INFO: task syz.0.9209:6148 blocked for more than 143 seconds.
Not tainted 6.16.0-rc5-next-20250711-syzkaller #0
"echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message.
task:syz.0.9209 state:D stack:28712 pid:6148 tgid:6142 ppid:1455 task_flags:0x400140 flags:0x00004004
Call Trace:
context_switch kernel/sched/core.c:5314 [inline]
__schedule+0x16f5/0x4d00 kernel/sched/core.c:6697
__schedule_loop kernel/sched/core.c:6775 [inline]
schedule+0x165/0x360 kernel/sched/core.c:6790
schedule_preempt_disabled+0x13/0x30 kernel/sched/core.c:6847
rwsem_down_write_slowpath+0xbec/0x1030 kernel/locking/rwsem.c:1187
__down_write_common kernel/locking/rwsem.c:1319 [inline]
__down_write kernel/locking/rwsem.c:1328 [inline]
down_write_nested+0x1b5/0x200 kernel/locking/rwsem.c:1709
inode_lock_nested include/linux/fs.h:914 [inline]
filename_create+0x1f8/0x3c0 fs/namei.c:4139
do_symlinkat+0xbc/0x3f0 fs/namei.c:4749
__do_sys_symlink fs/namei.c:4777 [inline]
__se_sys_symlink fs/namei.c:4775 [inline]
__x64_sys_symlink+0x7a/0x90 fs/namei.c:4775
do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline]
do_syscall_64+0xfa/0x3b0 arch/x86/entry/syscall_64.c:94
entry_SYSCALL_64_after_hwframe+0x77/0x7f
RIP: 0033:0x7f5f2258e929
RSP: 002b:00007f5f23470038 EFLAGS: 00000246 ORIG_RAX: 0000000000000058
RAX: ffffffffffffffda RBX: 00007f5f227b6080 RCX: 00007f5f2258e929
RDX: 0000000000000000 RSI: 0000200000000040 RDI: 0000200000000000
RBP: 00007f5f22610b39 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000
R13: 0000000000000001 R14: 00007f5f227b6080 R15: 00007ffcce276e58
Showing all locks held in the system:
1 lock held by khungtaskd/31:
#0: ffffffff8e53c5a0 (rcu_read_lock){....}-{1:3}, at: rcu_lock_acquire include/linux/rcupdate.h:331 [inline]
#0: ffffffff8e53c5a0 (rcu_read_lock){....}-{1:3}, at: rcu_read_lock include/linux/rcupdate.h:841 [inline]
#0: ffffffff8e53c5a0 (rcu_read_lock){....}-{1:3}, at: debug_show_all_locks+0x2e/0x180 kernel/locking/lockdep.c:6770
2 locks held by getty/5617:
#0: ffff88814e0900a0 (&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/0:11/2212:
#0: ffff8881416ba948 ((wq_completion)usb_hub_wq){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:3214 [inline]
#0: ffff8881416ba948 ((wq_completion)usb_hub_wq){+.+.}-{0:0}, at: process_scheduled_works+0x9b4/0x17b0 kernel/workqueue.c:3322
#1: ffffc9000bf17bc0 ((work_completion)(&hub->events)){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:3215 [inline]
#1: ffffc9000bf17bc0 ((work_completion)(&hub->events)){+.+.}-{0:0}, at: process_scheduled_works+0x9ef/0x17b0 kernel/workqueue.c:3322
#2: ffff888145749198 (&dev->mutex){....}-{4:4}, at: device_lock include/linux/device.h:911 [inline]
#2: ffff888145749198 (&dev->mutex){....}-{4:4}, at: hub_event+0x184/0x4a00 drivers/usb/core/hub.c:5894
#3: ffff88814574c518 (&port_dev->status_lock){+.+.}-{4:4}, at: usb_lock_port drivers/usb/core/hub.c:3251 [inline]
#3: ffff88814574c518 (&port_dev->status_lock){+.+.}-{4:4}, at: hub_port_connect drivers/usb/core/hub.c:5463 [inline]
#3: ffff88814574c518 (&port_dev->status_lock){+.+.}-{4:4}, at: hub_port_connect_change drivers/usb/core/hub.c:5706 [inline]
#3: ffff88814574c518 (&port_dev->status_lock){+.+.}-{4:4}, at: port_event drivers/usb/core/hub.c:5866 [inline]
#3: ffff88814574c518 (&port_dev->status_lock){+.+.}-{4:4}, at: hub_event+0x21a3/0x4a00 drivers/usb/core/hub.c:5948
#4: ffff88814570f768 (hcd->address0_mutex){+.+.}-{4:4}, at: hub_port_connect drivers/usb/core/hub.c:5464 [inline]
#4: ffff88814570f768 (hcd->address0_mutex){+.+.}-{4:4}, at: hub_port_connect_change drivers/usb/core/hub.c:5706 [inline]
#4: ffff88814570f768 (hcd->address0_mutex){+.+.}-{4:4}, at: port_event drivers/usb/core/hub.c:5866 [inline]
#4: ffff88814570f768 (hcd->address0_mutex){+.+.}-{4:4}, at: hub_event+0x21cb/0x4a00 drivers/usb/core/hub.c:5948
#5: ffffffff8f1f5830 (ehci_cf_port_reset_rwsem){.+.+}-{4:4}, at: hub_port_reset+0x163/0x1750 drivers/usb/core/hub.c:3066
2 locks held by syz.0.9209/6143:
#0: ffff88806b79e428 (sb_writers#29){.+.+}-{0:0}, at: mnt_want_write+0x41/0x90 fs/namespace.c:557
#1: ffff88804d07ae58 (&type->i_mutex_dir_key#12){++++}-{4:4}, at: inode_lock include/linux/fs.h:869 [inline]
#1: ffff88804d07ae58 (&type->i_mutex_dir_key#12){++++}-{4:4}, at: vfs_utimes+0x396/0x570 fs/utimes.c:65
2 locks held by syz.0.9209/6148:
#0: ffff88806b79e428 (sb_writers#29){.+.+}-{0:0}, at: mnt_want_write+0x41/0x90 fs/namespace.c:557
#1: ffff88804d07ae58 (&type->i_mutex_dir_key#12
/1
){+.+.}-{4:4}, at: inode_lock_nested include/linux/fs.h:914 [inline]
){+.+.}-{4:4}, at: filename_create+0x1f8/0x3c0 fs/namei.c:4139
=============================================
NMI backtrace for cpu 1
CPU: 1 UID: 0 PID: 31 Comm: khungtaskd Not tainted 6.16.0-rc5-next-20250711-syzkaller #0 PREEMPT(full)
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 05/07/2025
Call Trace:
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]
check_hung_uninterruptible_tasks kernel/hung_task.c:328 [inline]
watchdog+0xfee/0x1030 kernel/hung_task.c:491
kthread+0x711/0x8a0 kernel/kthread.c:463
ret_from_fork+0x3f9/0x770 arch/x86/kernel/process.c:148
ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:245
Sending NMI from CPU 1 to CPUs 0:
NMI backtrace for cpu 0
CPU: 0 UID: 0 PID: 2212 Comm: kworker/0:11 Not tainted 6.16.0-rc5-next-20250711-syzkaller #0 PREEMPT(full)
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 05/07/2025
Workqueue: usb_hub_wq hub_event
RIP: 0010:io_serial_out+0x7c/0xc0 drivers/tty/serial/8250/8250_port.c:407
Code: d4 6a fc 44 89 f9 d3 e5 49 83 c6 40 4c 89 f0 48 c1 e8 03 42 80 3c 20 00 74 08 4c 89 f7 e8 cc 8a cf 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:ffffc9000bf16dd0 EFLAGS: 00000002
RAX: 000000000000005d RBX: 000000000000005d RCX: 0000000000000000
RDX: 00000000000003f8 RSI: 00000000000fffff RDI: 0000000000100000
RBP: 00000000000003f8 R08: ffff8880246a0237 R09: 1ffff110048d4046
R10: dffffc0000000000 R11: ffffffff855532f0 R12: dffffc0000000000
R13: ffffffff99f868ee R14: ffffffff9a28baa0 R15: 0000000000000000
FS: 0000000000000000(0000) GS:ffff88812578f000(0000) knlGS:0000000000000000
CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 00007ff0e3582178 CR3: 0000000033b6e000 CR4: 00000000003526f0
DR0: 0000000000000004 DR1: 0000000000000006 DR2: 0000000000000004
DR3: 0000000000001000 DR6: 00000000ffff0ff0 DR7: 0000000000000400
Call Trace:
serial_port_out include/linux/serial_core.h:798 [inline]
serial8250_console_putchar drivers/tty/serial/8250/8250_port.c:3246 [inline]
serial8250_console_fifo_write drivers/tty/serial/8250/8250_port.c:-1 [inline]
serial8250_console_write+0x140d/0x1ba0 drivers/tty/serial/8250/8250_port.c:3396
console_emit_next_record kernel/printk/printk.c:3138 [inline]
console_flush_all+0x725/0xc40 kernel/printk/printk.c:3226
__console_flush_and_unlock kernel/printk/printk.c:3285 [inline]
console_unlock+0xc4/0x270 kernel/printk/printk.c:3325
vprintk_emit+0x5b7/0x7a0 kernel/printk/printk.c:2450
dev_vprintk_emit+0x337/0x3f0 drivers/base/core.c:4914
dev_printk_emit+0xe0/0x130 drivers/base/core.c:4925
_dev_info+0x10a/0x160 drivers/base/core.c:4983
announce_device+0x117/0x2c0 drivers/usb/core/hub.c:2412
usb_new_device+0x4ef/0x16f0 drivers/usb/core/hub.c:2675
hub_port_connect drivers/usb/core/hub.c:5566 [inline]
hub_port_connect_change drivers/usb/core/hub.c:5706 [inline]
port_event drivers/usb/core/hub.c:5866 [inline]
hub_event+0x2941/0x4a00 drivers/usb/core/hub.c:5948
process_one_work kernel/workqueue.c:3239 [inline]
process_scheduled_works+0xade/0x17b0 kernel/workqueue.c:3322
worker_thread+0x8a0/0xda0 kernel/workqueue.c:3403
kthread+0x711/0x8a0 kernel/kthread.c:463
ret_from_fork+0x3f9/0x770 arch/x86/kernel/process.c:148
ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:245