INFO: task syz.8.3812:22544 blocked for more than 143 seconds.
      Not tainted syzkaller #0
"echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message.
task:syz.8.3812      state:D stack:28360 pid:22544 tgid:22542 ppid:22179  task_flags:0x400040 flags:0x00080002
Call Trace:
 <TASK>
 context_switch kernel/sched/core.c:5257 [inline]
 __schedule+0x14bc/0x5030 kernel/sched/core.c:6864
 __schedule_loop kernel/sched/core.c:6946 [inline]
 schedule+0x165/0x360 kernel/sched/core.c:6961
 schedule_preempt_disabled+0x13/0x30 kernel/sched/core.c:7018
 rwsem_down_write_slowpath+0x872/0xfe0 kernel/locking/rwsem.c:1185
 __down_write_common kernel/locking/rwsem.c:1317 [inline]
 __down_write kernel/locking/rwsem.c:1326 [inline]
 down_write+0x1ab/0x1f0 kernel/locking/rwsem.c:1591
 inode_lock include/linux/fs.h:1027 [inline]
 open_last_lookups fs/namei.c:4506 [inline]
 path_openat+0xabf/0x3d90 fs/namei.c:4753
 do_filp_open+0x1fa/0x410 fs/namei.c:4783
 do_sys_openat2+0x121/0x1c0 fs/open.c:1432
 do_sys_open fs/open.c:1447 [inline]
 __do_sys_open fs/open.c:1455 [inline]
 __se_sys_open fs/open.c:1451 [inline]
 __x64_sys_open+0x11e/0x150 fs/open.c:1451
 do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline]
 do_syscall_64+0xfa/0xfa0 arch/x86/entry/syscall_64.c:94
 entry_SYSCALL_64_after_hwframe+0x77/0x7f
RIP: 0033:0x7f3a8398f749
RSP: 002b:00007f3a8488f038 EFLAGS: 00000246 ORIG_RAX: 0000000000000002
RAX: ffffffffffffffda RBX: 00007f3a83be6090 RCX: 00007f3a8398f749
RDX: 0000000000000000 RSI: 0000000000109042 RDI: 0000200000000080
RBP: 00007f3a83a13f91 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000
R13: 00007f3a83be6128 R14: 00007f3a83be6090 R15: 00007fffa4ac2928
 </TASK>

Showing all locks held in the system:
1 lock held by khungtaskd/31:
 #0: ffffffff8df3d980 (rcu_read_lock){....}-{1:3}, at: rcu_lock_acquire include/linux/rcupdate.h:331 [inline]
 #0: ffffffff8df3d980 (rcu_read_lock){....}-{1:3}, at: rcu_read_lock include/linux/rcupdate.h:867 [inline]
 #0: ffffffff8df3d980 (rcu_read_lock){....}-{1:3}, at: debug_show_all_locks+0x2e/0x180 kernel/locking/lockdep.c:6775
3 locks held by kworker/0:2/796:
 #0: ffff888143aac148 ((wq_completion)usb_hub_wq){+.+.}-{0:0}, at: process_one_work+0x841/0x15e0 kernel/workqueue.c:3236
 #1: ffffc90003927b80 ((work_completion)(&hub->events)
){+.+.}-{0:0}, at: process_one_work+0x868/0x15e0 kernel/workqueue.c:3237
 #2: ffff888028641198 (&dev->mutex){....}-{4:4}, at: device_lock include/linux/device.h:914 [inline]
 #2: ffff888028641198 (&dev->mutex){....}-{4:4}, at: hub_event+0x187/0x4ef0 drivers/usb/core/hub.c:5899
2 locks held by kworker/u8:10/3462:
 #0: ffff8880b863a918 (&rq->__lock){-.-.}-{2:2}, at: raw_spin_rq_lock_nested+0xad/0x140 kernel/sched/core.c:647
 #1: ffffc9000b8efb80 ((work_completion)(&worker->work)){+.+.}-{0:0}, at: process_one_work+0x868/0x15e0 kernel/workqueue.c:3237
2 locks held by getty/5593:
 #0: ffff88814dd6d0a0 (&tty->ldisc_sem){++++}-{0:0}, at: tty_ldisc_ref_wait+0x25/0x70 drivers/tty/tty_ldisc.c:243
 #1: ffffc9000332b2f0 (&ldata->atomic_read_lock){+.+.}-{4:4}, at: n_tty_read+0x43e/0x1400 drivers/tty/n_tty.c:2222
6 locks held by kworker/0:5/5920:
 #0: 
ffff888143aac148 ((wq_completion)usb_hub_wq){+.+.}-{0:0}, at: process_one_work+0x841/0x15e0 kernel/workqueue.c:3236
 #1: ffffc90004b9fb80 ((work_completion)(&hub->events)){+.+.}-{0:0}, at: process_one_work+0x868/0x15e0 kernel/workqueue.c:3237
 #2: ffff888028324198 (&dev->mutex){....}-{4:4}, at: device_lock include/linux/device.h:914 [inline]
 #2: ffff888028324198 (&dev->mutex){....}-{4:4}, at: hub_event+0x187/0x4ef0 drivers/usb/core/hub.c:5899
 #3: ffff888066147198 (&dev->mutex){....}-{4:4}, at: device_lock include/linux/device.h:914 [inline]
 #3: ffff888066147198 (&dev->mutex){....}-{4:4}, at: __device_attach+0x88/0x430 drivers/base/dd.c:1006
 #4: 
ffff88807e375160
 (
&dev->mutex){....}-{4:4}, at: device_lock include/linux/device.h:914 [inline]
&dev->mutex){....}-{4:4}, at: __device_attach+0x88/0x430 drivers/base/dd.c:1006
 #5: ffffffff8dde2e10 (umhelper_sem){++++}-{4:4}, at: usermodehelper_read_trylock+0xf0/0x2b0 kernel/umh.c:214
3 locks held by kworker/u8:18/6257:
 #0: ffff88813fe69948 ((wq_completion)events_unbound#2){+.+.}-{0:0}, at: process_one_work+0x841/0x15e0 kernel/workqueue.c:3236
 #1: ffffc9000b82fb80 ((work_completion)(&map->work)){+.+.}-{0:0}, at: process_one_work+0x868/0x15e0 kernel/workqueue.c:3237
 #2: ffffffff8df43438 (rcu_state.exp_mutex){+.+.}-{4:4}, at: exp_funnel_lock kernel/rcu/tree_exp.h:311 [inline]
 #2: ffffffff8df43438 (rcu_state.exp_mutex){+.+.}-{4:4}, at: synchronize_rcu_expedited+0x2f6/0x730 kernel/rcu/tree_exp.h:957
2 locks held by udevd/15517:
1 lock held by syz-executor/21200:
 #0: ffffffff8df43438 (rcu_state.exp_mutex){+.+.}-{4:4}, at: exp_funnel_lock kernel/rcu/tree_exp.h:343 [inline]
 #0: ffffffff8df43438 (rcu_state.exp_mutex){+.+.}-{4:4}, at: synchronize_rcu_expedited+0x3b9/0x730 kernel/rcu/tree_exp.h:957
4 locks held by udevd/21768:
 #0: ffff88804a2a7b08 (&p->lock){+.+.}-{4:4}, at: seq_read_iter+0xb7/0xe20 fs/seq_file.c:182
 #1: ffff8880647a9088 (&of->mutex#2){+.+.}-{4:4}, at: kernfs_seq_start+0x5c/0x420 fs/kernfs/file.c:172
 #2: 
ffff888047d7ef08 (kn->active#29){++++}-{0:0}, at: kernfs_get_active_of fs/kernfs/file.c:80 [inline]
ffff888047d7ef08 (kn->active#29){++++}-{0:0}, at: kernfs_seq_start+0xb2/0x420 fs/kernfs/file.c:173
 #3: ffff888066147198 (&dev->mutex){....}-{4:4}, at: device_lock_interruptible include/linux/device.h:919 [inline]
 #3: ffff888066147198 (&dev->mutex){....}-{4:4}, at: manufacturer_show+0x26/0xa0 drivers/usb/core/sysfs.c:142
4 locks held by syz.8.3812/22543:
2 locks held by syz.8.3812/22544:
 #0: ffff88807b7d0420 (sb_writers#19){.+.+}-{0:0}, at: mnt_want_write+0x41/0x90 fs/namespace.c:509
 #1: ffff888056362800 (&type->i_mutex_dir_key#16){++++}-{4:4}, at: inode_lock include/linux/fs.h:1027 [inline]
 #1: ffff888056362800 (&type->i_mutex_dir_key#16){++++}-{4:4}, at: open_last_lookups fs/namei.c:4506 [inline]
 #1: ffff888056362800 (&type->i_mutex_dir_key#16){++++}-{4:4}, at: path_openat+0xabf/0x3d90 fs/namei.c:4753
1 lock held by syz.4.4105/23994:

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

NMI backtrace for cpu 1
CPU: 1 UID: 0 PID: 31 Comm: khungtaskd Not tainted syzkaller #0 PREEMPT(full) 
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 10/25/2025
Call Trace:
 <TASK>
 dump_stack_lvl+0x189/0x250 lib/dump_stack.c:120
 nmi_cpu_backtrace+0x39e/0x3d0 lib/nmi_backtrace.c:113
 nmi_trigger_cpumask_backtrace+0x17a/0x300 lib/nmi_backtrace.c:62
 trigger_all_cpu_backtrace include/linux/nmi.h:160 [inline]
 __sys_info lib/sys_info.c:157 [inline]
 sys_info+0x135/0x170 lib/sys_info.c:165
 check_hung_uninterruptible_tasks kernel/hung_task.c:346 [inline]
 watchdog+0xfb5/0x1000 kernel/hung_task.c:515
 kthread+0x711/0x8a0 kernel/kthread.c:463
 ret_from_fork+0x599/0xb30 arch/x86/kernel/process.c:158
 ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:246
 </TASK>
Sending NMI from CPU 1 to CPUs 0:
NMI backtrace for cpu 0
CPU: 0 UID: 0 PID: 21200 Comm: syz-executor Not tainted syzkaller #0 PREEMPT(full) 
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 10/25/2025
RIP: 0010:delay_tsc+0x60/0xc0 arch/x86/lib/delay.c:79
Code: c1 e7 20 49 09 c7 4d 29 f7 49 39 df 73 53 bf 01 00 00 00 e8 a2 b9 36 f6 65 8b 05 4b f1 1b 07 85 c0 74 1c f3 90 bf 01 00 00 00 <e8> db b7 36 f6 e8 e6 7e 01 00 39 c5 75 0e 0f 01 f9 66 90 eb bd e8
RSP: 0018:ffffc90004c9e630 EFLAGS: 00000002
RAX: 0000000000000002 RBX: 0000000000000899 RCX: 0000000000000000
RDX: 0000000000000351 RSI: ffffffff8bbf81c0 RDI: 0000000000000001
RBP: 0000000000000000 R08: ffff888141748237 R09: 1ffff110282e9046
R10: dffffc0000000000 R11: ffffffff8b5a6e90 R12: 1ffffffff336de6a
R13: 00000000ffffffff R14: 000003510ec8ab78 R15: 00000000000007b5
FS:  000055557e033500(0000) GS:ffff888125eba000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 000055555ea655c8 CR3: 00000000556d0000 CR4: 00000000003526f0
Call Trace:
 <TASK>
 udelay include/asm-generic/delay.h:62 [inline]
 wait_for_lsr+0x160/0x2f0 drivers/tty/serial/8250/8250_port.c:1967
 fifo_wait_for_lsr drivers/tty/serial/8250/8250_port.c:3234 [inline]
 serial8250_console_fifo_write drivers/tty/serial/8250/8250_port.c:3257 [inline]
 serial8250_console_write+0x134c/0x1ba0 drivers/tty/serial/8250/8250_port.c:3342
 console_emit_next_record kernel/printk/printk.c:3129 [inline]
 console_flush_one_record kernel/printk/printk.c:3215 [inline]
 console_flush_all+0x745/0xb60 kernel/printk/printk.c:3289
 __console_flush_and_unlock kernel/printk/printk.c:3319 [inline]
 console_unlock+0xbb/0x190 kernel/printk/printk.c:3359
 vprintk_emit+0x4d3/0x5d0 kernel/printk/printk.c:2426
 _printk+0xcf/0x120 kernel/printk/printk.c:2451
 f2fs_printk+0x464/0x500 fs/f2fs/super.c:-1
 f2fs_write_end_io+0x94b/0xc10 fs/f2fs/data.c:357
 __submit_merged_bio+0x256/0x6a0 fs/f2fs/data.c:549
 __f2fs_submit_merged_write fs/f2fs/data.c:644 [inline]
 __submit_merged_write_cond+0x255/0x530 fs/f2fs/data.c:666
 f2fs_submit_merged_write_cond fs/f2fs/data.c:683 [inline]
 f2fs_write_cache_pages fs/f2fs/data.c:3198 [inline]
 __f2fs_write_data_pages fs/f2fs/data.c:3294 [inline]
 f2fs_write_data_pages+0x2756/0x3290 fs/f2fs/data.c:3323
 do_writepages+0x32e/0x550 mm/page-writeback.c:2598
 filemap_writeback mm/filemap.c:387 [inline]
 filemap_fdatawrite_range mm/filemap.c:412 [inline]
 filemap_fdatawrite+0x199/0x240 mm/filemap.c:418
 f2fs_sync_dirty_inodes+0x30f/0x830 fs/f2fs/checkpoint.c:1108
 block_operations fs/f2fs/checkpoint.c:1247 [inline]
 f2fs_write_checkpoint+0x93e/0x2440 fs/f2fs/checkpoint.c:1678
 kill_f2fs_super+0x2cc/0x6d0 fs/f2fs/super.c:5434
 deactivate_locked_super+0xbc/0x130 fs/super.c:474
 cleanup_mnt+0x425/0x4c0 fs/namespace.c:1328
 task_work_run+0x1d4/0x260 kernel/task_work.c:233
 resume_user_mode_work include/linux/resume_user_mode.h:50 [inline]
 __exit_to_user_mode_loop kernel/entry/common.c:44 [inline]
 exit_to_user_mode_loop+0xff/0x4f0 kernel/entry/common.c:75
 __exit_to_user_mode_prepare include/linux/irq-entry-common.h:226 [inline]
 syscall_exit_to_user_mode_prepare include/linux/irq-entry-common.h:256 [inline]
 syscall_exit_to_user_mode_work include/linux/entry-common.h:159 [inline]
 syscall_exit_to_user_mode include/linux/entry-common.h:194 [inline]
 do_syscall_64+0x2e9/0xfa0 arch/x86/entry/syscall_64.c:100
 entry_SYSCALL_64_after_hwframe+0x77/0x7f
RIP: 0033:0x7f526eb90a77
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:00007ffeb4fc47d8 EFLAGS: 00000246 ORIG_RAX: 00000000000000a6
RAX: 0000000000000000 RBX: 00007f526ec13d7d RCX: 00007f526eb90a77
RDX: 0000000000000000 RSI: 0000000000000009 RDI: 00007ffeb4fc4890
RBP: 00007ffeb4fc4890 R08: 0000000000000000 R09: 0000000000000000
R10: 00000000ffffffff R11: 0000000000000246 R12: 00007ffeb4fc5920
R13: 00007f526ec13d7d R14: 00000000001932d0 R15: 00007ffeb4fc5960
 </TASK>