INFO: task kworker/0:2:123 blocked for more than 143 seconds.
Not tainted syzkaller #0
"echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message.
task:kworker/0:2 state:D stack:19704 pid:123 tgid:123 ppid:2 task_flags:0x4288060 flags:0x00080000
Workqueue: usb_hub_wq hub_event
Call Trace:
context_switch kernel/sched/core.c:5583 [inline]
__schedule+0x1325/0x4900 kernel/sched/core.c:7382
__schedule_loop kernel/sched/core.c:7459 [inline]
schedule+0xdd/0x2c0 kernel/sched/core.c:7474
schedule_preempt_disabled+0x13/0x30 kernel/sched/core.c:7531
rwsem_down_write_slowpath+0x4c6/0x12f0 kernel/locking/rwsem.c:1215
__down_write_common kernel/locking/rwsem.c:1347 [inline]
__down_write kernel/locking/rwsem.c:1356 [inline]
down_write+0x1bb/0x1f0 kernel/locking/rwsem.c:1632
usb_deregister_dev+0x7c/0x210 drivers/usb/core/file.c:186
sisusb_disconnect+0x5e/0x200 drivers/usb/misc/sisusbvga/sisusbvga.c:2921
usb_unbind_interface+0x1dd/0x9b0 drivers/usb/core/driver.c:460
device_remove drivers/base/dd.c:619 [inline]
device_remove+0x12a/0x180 drivers/base/dd.c:611
__device_release_driver drivers/base/dd.c:1357 [inline]
device_release_driver_internal+0x441/0x610 drivers/base/dd.c:1380
bus_remove_device+0x2bc/0x560 drivers/base/bus.c:681
device_del+0x376/0x9b0 drivers/base/core.c:3965
usb_disable_device+0x367/0x810 drivers/usb/core/message.c:1484
usb_disconnect+0x2e2/0x9a0 drivers/usb/core/hub.c:2355
hub_port_connect drivers/usb/core/hub.c:5425 [inline]
hub_port_connect_change drivers/usb/core/hub.c:5725 [inline]
port_event drivers/usb/core/hub.c:5889 [inline]
hub_event+0x1d46/0x4510 drivers/usb/core/hub.c:5971
process_one_work+0xac7/0x1b10 kernel/workqueue.c:3495
process_scheduled_works kernel/workqueue.c:3578 [inline]
worker_thread+0x5ef/0xe50 kernel/workqueue.c:3659
kthread+0x373/0x450 kernel/kthread.c:436
ret_from_fork+0x69f/0xc90 arch/x86/kernel/process.c:158
ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:245
Showing all locks held in the system:
locks held by khungtaskd/31: 1, last CPU#0:
#0: ffffffff898e7820 (rcu_read_lock){....}-{1:3}, at: rcu_lock_acquire include/linux/rcupdate.h:309 [inline]
#0: ffffffff898e7820 (rcu_read_lock){....}-{1:3}, at: rcu_read_lock include/linux/rcupdate.h:849 [inline]
#0: ffffffff898e7820 (rcu_read_lock){....}-{1:3}, at: debug_show_all_locks+0x3d/0x184 kernel/locking/lockdep.c:6871
locks held by kworker/0:2/123: 6, on CPU#0:
#0: ffff888105efad48 ((wq_completion)usb_hub_wq){+.+.}-{0:0}, at: process_one_work+0x1461/0x1b10 kernel/workqueue.c:3470
#1: ffffc90001627d18 ((work_completion)(&hub->events)){+.+.}-{0:0}, at: process_one_work+0xa2c/0x1b10 kernel/workqueue.c:3471
#2: ffff88810af011d8 (&dev->mutex){....}-{4:4}, at: device_lock include/linux/device.h:1109 [inline]
#2: ffff88810af011d8 (&dev->mutex){....}-{4:4}, at: hub_event+0x1bb/0x4510 drivers/usb/core/hub.c:5917
#3: ffff8881194e11d8 (&dev->mutex){....}-{4:4}, at: device_lock include/linux/device.h:1109 [inline]
#3: ffff8881194e11d8 (&dev->mutex){....}-{4:4}, at: usb_disconnect+0x10a/0x9a0 drivers/usb/core/hub.c:2346
#4: ffff88810b6cd1a0 (&dev->mutex){....}-{4:4}, at: device_lock include/linux/device.h:1109 [inline]
#4: ffff88810b6cd1a0 (&dev->mutex){....}-{4:4}, at: __device_driver_lock drivers/base/dd.c:1046 [inline]
#4: ffff88810b6cd1a0 (&dev->mutex){....}-{4:4}, at: device_release_driver_internal+0xa7/0x610 drivers/base/dd.c:1377
#5: ffffffff8a576be8 (minor_rwsem#2){++++}-{4:4}, at: usb_deregister_dev+0x7c/0x210 drivers/usb/core/file.c:186
locks held by getty/2923: 2, on CPU#1:
#0: ffff8881126140a0 (&tty->ldisc_sem){++++}-{0:0}, at: tty_ldisc_ref_wait+0x24/0x80 drivers/tty/tty_ldisc.c:243
#1: ffffc900000452e8 (&ldata->atomic_read_lock){+.+.}-{4:4}, at: n_tty_read+0x419/0x1540 drivers/tty/n_tty.c:2211
locks held by udevd/5233: 4, on CPU#0:
#0: ffff8881175fcf38 (&p->lock){+.+.}-{4:4}, at: seq_read_iter+0xe1/0x1270 fs/seq_file.c:183
#1: ffff888120c47880 (&of->mutex#2){+.+.}-{4:4}, at: kernfs_seq_start+0x4f/0x2a0 fs/kernfs/file.c:165
#2: ffff88811409c0f8 (kn->active#11){++++}-{0:0}, at: kernfs_get_active_of fs/kernfs/file.c:73 [inline]
#2: ffff88811409c0f8 (kn->active#11){++++}-{0:0}, at: kernfs_seq_start+0xbc/0x2a0 fs/kernfs/file.c:166
#3: ffff88813b7cc1d8 (&dev->mutex){....}-{4:4}, at: device_lock_interruptible include/linux/device.h:1114 [inline]
#3: ffff88813b7cc1d8 (&dev->mutex){....}-{4:4}, at: manufacturer_show+0x26/0xa0 drivers/usb/core/sysfs.c:142
locks held by udevd/5235: 4, on CPU#1:
#0: ffff88811c849cf8 (&p->lock){+.+.}-{4:4}, at: seq_read_iter+0xe1/0x1270 fs/seq_file.c:183
#1: ffff88810eb0f080 (&of->mutex#2){+.+.}-{4:4}, at: kernfs_seq_start+0x4f/0x2a0 fs/kernfs/file.c:165
#2: ffff888114074d28 (kn->active#11){++++}-{0:0}, at: kernfs_get_active_of fs/kernfs/file.c:73 [inline]
#2: ffff888114074d28 (kn->active#11){++++}-{0:0}, at: kernfs_seq_start+0xbc/0x2a0 fs/kernfs/file.c:166
#3: ffff8881322ea1d8 (&dev->mutex){....}-{4:4}, at: device_lock_interruptible include/linux/device.h:1114 [inline]
#3: ffff8881322ea1d8 (&dev->mutex){....}-{4:4}, at: manufacturer_show+0x26/0xa0 drivers/usb/core/sysfs.c:142
locks held by udevd/5251: 4, on CPU#1:
#0: ffff88811317a2d8 (&p->lock){+.+.}-{4:4}, at: seq_read_iter+0xe1/0x1270 fs/seq_file.c:183
#1: ffff88811b6db480 (&of->mutex#2){+.+.}-{4:4}, at: kernfs_seq_start+0x4f/0x2a0 fs/kernfs/file.c:165
#2: ffff8881135704b8 (kn->active#11){++++}-{0:0}, at: kernfs_get_active_of fs/kernfs/file.c:73 [inline]
#2: ffff8881135704b8 (kn->active#11){++++}-{0:0}, at: kernfs_seq_start+0xbc/0x2a0 fs/kernfs/file.c:166
#3: ffff8881027671d8 (&dev->mutex){....}-{4:4}, at: device_lock_interruptible include/linux/device.h:1114 [inline]
#3: ffff8881027671d8 (&dev->mutex){....}-{4:4}, at: manufacturer_show+0x26/0xa0 drivers/usb/core/sysfs.c:142
locks held by kworker/1:2/8578: 6, on CPU#1:
#0: ffff888105efad48 ((wq_completion)usb_hub_wq){+.+.}-{0:0}, at: process_one_work+0x1461/0x1b10 kernel/workqueue.c:3470
#1: ffffc90014057d18 ((work_completion)(&hub->events)){+.+.}-{0:0}, at: process_one_work+0xa2c/0x1b10 kernel/workqueue.c:3471
#2: ffff888100bea1d8 (&dev->mutex){....}-{4:4}, at: device_lock include/linux/device.h:1109 [inline]
#2: ffff888100bea1d8 (&dev->mutex){....}-{4:4}, at: hub_event+0x1bb/0x4510 drivers/usb/core/hub.c:5917
#3: ffff8881322ea1d8 (&dev->mutex){....}-{4:4}, at: device_lock include/linux/device.h:1109 [inline]
#3: ffff8881322ea1d8 (&dev->mutex){....}-{4:4}, at: __device_attach+0x7e/0x4c0 drivers/base/dd.c:1106
#4: ffff88811368a1a0 (&dev->mutex){....}-{4:4}, at: device_lock include/linux/device.h:1109 [inline]
#4: ffff88811368a1a0 (&dev->mutex){....}-{4:4}, at: __device_attach+0x7e/0x4c0 drivers/base/dd.c:1106
#5: ffffffff8a576be8 (minor_rwsem#2){++++}-{4:4}, at: usb_register_dev+0x11d/0x570 drivers/usb/core/file.c:134
locks held by kworker/1:7/11604: 6, on CPU#1:
#0: ffff888105efad48 ((wq_completion)usb_hub_wq){+.+.}-{0:0}, at: process_one_work+0x1461/0x1b10 kernel/workqueue.c:3470
#1: ffffc90001507d18 ((work_completion)(&hub->events)){+.+.}-{0:0}, at: process_one_work+0xa2c/0x1b10 kernel/workqueue.c:3471
#2: ffff88810afd11d8 (&dev->mutex){....}-{4:4}, at: device_lock include/linux/device.h:1109 [inline]
#2: ffff88810afd11d8 (&dev->mutex){....}-{4:4}, at: hub_event+0x1bb/0x4510 drivers/usb/core/hub.c:5917
#3: ffff8881027671d8 (&dev->mutex){....}-{4:4}, at: device_lock include/linux/device.h:1109 [inline]
#3: ffff8881027671d8 (&dev->mutex){....}-{4:4}, at: __device_attach+0x7e/0x4c0 drivers/base/dd.c:1106
#4: ffff888102f341a0 (&dev->mutex){....}-{4:4}, at: device_lock include/linux/device.h:1109 [inline]
#4: ffff888102f341a0 (&dev->mutex){....}-{4:4}, at: __device_attach+0x7e/0x4c0 drivers/base/dd.c:1106
#5: ffffffff8a576be8 (minor_rwsem#2){++++}-{4:4}, at: usb_register_dev+0x11d/0x570 drivers/usb/core/file.c:134
locks held by kworker/1:5/14574: 7, on CPU#1:
#0: ffff888105efad48 ((wq_completion)usb_hub_wq){+.+.}-{0:0}, at: process_one_work+0x1461/0x1b10 kernel/workqueue.c:3470
#1: ffffc90015b8fd18 ((work_completion)(&hub->events)){+.+.}-{0:0}, at: process_one_work+0xa2c/0x1b10 kernel/workqueue.c:3471
#2: ffff88810ab121d8 (&dev->mutex){....}-{4:4}, at: device_lock include/linux/device.h:1109 [inline]
#2: ffff88810ab121d8 (&dev->mutex){....}-{4:4}, at: hub_event+0x1bb/0x4510 drivers/usb/core/hub.c:5917
#3: ffff888124f911d8 (&dev->mutex){....}-{4:4}, at: device_lock include/linux/device.h:1109 [inline]
#3: ffff888124f911d8 (&dev->mutex){....}-{4:4}, at: __device_attach+0x7e/0x4c0 drivers/base/dd.c:1106
#4: ffff888120de21a0 (&dev->mutex){....}-{4:4}, at: device_lock include/linux/device.h:1109 [inline]
#4: ffff888120de21a0 (&dev->mutex){....}-{4:4}, at: __device_attach+0x7e/0x4c0 drivers/base/dd.c:1106
#5: ffff888117471a58 (&dev->mutex){....}-{4:4}, at: device_lock include/linux/device.h:1109 [inline]
#5: ffff888117471a58 (&dev->mutex){....}-{4:4}, at: __device_attach+0x7e/0x4c0 drivers/base/dd.c:1106
#6: ffffffff8a576be8 (minor_rwsem#2){++++}-{4:4}, at: usb_register_dev+0x11d/0x570 drivers/usb/core/file.c:134
locks held by kworker/0:4/17388: 6, on CPU#0:
#0: ffff888105efad48 ((wq_completion)usb_hub_wq){+.+.}-{0:0}, at: process_one_work+0x1461/0x1b10 kernel/workqueue.c:3470
#1: ffffc90015287d18 ((work_completion)(&hub->events)){+.+.}-{0:0}, at: process_one_work+0xa2c/0x1b10 kernel/workqueue.c:3471
#2: ffff88810938a1d8 (&dev->mutex){....}-{4:4}, at: device_lock include/linux/device.h:1109 [inline]
#2: ffff88810938a1d8 (&dev->mutex){....}-{4:4}, at: hub_event+0x1bb/0x4510 drivers/usb/core/hub.c:5917
#3: ffff88813b7cc1d8 (&dev->mutex){....}-{4:4}, at: device_lock include/linux/device.h:1109 [inline]
#3: ffff88813b7cc1d8 (&dev->mutex){....}-{4:4}, at: __device_attach+0x7e/0x4c0 drivers/base/dd.c:1106
#4: ffff888114cab1a0 (&dev->mutex){....}-{4:4}, at: device_lock include/linux/device.h:1109 [inline]
#4: ffff888114cab1a0 (&dev->mutex){....}-{4:4}, at: __device_attach+0x7e/0x4c0 drivers/base/dd.c:1106
#5: ffffffff8a576be8 (minor_rwsem#2){++++}-{4:4}, at: usb_register_dev+0x11d/0x570 drivers/usb/core/file.c:134
locks held by syz.4.3655/22542: 2, on CPU#1:
#0: ffffffff8a576be8 (minor_rwsem#2){++++}-{4:4}, at: usb_open+0x23/0x220 drivers/usb/core/file.c:38
#1: ffff88811d2370c8 (&(sisusb->lock)){+.+.}-{4:4}, at: sisusb_open+0xb6/0x4b0 drivers/usb/misc/sisusbvga/sisusbvga.c:2213
=============================================
NMI backtrace for cpu 0
CPU: 0 UID: 0 PID: 31 Comm: khungtaskd Not tainted syzkaller #0 PREEMPT(lazy)
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 10/07/2026
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:123
nmi_trigger_cpumask_backtrace+0x21f/0x2a0 lib/nmi_backtrace.c:66
trigger_all_cpu_backtrace include/linux/nmi.h:164 [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:377 [inline]
watchdog+0xd0f/0x10c0 kernel/hung_task.c:598
kthread+0x373/0x450 kernel/kthread.c:436
ret_from_fork+0x69f/0xc90 arch/x86/kernel/process.c:158
ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:245
Sending NMI from CPU 0 to CPUs 1:
NMI backtrace for cpu 1
CPU: 1 UID: 0 PID: 0 Comm: swapper/1 Not tainted syzkaller #0 PREEMPT(lazy)
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 10/07/2026
RIP: 0010:pv_native_safe_halt+0xf/0x20 arch/x86/kernel/paravirt.c:64
Code: 78 ae 01 e9 83 0a 03 00 0f 1f 00 90 90 90 90 90 90 90 90 90 90 90 90 90 90 90 90 f3 0f 1e fa 66 90 0f 00 2d a3 aa 0b 00 fb f4 cc cc cc cc 66 2e 0f 1f 84 00 00 00 00 00 66 90 90 90 90 90 90
RSP: 0018:ffffc9000013fe10 EFLAGS: 00000246
RAX: 00000000022f076f RBX: ffff8881022e9e40 RCX: ffffffff879ae235
RDX: 0000000000000001 RSI: ffffffff893064ce RDI: ffffffff87d36e00
RBP: ffffed102045d3c8 R08: 0000000000000001 R09: ffffed103eae67ad
R10: ffff8881f5733d6b R11: 0000000000000001 R12: 0000000000000000
R13: 0000000000000000 R14: 1ffff92000027fc6 R15: dffffc0000000000
FS: 0000000000000000(0000) GS:ffff888268462000(0000) knlGS:0000000000000000
CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 00007f05a6ee86c0 CR3: 0000000135250000 CR4: 00000000003506f0
Call Trace:
arch_safe_halt arch/x86/include/asm/paravirt.h:62 [inline]
default_idle+0x9/0x10 arch/x86/kernel/process.c:768
default_idle_call+0x6c/0xb0 kernel/sched/idle.c:122
cpuidle_idle_call kernel/sched/idle.c:199 [inline]
do_idle+0x3ae/0x5b0 kernel/sched/idle.c:355
cpu_startup_entry+0x4f/0x60 kernel/sched/idle.c:454
start_secondary+0x21d/0x2d0 arch/x86/kernel/smpboot.c:312
common_startup_64+0x13e/0x158