INFO: task syz-executor:5628 blocked for more than 144 seconds.
Not tainted syzkaller #0
"echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message.
task:syz-executor state:D stack:22424 pid:5628 tgid:5628 ppid:1 task_flags:0x400140 flags:0x00080002
Call Trace:
context_switch kernel/sched/core.c:5388 [inline]
__schedule+0x1821/0x5740 kernel/sched/core.c:7189
__schedule_loop kernel/sched/core.c:7268 [inline]
schedule+0x164/0x360 kernel/sched/core.c:7283
bit_wait+0x11/0xd0 kernel/sched/wait_bit.c:240
__wait_on_bit+0xb9/0x310 kernel/sched/wait_bit.c:52
out_of_line_wait_on_bit+0x13b/0x190 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:1268
gfs2_glock_nq_init fs/gfs2/glock.h:253 [inline]
__gfs2_lookup+0x134/0x2a0 fs/gfs2/inode.c:998
__lookup_slow+0x2b7/0x410 fs/namei.c:1915
lookup_slow+0x53/0x70 fs/namei.c:1932
walk_component fs/namei.c:2278 [inline]
lookup_last fs/namei.c:2785 [inline]
path_lookupat+0x3f5/0x8c0 fs/namei.c:2809
filename_lookup+0x256/0x5d0 fs/namei.c:2838
user_path_at+0x40/0x160 fs/namei.c:3643
ksys_umount fs/namespace.c:2062 [inline]
__do_sys_umount fs/namespace.c:2070 [inline]
__se_sys_umount fs/namespace.c:2068 [inline]
__x64_sys_umount+0xf6/0x170 fs/namespace.c:2068
do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline]
do_syscall_64+0x174/0x580 arch/x86/entry/syscall_64.c:94
entry_SYSCALL_64_after_hwframe+0x77/0x7f
RIP: 0033:0x7f341cf9e097
RSP: 002b:00007ffdce6d4248 EFLAGS: 00000246 ORIG_RAX: 00000000000000a6
RAX: ffffffffffffffda RBX: 00007f341d0321ca RCX: 00007f341cf9e097
RDX: 0000000000000000 RSI: 0000000000000009 RDI: 00007ffdce6d4300
RBP: 00007ffdce6d4300 R08: 0000000000000000 R09: 00000000ffffffff
R10: 0000000000000000 R11: 0000000000000246 R12: 00007ffdce6d53f0
R13: 00007f341d0321ca R14: 0000000000025150 R15: 00007ffdce6d75b0
Showing all locks held in the system:
1 lock held by khungtaskd/31:
#0: ffffffff8e95cd20 (rcu_read_lock){....}-{1:3}, at: rcu_lock_acquire include/linux/rcupdate.h:300 [inline]
#0: ffffffff8e95cd20 (rcu_read_lock){....}-{1:3}, at: rcu_read_lock include/linux/rcupdate.h:838 [inline]
#0: ffffffff8e95cd20 (rcu_read_lock){....}-{1:3}, at: debug_show_all_locks+0x2e/0x180 kernel/locking/lockdep.c:6775
4 locks held by kworker/u8:7/1155:
#0: ffff88801bafe140 ((wq_completion)netns){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:3289 [inline]
#0: ffff88801bafe140 ((wq_completion)netns){+.+.}-{0:0}, at: process_scheduled_works+0xa35/0x1860 kernel/workqueue.c:3397
#1: ffffc9000594fc40 (net_cleanup_work){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:3290 [inline]
#1: ffffc9000594fc40 (net_cleanup_work){+.+.}-{0:0}, at: process_scheduled_works+0xa70/0x1860 kernel/workqueue.c:3397
#2: ffffffff8fdba268 (pernet_ops_rwsem){++++}-{4:4}, at: cleanup_net+0xf4/0x800 net/core/net_namespace.c:673
#3: ffffffff8e963028 (rcu_state.exp_mutex){+.+.}-{4:4}, at: exp_funnel_lock kernel/rcu/tree_exp.h:343 [inline]
#3: ffffffff8e963028 (rcu_state.exp_mutex){+.+.}-{4:4}, at: synchronize_rcu_expedited+0x38d/0x770 kernel/rcu/tree_exp.h:961
2 locks held by getty/5377:
#0: ffff8880323650a0 (&tty->ldisc_sem){++++}-{0:0}, at: tty_ldisc_ref_wait+0x25/0x70 drivers/tty/tty_ldisc.c:243
#1: ffffc900032332e8 (&ldata->atomic_read_lock){+.+.}-{4:4}, at: n_tty_read+0x45c/0x13a0 drivers/tty/n_tty.c:2211
1 lock held by syz-executor/5628:
#0: ffff888050a1f400 (&type->i_mutex_dir_key#20){++++}-{4:4}, at: inode_lock_shared include/linux/fs.h:1044 [inline]
#0: ffff888050a1f400 (&type->i_mutex_dir_key#20){++++}-{4:4}, at: lookup_slow+0x46/0x70 fs/namei.c:1931
7 locks held by kworker/0:3/5630:
4 locks held by kworker/0:6/5778:
#0: ffff8880b863b0e0 (&rq->__lock){-.-.}-{2:2}, at: raw_spin_rq_lock_nested+0xb6/0x150 kernel/sched/core.c:660
#1: ffff8880b8624588 (psi_seq){-.-.}-{0:0}, at: psi_task_switch+0x53/0x880 kernel/sched/psi.c:933
#2: ffffffff8eb25f98 (kernfs_notify_lock){....}-{3:3}, at: spin_lock_irq include/linux/spinlock.h:372 [inline]
#2: ffffffff8eb25f98 (kernfs_notify_lock){....}-{3:3}, at: kernfs_notify_workfn+0x5a5/0x620 fs/kernfs/file.c:919
#3: ffff88801bafd180 (&root->kernfs_rwsem){++++}-{4:4}, at: kernfs_notify_workfn+0x104/0x620 fs/kernfs/file.c:933
1 lock held by syz.0.701/8637:
2 locks held by syz.1.710/8670:
1 lock held by syz.6.711/8676:
#0: ffffffff8e963028 (rcu_state.exp_mutex){+.+.}-{4:4}, at: exp_funnel_lock kernel/rcu/tree_exp.h:311 [inline]
#0: ffffffff8e963028 (rcu_state.exp_mutex){+.+.}-{4:4}, at: synchronize_rcu_expedited+0x2d0/0x770 kernel/rcu/tree_exp.h:961
=============================================
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 05/09/2026
Call Trace:
dump_stack_lvl+0xe8/0x150 lib/dump_stack.c:120
nmi_cpu_backtrace+0x274/0x2d0 lib/nmi_backtrace.c:113
nmi_trigger_cpumask_backtrace+0x17a/0x300 lib/nmi_backtrace.c:62
trigger_all_cpu_backtrace include/linux/nmi.h:162 [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:353 [inline]
watchdog+0xfd3/0x1030 kernel/hung_task.c:561
kthread+0x389/0x470 kernel/kthread.c:436
ret_from_fork+0x514/0xb70 arch/x86/kernel/process.c:158
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: 5630 Comm: kworker/0:3 Not tainted syzkaller #0 PREEMPT(full)
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 05/09/2026
Workqueue: usb_hub_wq hub_event
RIP: 0010:io_serial_out+0x7c/0xc0 drivers/tty/serial/8250/8250_port.c:408
Code: dd 80 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 34 ec fc 41 03 2e 89 d8 89 ea ee <5b> 41 5c 41 5e 41 5f 5d e9 12 67 cb fb cc 44 89 f9 80 e1 07 38 c1
RSP: 0018:ffffc9000203ef90 EFLAGS: 00000006
RAX: 0000000000000000 RBX: 0000000000000000 RCX: 0000000000000000
RDX: 00000000000003f9 RSI: 000000000001573a RDI: 000000000001573b
RBP: 00000000000003f9 R08: 0000000000000003 R09: 0000000000000004
R10: dffffc0000000000 R11: ffffffff8544d970 R12: dffffc0000000000
R13: dffffc0000000000 R14: ffffffff9a78cac0 R15: 0000000000000000
FS: 0000000000000000(0000) GS:ffff8881252a0000(0000) knlGS:0000000000000000
CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 00007ff9907ea2f8 CR3: 000000007203c000 CR4: 0000000000350ef0
Call Trace:
serial_out drivers/tty/serial/8250/8250.h:133 [inline]
serial8250_clear_IER drivers/tty/serial/8250/8250_port.c:-1 [inline]
serial8250_console_write+0x5ae/0x1ba0 drivers/tty/serial/8250/8250_port.c:3325
console_emit_next_record kernel/printk/printk.c:3183 [inline]
console_flush_one_record kernel/printk/printk.c:3269 [inline]
console_flush_all+0x718/0xb20 kernel/printk/printk.c:3343
__console_flush_and_unlock kernel/printk/printk.c:3373 [inline]
console_unlock+0xd1/0x1c0 kernel/printk/printk.c:3413
vprintk_emit+0x485/0x560 kernel/printk/printk.c:2479
dev_vprintk_emit+0x355/0x420 drivers/base/core.c:4930
dev_printk_emit+0xee/0x140 drivers/base/core.c:4941
_dev_info+0x11e/0x180 drivers/base/core.c:4999
hub_port_init+0x5e6/0x28d0 drivers/usb/core/hub.c:4996
hub_port_connect drivers/usb/core/hub.c:5496 [inline]
hub_port_connect_change drivers/usb/core/hub.c:5707 [inline]
port_event drivers/usb/core/hub.c:5871 [inline]
hub_event+0x2593/0x4f30 drivers/usb/core/hub.c:5953
process_one_work kernel/workqueue.c:3314 [inline]
process_scheduled_works+0xb5d/0x1860 kernel/workqueue.c:3397
worker_thread+0xa53/0xfc0 kernel/workqueue.c:3478
kthread+0x389/0x470 kernel/kthread.c:436
ret_from_fork+0x514/0xb70 arch/x86/kernel/process.c:158
ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:245