INFO: task syz-executor:5866 blocked for more than 143 seconds.
      Not tainted syzkaller #0
"echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message.
task:syz-executor    state:D stack:21928 pid:5866  tgid:5866  ppid:1      task_flags:0x400140 flags:0x00004004
Call Trace:
 <TASK>
 context_switch kernel/sched/core.c:5357 [inline]
 __schedule+0x1798/0x4cc0 kernel/sched/core.c:6961
 __schedule_loop kernel/sched/core.c:7043 [inline]
 schedule+0x165/0x360 kernel/sched/core.c:7058
 bit_wait+0x11/0xd0 kernel/sched/wait_bit.c:240
 __wait_on_bit+0xb6/0x310 kernel/sched/wait_bit.c:52
 out_of_line_wait_on_bit+0x123/0x170 kernel/sched/wait_bit.c:67
 wait_on_bit include/linux/wait_bit.h:77 [inline]
 gfs2_glock_wait+0xbd/0x2a0 fs/gfs2/glock.c:1335
 gfs2_glock_nq_init fs/gfs2/glock.h:252 [inline]
 __gfs2_lookup+0x117/0x270 fs/gfs2/inode.c:984
 __lookup_slow+0x297/0x3d0 fs/namei.c:1808
 lookup_slow+0x53/0x70 fs/namei.c:1825
 walk_component+0x2d2/0x400 fs/namei.c:2129
 lookup_last fs/namei.c:2630 [inline]
 path_lookupat+0x163/0x430 fs/namei.c:2654
 filename_lookup+0x212/0x570 fs/namei.c:2683
 user_path_at+0x3a/0x60 fs/namei.c:3127
 ksys_umount fs/namespace.c:2112 [inline]
 __do_sys_umount fs/namespace.c:2120 [inline]
 __se_sys_umount fs/namespace.c:2118 [inline]
 __x64_sys_umount+0xee/0x160 fs/namespace.c:2118
 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: 0033:0x7fc094d8ff17
RSP: 002b:00007fff54195ee8 EFLAGS: 00000246 ORIG_RAX: 00000000000000a6
RAX: ffffffffffffffda RBX: 00007fc094e11c05 RCX: 00007fc094d8ff17
RDX: 0000000000000000 RSI: 0000000000000009 RDI: 00007fff54195fa0
RBP: 00007fff54195fa0 R08: 0000000000000000 R09: 0000000000000000
R10: 00000000ffffffff R11: 0000000000000246 R12: 00007fff54197090
R13: 00007fc094e11c05 R14: 000000000002325d R15: 00007fff54199250
 </TASK>
INFO: lockdep is turned off.
NMI backtrace for cpu 0
CPU: 0 UID: 0 PID: 31 Comm: khungtaskd Not tainted syzkaller #0 PREEMPT(full) 
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 07/12/2025
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]
 check_hung_uninterruptible_tasks kernel/hung_task.c:332 [inline]
 watchdog+0xf60/0xfa0 kernel/hung_task.c:495
 kthread+0x711/0x8a0 kernel/kthread.c:463
 ret_from_fork+0x47c/0x820 arch/x86/kernel/process.c:148
 ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:245
 </TASK>
Sending NMI from CPU 0 to CPUs 1:
NMI backtrace for cpu 1
CPU: 1 UID: 0 PID: 980 Comm: kworker/1:2 Not tainted syzkaller #0 PREEMPT(full) 
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 07/12/2025
Workqueue: usb_hub_wq hub_event
RIP: 0010:io_serial_out+0x7c/0xc0 drivers/tty/serial/8250/8250_port.c:407
Code: 6d 6d 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 fc 16 d1 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:ffffc90003a6ee30 EFLAGS: 00000002
RAX: 0000000000000030 RBX: 0000000000000030 RCX: 0000000000000000
RDX: 00000000000003f8 RSI: 00000000000163c4 RDI: 00000000000163c5
RBP: 00000000000003f8 R08: ffff888024778237 R09: 1ffff110048ef046
R10: dffffc0000000000 R11: ffffffff85532130 R12: dffffc0000000000
R13: ffffffff99d168c6 R14: ffffffff9a00af20 R15: 0000000000000000
FS:  0000000000000000(0000) GS:ffff888125aff000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 0000555562dab608 CR3: 0000000072e9e000 CR4: 00000000003526f0
DR0: 0000040000000000 DR1: 000000000000064f DR2: 0000000000000006
DR3: 0000000000000006 DR6: 00000000ffff0ff0 DR7: 0000000000000400
Call Trace:
 <TASK>
 serial_port_out include/linux/serial_core.h:811 [inline]
 serial8250_console_putchar drivers/tty/serial/8250/8250_port.c:3192 [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:3342
 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_err+0x10a/0x160 drivers/base/core.c:4980
 hub_port_init+0x1f95/0x2800 drivers/usb/core/hub.c:5170
 hub_port_connect drivers/usb/core/hub.c:5495 [inline]
 hub_port_connect_change drivers/usb/core/hub.c:5706 [inline]
 port_event drivers/usb/core/hub.c:5870 [inline]
 hub_event+0x2532/0x4a20 drivers/usb/core/hub.c:5952
 process_one_work kernel/workqueue.c:3236 [inline]
 process_scheduled_works+0xae1/0x17b0 kernel/workqueue.c:3319
 worker_thread+0x8a0/0xda0 kernel/workqueue.c:3400
 kthread+0x711/0x8a0 kernel/kthread.c:463
 ret_from_fork+0x47c/0x820 arch/x86/kernel/process.c:148
 ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:245
 </TASK>