INFO: task syz.7.1820:12155 blocked for more than 143 seconds.
Tainted: G L syzkaller #0
"echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message.
task:syz.7.1820 state:D stack:27144 pid:12155 tgid:12155 ppid:11110 task_flags:0x400040 flags:0x00080003
Call Trace:
context_switch kernel/sched/core.c:5510 [inline]
__schedule+0x125c/0x6730 kernel/sched/core.c:7234
__schedule_loop kernel/sched/core.c:7311 [inline]
schedule+0xdd/0x2c0 kernel/sched/core.c:7326
request_wait_answer+0x531/0x840 fs/fuse/dev.c:743
__fuse_request_send fs/fuse/dev.c:757 [inline]
fuse_chan_send+0x58d/0x9a0 fs/fuse/dev.c:833
__fuse_simple_request+0x18e/0x1e0 fs/fuse/req.c:69
fuse_simple_request fs/fuse/fuse_i.h:1012 [inline]
fuse_flush+0x4d6/0x6a0 fs/fuse/file.c:504
filp_flush+0xe7/0x190 fs/open.c:1471
filp_close+0x1c/0x30 fs/open.c:1484
__range_close+0x137/0x7a0 fs/file.c:793
__do_sys_close_range fs/file.c:854 [inline]
__se_sys_close_range fs/file.c:818 [inline]
__x64_sys_close_range+0x3ce/0x5d0 fs/file.c:818
do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline]
do_syscall_64+0x115/0x870 arch/x86/entry/syscall_64.c:94
entry_SYSCALL_64_after_hwframe+0x77/0x7f
RIP: 0033:0x7f719459e0d9
RSP: 002b:00007ffe80a28df8 EFLAGS: 00000246 ORIG_RAX: 00000000000001b4
RAX: ffffffffffffffda RBX: 00007ffe80a28ee0 RCX: 00007f719459e0d9
RDX: 0000000000000000 RSI: 000000000000001e RDI: 0000000000000003
RBP: 0000000000091b7d R08: 0000000000000001 R09: 0000000000000000
R10: 0000001b32520000 R11: 0000000000000246 R12: 00007ffe80a28f20
R13: 00007f719482609c R14: 0000000000091ca8 R15: 00007f7194826090
Showing all locks held in the system:
1 lock held by khungtaskd/31:
#0: ffffffff8ebe8200 (rcu_read_lock){....}-{1:3}, at: rcu_lock_acquire include/linux/rcupdate.h:300 [inline]
#0: ffffffff8ebe8200 (rcu_read_lock){....}-{1:3}, at: rcu_read_lock include/linux/rcupdate.h:840 [inline]
#0: ffffffff8ebe8200 (rcu_read_lock){....}-{1:3}, at: debug_show_all_locks+0x3d/0x184 kernel/locking/lockdep.c:6775
2 locks held by getty/5355:
#0: ffff888037da80a0 (&tty->ldisc_sem){++++}-{0:0}, at: tty_ldisc_ref_wait+0x24/0x80 drivers/tty/tty_ldisc.c:243
#1: ffffc9000322b2e8 (&ldata->atomic_read_lock){+.+.}-{4:4}, at: n_tty_read+0x419/0x14e0 drivers/tty/n_tty.c:2211
5 locks held by kworker/0:6/5724:
#0: ffff888023e9dd40 ((wq_completion)usb_hub_wq){+.+.}-{0:0}, at: process_one_work+0x12b1/0x1940 kernel/workqueue.c:3297
#1: ffffc90004327d08 ((work_completion)(&hub->events)){+.+.}-{0:0}, at: process_one_work+0x988/0x1940 kernel/workqueue.c:3298
#2: ffff88802be771d8 (&dev->mutex){....}-{4:4}, at: device_lock include/linux/device.h:1102 [inline]
#2: ffff88802be771d8 (&dev->mutex){....}-{4:4}, at: hub_event+0x1c0/0x4a60 drivers/usb/core/hub.c:5899
#3: ffff88802be74568 (&port_dev->status_lock){+.+.}-{4:4}, at: usb_lock_port drivers/usb/core/hub.c:3252 [inline]
#3: ffff88802be74568 (&port_dev->status_lock){+.+.}-{4:4}, at: hub_port_connect drivers/usb/core/hub.c:5464 [inline]
#3: ffff88802be74568 (&port_dev->status_lock){+.+.}-{4:4}, at: hub_port_connect_change drivers/usb/core/hub.c:5707 [inline]
#3: ffff88802be74568 (&port_dev->status_lock){+.+.}-{4:4}, at: port_event drivers/usb/core/hub.c:5871 [inline]
#3: ffff88802be74568 (&port_dev->status_lock){+.+.}-{4:4}, at: hub_event+0x2b25/0x4a60 drivers/usb/core/hub.c:5953
#4: ffff88802be0ba60 (hcd->address0_mutex){+.+.}-{4:4}, at: hub_port_connect drivers/usb/core/hub.c:5465 [inline]
#4: ffff88802be0ba60 (hcd->address0_mutex){+.+.}-{4:4}, at: hub_port_connect_change drivers/usb/core/hub.c:5707 [inline]
#4: ffff88802be0ba60 (hcd->address0_mutex){+.+.}-{4:4}, at: port_event drivers/usb/core/hub.c:5871 [inline]
#4: ffff88802be0ba60 (hcd->address0_mutex){+.+.}-{4:4}, at: hub_event+0x2b4e/0x4a60 drivers/usb/core/hub.c:5953
2 locks held by kworker/0:8/5796:
#0: ffff88801bc0b140 ((wq_completion)events){+.+.}-{0:0}, at: process_one_work+0x12b1/0x1940 kernel/workqueue.c:3297
#1: ffffc90004497d08 (free_ipc_work){+.+.}-{0:0}, at: process_one_work+0x988/0x1940 kernel/workqueue.c:3298
3 locks held by kworker/0:2/12214:
#0: ffff88801bc0b140 ((wq_completion)events){+.+.}-{0:0}, at: process_one_work+0x12b1/0x1940 kernel/workqueue.c:3297
#1: ffffc90006ca7d08 ((work_completion)(&data->fib_event_work)){+.+.}-{0:0}, at: process_one_work+0x988/0x1940 kernel/workqueue.c:3298
#2: ffff888077ae3250 (&data->fib_lock){+.+.}-{4:4}, at: nsim_fib_event_work+0x1b8/0x6310 drivers/net/netdevsim/fib.c:1490
2 locks held by syz.3.1850/12239:
#0: ffff888058c2cea0 (&hdev->req_lock){+.+.}-{4:4}, at: hci_dev_do_close+0x26/0xb0 net/bluetooth/hci_core.c:497
#1: ffffffff8ebf3ca8 (rcu_state.exp_mutex){+.+.}-{4:4}, at: exp_funnel_lock+0x19e/0x3c0 kernel/rcu/tree_exp.h:343
3 locks held by kworker/0:3/12407:
#0: ffff88801bc0b140 ((wq_completion)events){+.+.}-{0:0}, at: process_one_work+0x12b1/0x1940 kernel/workqueue.c:3297
#1: ffffc9000cf1fd08 ((work_completion)(&data->fib_event_work)){+.+.}-{0:0}, at: process_one_work+0x988/0x1940 kernel/workqueue.c:3298
#2: ffff888078686250 (&data->fib_lock){+.+.}-{4:4}, at: nsim_fib_event_work+0x1b8/0x6310 drivers/net/netdevsim/fib.c:1490
1 lock held by syz-executor/14942:
#0: ffffffff8ebf3b78 (rcu_state.barrier_mutex){+.+.}-{4:4}, at: rcu_barrier+0x48/0x6d0 kernel/rcu/tree.c:3857
7 locks held by syz-executor/15588:
#0: ffff888026004450 (sb_writers#8){.+.+}-{0:0}, at: ksys_write+0x12a/0x250 fs/read_write.c:739
#1: ffff888054150480 (&of->mutex){+.+.}-{4:4}, at: kernfs_fop_write_iter+0x2c2/0x5f0 fs/kernfs/file.c:336
#2: ffff88802afdd3c8 (kn->active#51){.+.+}-{0:0}, at: kernfs_get_active_of fs/kernfs/file.c:73 [inline]
#2: ffff88802afdd3c8 (kn->active#51){.+.+}-{0:0}, at: kernfs_fop_write_iter+0x332/0x5f0 fs/kernfs/file.c:337
#3: ffffffff900046a0 (nsim_bus_dev_list_lock){+.+.}-{4:4}, at: del_device_store+0xd1/0x480 drivers/net/netdevsim/bus.c:234
#4: ffff8880302f8128 (&dev->mutex){....}-{4:4}, at: device_lock include/linux/device.h:1102 [inline]
#4: ffff8880302f8128 (&dev->mutex){....}-{4:4}, at: __device_driver_lock drivers/base/dd.c:1171 [inline]
#4: ffff8880302f8128 (&dev->mutex){....}-{4:4}, at: device_release_driver_internal+0xb2/0x620 drivers/base/dd.c:1369
#5: ffff8880302fa258 (&devlink->lock_key#13){+.+.}-{4:4}, at: nsim_drv_remove+0x4a/0x1e0 drivers/net/netdevsim/dev.c:1799
#6: ffffffff8ebf3b78 (rcu_state.barrier_mutex){+.+.}-{4:4}, at: rcu_barrier+0x48/0x6d0 kernel/rcu/tree.c:3857
1 lock held by syz.1.2246/15672:
#0: ffff88802e36cea0 (&hdev->req_lock){+.+.}-{4:4}, at: hci_dev_do_close+0x26/0xb0 net/bluetooth/hci_core.c:497
1 lock held by syz.5.2247/15691:
#0: ffffffff8ebf3ca8 (rcu_state.exp_mutex){+.+.}-{4:4}, at: exp_funnel_lock+0x19e/0x3c0 kernel/rcu/tree_exp.h:343
=============================================
NMI backtrace for cpu 0
CPU: 0 UID: 0 PID: 31 Comm: khungtaskd Tainted: G L syzkaller #0 PREEMPT(full)
Tainted: [L]=SOFTLOCKUP
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 07/16/2026
Call Trace:
__dump_stack lib/dump_stack.c:94 [inline]
dump_stack_lvl+0x100/0x190 lib/dump_stack.c:120
nmi_cpu_backtrace.cold+0x12d/0x151 lib/nmi_backtrace.c:122
nmi_trigger_cpumask_backtrace+0x21c/0x2a0 lib/nmi_backtrace.c:65
trigger_all_cpu_backtrace include/linux/nmi.h:162 [inline]
__sys_info lib/sys_info.c:157 [inline]
sys_info+0x141/0x190 lib/sys_info.c:165
check_hung_uninterruptible_tasks kernel/hung_task.c:353 [inline]
watchdog+0xcb1/0x1030 kernel/hung_task.c:561
kthread+0x370/0x450 kernel/kthread.c:436
ret_from_fork+0x72b/0xd50 arch/x86/kernel/process.c:158
ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:245