 seconds.
      Not tainted syzkaller #0
"echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message.
task:syz.0.23        state:D stack:24256 pid: 4568 ppid:  4348 flags:0x00004004
Call Trace:
 <TASK>
 context_switch kernel/sched/core.c:5049 [inline]
 __schedule+0x11bb/0x4390 kernel/sched/core.c:6395
 schedule+0x11b/0x1e0 kernel/sched/core.c:6478
 schedule_timeout+0x97/0x280 kernel/time/timer.c:1890
 do_wait_for_common+0x29a/0x440 kernel/sched/completion.c:85
 __wait_for_common kernel/sched/completion.c:106 [inline]
 wait_for_common kernel/sched/completion.c:117 [inline]
 wait_for_completion+0x48/0x60 kernel/sched/completion.c:138
 kthread_stop+0x16e/0x540 kernel/kthread.c:666
 f2fs_stop_gc_thread+0x61/0xa0 fs/f2fs/gc.c:186
 f2fs_ioc_shutdown fs/f2fs/file.c:2308 [inline]
 __f2fs_ioctl+0x6732/0xc370 fs/f2fs/file.c:4221
 vfs_ioctl fs/ioctl.c:51 [inline]
 __do_sys_ioctl fs/ioctl.c:874 [inline]
 __se_sys_ioctl+0xfa/0x170 fs/ioctl.c:860
 do_syscall_x64 arch/x86/entry/common.c:50 [inline]
 do_syscall_64+0x4c/0xa0 arch/x86/entry/common.c:80
 entry_SYSCALL_64_after_hwframe+0x66/0xd0
RIP: 0033:0x7fcad14996c9
RSP: 002b:00007fcad0b08038 EFLAGS: 00000246 ORIG_RAX: 0000000000000010
RAX: ffffffffffffffda RBX: 00007fcad16effa0 RCX: 00007fcad14996c9
RDX: 0000200000000080 RSI: 000000008004587d RDI: 0000000000000004
RBP: 00007fcad151bf91 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000
R13: 00007fcad16f0038 R14: 00007fcad16effa0 R15: 00007ffe06653f28
 </TASK>

Showing all locks held in the system:
2 locks held by kworker/u4:0/9:
1 lock held by khungtaskd/27:
 #0: ffffffff8c11c760 (rcu_read_lock){....}-{1:2}, at: rcu_lock_acquire+0x0/0x30
2 locks held by getty/3958:
 #0: ffff88802c12b098 (&tty->ldisc_sem){++++}-{0:0}, at: tty_ldisc_ref_wait+0x21/0x70 drivers/tty/tty_ldisc.c:252
 #1: ffffc900026562e8 (&ldata->atomic_read_lock){+.+.}-{3:3}, at: n_tty_read+0x5ba/0x1a30 drivers/tty/n_tty.c:2158
3 locks held by kworker/1:7/4290:
 #0: ffff888016870938 ((wq_completion)events){+.+.}-{0:0}, at: process_one_work+0x760/0x1000 kernel/workqueue.c:-1
 #1: ffffc90002effd00 ((work_completion)(&data->fib_event_work)){+.+.}-{0:0}, at: process_one_work+0x7a3/0x1000 kernel/workqueue.c:2285
 #2: ffff888021ddf240 (&data->fib_lock){+.+.}-{3:3}, at: nsim_fib_event_work+0x271/0x3240 drivers/net/netdevsim/fib.c:1480
1 lock held by syz.0.23/4568:
 #0: ffff888023348460 (sb_writers#13){.+.+}-{0:0}, at: mnt_want_write_file+0x5c/0x200 fs/namespace.c:430
1 lock held by syz.1.26/4615:
 #0: ffff88807eb20460 (sb_writers#13){.+.+}-{0:0}, at: mnt_want_write_file+0x5c/0x200 fs/namespace.c:430
1 lock held by syz.2.28/4653:
 #0: ffff88805bcbc460 (sb_writers#13){.+.+}-{0:0}, at: mnt_want_write_file+0x5c/0x200 fs/namespace.c:430
1 lock held by syz.3.29/4680:
 #0: ffff888075eae460 (sb_writers#13){.+.+}-{0:0}, at: mnt_want_write_file+0x5c/0x200 fs/namespace.c:430
1 lock held by syz.4.31/4715:
 #0: ffff88801e9f8460 (sb_writers#13){.+.+}-{0:0}, at: mnt_want_write_file+0x5c/0x200 fs/namespace.c:430
1 lock held by syz.5.33/4765:
 #0: ffff888060f2a460 (sb_writers#13){.+.+}-{0:0}, at: mnt_want_write_file+0x5c/0x200 fs/namespace.c:430
1 lock held by syz.6.35/4805:
 #0: ffff8880243fe460 (sb_writers#13){.+.+}-{0:0}, at: mnt_want_write_file+0x5c/0x200 fs/namespace.c:430
1 lock held by syz.7.36/4834:
 #0: ffff888020338460 (sb_writers#13){.+.+}-{0:0}, at: mnt_want_write_file+0x5c/0x200 fs/namespace.c:430
1 lock held by syz.8.38/4885:
 #0: ffff88807d8ce460 (sb_writers#13){.+.+}-{0:0}, at: mnt_want_write_file+0x5c/0x200 fs/namespace.c:430
1 lock held by syz.9.40/4924:
 #0: ffff88802d08e460 (sb_writers#13){.+.+}-{0:0}, at: mnt_want_write_file+0x5c/0x200 fs/namespace.c:430

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

NMI backtrace for cpu 1
CPU: 1 PID: 27 Comm: khungtaskd Not tainted syzkaller #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 10/02/2025
Call Trace:
 <TASK>
 dump_stack_lvl+0x168/0x230 lib/dump_stack.c:106
 nmi_cpu_backtrace+0x397/0x3d0 lib/nmi_backtrace.c:111
 nmi_trigger_cpumask_backtrace+0x163/0x280 lib/nmi_backtrace.c:62
 trigger_all_cpu_backtrace include/linux/nmi.h:148 [inline]
 check_hung_uninterruptible_tasks kernel/hung_task.c:212 [inline]
 watchdog+0xe0f/0xe50 kernel/hung_task.c:369
 kthread+0x436/0x520 kernel/kthread.c:334
 ret_from_fork+0x1f/0x30 arch/x86/entry/entry_64.S:287
 </TASK>
Sending NMI from CPU 1 to CPUs 0:
NMI backtrace for cpu 0
CPU: 0 PID: 3544 Comm: syslogd Not tainted syzkaller #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 10/02/2025
RIP: 0010:__lock_acquire+0x5a45/0x7c60 kernel/locking/lockdep.c:5039
Code: 00 00 42 c6 44 00 1b 00 65 48 8b 04 25 28 00 00 00 48 3b 84 24 00 02 00 00 0f 85 f0 0b 00 00 8b 44 24 68 48 8d 65 d8 5b 41 5c <41> 5d 41 5e 41 5f 5d c3 31 db 45 31 e4 45 31 ff 48 c7 c0 60 3b 0b
RSP: 0018:ffffc9000dd47718 EFLAGS: 00000046
RAX: 0000000000000001 RBX: 0000000000000000 RCX: ffffffff815c1200
RDX: 0000000000000000 RSI: 0000000000000008 RDI: ffffffff8ffbe168
RBP: ffffc9000dd47730 R08: dffffc0000000000 R09: fffffbfff1ff7c2e
R10: fffffbfff1ff7c2e R11: 1ffffffff1ff7c2d R12: ffff88802c31b1e0
R13: ffff88807efbd940 R14: ffff88807efbe420 R15: ffff88807efbe478
FS:  00007f5f37f02c80(0000) GS:ffff8880b9000000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 00007fef25a9df98 CR3: 000000002a9ba000 CR4: 00000000003506f0
DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400
Call Trace:
 <TASK>
 lock_acquire+0x197/0x3f0 kernel/locking/lockdep.c:5623
 __raw_spin_lock_irqsave include/linux/spinlock_api_smp.h:110 [inline]
 _raw_spin_lock_irqsave+0xa4/0xf0 kernel/locking/spinlock.c:162
 __skb_try_recv_datagram+0x147/0x4d0 net/core/datagram.c:264
 __unix_dgram_recvmsg+0x20f/0xd50 net/unix/af_unix.c:2315
 sock_recvmsg_nosec net/socket.c:968 [inline]
 sock_recvmsg net/socket.c:986 [inline]
 sock_read_iter+0x2a2/0x340 net/socket.c:1067
 call_read_iter include/linux/fs.h:2167 [inline]
 new_sync_read fs/read_write.c:404 [inline]
 vfs_read+0x725/0xcf0 fs/read_write.c:485
 ksys_read+0x14d/0x250 fs/read_write.c:623
 do_syscall_x64 arch/x86/entry/common.c:50 [inline]
 do_syscall_64+0x4c/0xa0 arch/x86/entry/common.c:80
 entry_SYSCALL_64_after_hwframe+0x66/0xd0
RIP: 0033:0x7f5f38052407
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:00007ffded5fb1a0 EFLAGS: 00000202 ORIG_RAX: 0000000000000000
RAX: ffffffffffffffda RBX: 00007f5f37f02c80 RCX: 00007f5f38052407
RDX: 00000000000000ff RSI: 000056515719a950 RDI: 0000000000000000
RBP: 000056515719a910 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000202 R12: 000056515719a9a1
R13: 0000000000000000 R14: 000056515719a950 R15: 0000565144390d98
 </TASK>