INFO: task kworker/1:4:21060 blocked for more than 143 seconds.
Not tainted syzkaller #0
"echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message.
task:kworker/1:4 state:D stack:21672 pid:21060 tgid:21060 ppid:2 task_flags:0x4208060 flags:0x00080000
Workqueue: usb_hub_wq hub_event
Call Trace:
context_switch kernel/sched/core.c:5325 [inline]
__schedule+0x1190/0x5de0 kernel/sched/core.c:6929
__schedule_loop kernel/sched/core.c:7011 [inline]
schedule+0xe7/0x3a0 kernel/sched/core.c:7026
schedule_timeout+0x257/0x290 kernel/time/sleep_timeout.c:75
do_wait_for_common kernel/sched/completion.c:100 [inline]
__wait_for_common+0x2fc/0x4e0 kernel/sched/completion.c:121
i2c_del_adapter+0x546/0x6f0 drivers/i2c/i2c-core-base.c:1814
dvb_usbv2_i2c_exit drivers/media/usb/dvb-usb-v2/dvb_usb_core.c:86 [inline]
dvb_usbv2_exit.isra.0+0x45b/0x9f0 drivers/media/usb/dvb-usb-v2/dvb_usb_core.c:844
dvb_usbv2_probe+0x1f61/0x3e50 drivers/media/usb/dvb-usb-v2/dvb_usb_core.c:993
usb_probe_interface+0x300/0xa40 drivers/usb/core/driver.c:396
call_driver_probe drivers/base/dd.c:581 [inline]
really_probe+0x23e/0xa90 drivers/base/dd.c:659
__driver_probe_device+0x1de/0x440 drivers/base/dd.c:801
driver_probe_device+0x4c/0x1b0 drivers/base/dd.c:831
__device_attach_driver+0x1df/0x310 drivers/base/dd.c:959
bus_for_each_drv+0x156/0x1e0 drivers/base/bus.c:462
__device_attach+0x1e4/0x4b0 drivers/base/dd.c:1031
bus_probe_device+0x17f/0x1c0 drivers/base/bus.c:537
device_add+0x1148/0x1aa0 drivers/base/core.c:3689
usb_set_configuration+0x1187/0x1e20 drivers/usb/core/message.c:2210
usb_generic_driver_probe+0xb1/0x110 drivers/usb/core/generic.c:250
usb_probe_device+0xec/0x3e0 drivers/usb/core/driver.c:291
call_driver_probe drivers/base/dd.c:581 [inline]
really_probe+0x23e/0xa90 drivers/base/dd.c:659
__driver_probe_device+0x1de/0x440 drivers/base/dd.c:801
driver_probe_device+0x4c/0x1b0 drivers/base/dd.c:831
__device_attach_driver+0x1df/0x310 drivers/base/dd.c:959
bus_for_each_drv+0x156/0x1e0 drivers/base/bus.c:462
__device_attach+0x1e4/0x4b0 drivers/base/dd.c:1031
bus_probe_device+0x17f/0x1c0 drivers/base/bus.c:537
device_add+0x1148/0x1aa0 drivers/base/core.c:3689
usb_new_device+0xd07/0x1a60 drivers/usb/core/hub.c:2694
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:5870 [inline]
hub_event+0x2f34/0x4fe0 drivers/usb/core/hub.c:5952
process_one_work+0x9cf/0x1b70 kernel/workqueue.c:3263
process_scheduled_works kernel/workqueue.c:3346 [inline]
worker_thread+0x6c8/0xf10 kernel/workqueue.c:3427
kthread+0x3c5/0x780 kernel/kthread.c:463
ret_from_fork+0x56a/0x730 arch/x86/kernel/process.c:148
ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:245
INFO: task syz.6.9313:6232 blocked for more than 144 seconds.
Not tainted syzkaller #0
"echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message.
task:syz.6.9313 state:D stack:27064 pid:6232 tgid:6231 ppid:350 task_flags:0x400040 flags:0x00080002
Call Trace:
context_switch kernel/sched/core.c:5325 [inline]
__schedule+0x1190/0x5de0 kernel/sched/core.c:6929
__schedule_loop kernel/sched/core.c:7011 [inline]
schedule+0xe7/0x3a0 kernel/sched/core.c:7026
schedule_preempt_disabled+0x13/0x30 kernel/sched/core.c:7083
__mutex_lock_common kernel/locking/mutex.c:676 [inline]
__mutex_lock+0x818/0x1060 kernel/locking/mutex.c:760
device_lock include/linux/device.h:914 [inline]
usbdev_open+0x1b6/0x8b0 drivers/usb/core/devio.c:1054
chrdev_open+0x234/0x6a0 fs/char_dev.c:414
do_dentry_open+0x982/0x1530 fs/open.c:965
vfs_open+0x82/0x3f0 fs/open.c:1095
do_open fs/namei.c:3975 [inline]
path_openat+0x1de4/0x2cb0 fs/namei.c:4134
do_filp_open+0x20b/0x470 fs/namei.c:4161
do_sys_openat2+0x11b/0x1d0 fs/open.c:1435
do_sys_open fs/open.c:1450 [inline]
__do_sys_openat fs/open.c:1466 [inline]
__se_sys_openat fs/open.c:1461 [inline]
__x64_sys_openat+0x174/0x210 fs/open.c:1461
do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline]
do_syscall_64+0xcd/0x4e0 arch/x86/entry/syscall_64.c:94
entry_SYSCALL_64_after_hwframe+0x77/0x7f
RIP: 0033:0x7f785678d710
RSP: 002b:00007f78549edb70 EFLAGS: 00000293 ORIG_RAX: 0000000000000101
RAX: ffffffffffffffda RBX: 0000000000008401 RCX: 00007f785678d710
RDX: 0000000000008401 RSI: 00007f78549edc10 RDI: 00000000ffffff9c
RBP: 00007f78549edc10 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000293 R12: cccccccccccccccd
R13: 00007f78569e6038 R14: 00007f78569e5fa0 R15: 00007fff91070d88
Showing all locks held in the system:
4 locks held by rcu_exp_gp_kthr/18:
#0: ffff8880b863a318 (&rq->__lock){-.-.}-{2:2}, at: raw_spin_rq_lock_nested kernel/sched/core.c:646 [inline]
#0: ffff8880b863a318 (&rq->__lock){-.-.}-{2:2}, at: raw_spin_rq_lock_nested+0x7e/0x130 kernel/sched/core.c:631
#1: ffff8880b8624088 (psi_seq){-.-.}-{0:0}, at: psi_sched_switch kernel/sched/stats.h:220 [inline]
#1: ffff8880b8624088 (psi_seq){-.-.}-{0:0}, at: __schedule+0x1861/0x5de0 kernel/sched/core.c:6923
#2: ffff88803659aee8 (&p->pi_lock){-.-.}-{2:2}, at: class_raw_spinlock_irqsave_constructor include/linux/spinlock.h:557 [inline]
#2: ffff88803659aee8 (&p->pi_lock){-.-.}-{2:2}, at: try_to_wake_up+0xb7/0x1870 kernel/sched/core.c:4181
#3: ffff8880b863a318 (&rq->__lock){-.-.}-{2:2}, at: raw_spin_rq_lock_nested kernel/sched/core.c:646 [inline]
#3: ffff8880b863a318 (&rq->__lock){-.-.}-{2:2}, at: raw_spin_rq_lock_nested+0x7e/0x130 kernel/sched/core.c:631
1 lock held by khungtaskd/31:
#0: ffffffff8e1c3620 (rcu_read_lock){....}-{1:3}, at: rcu_lock_acquire include/linux/rcupdate.h:331 [inline]
#0: ffffffff8e1c3620 (rcu_read_lock){....}-{1:3}, at: rcu_read_lock include/linux/rcupdate.h:841 [inline]
#0: ffffffff8e1c3620 (rcu_read_lock){....}-{1:3}, at: debug_show_all_locks+0x36/0x1c0 kernel/locking/lockdep.c:6775
2 locks held by getty/5583:
#0: ffff88814d9ca0a0 (&tty->ldisc_sem){++++}-{0:0}, at: tty_ldisc_ref_wait+0x24/0x80 drivers/tty/tty_ldisc.c:243
#1: ffffc9000332b2f0 (&ldata->atomic_read_lock){+.+.}-{4:4}, at: n_tty_read+0x41b/0x14f0 drivers/tty/n_tty.c:2222
5 locks held by kworker/1:4/21060:
#0: ffff888022689d48 ((wq_completion)usb_hub_wq){+.+.}-{0:0}, at: process_one_work+0x12a2/0x1b70 kernel/workqueue.c:3238
#1: ffffc900048dfd10 ((work_completion)(&hub->events)){+.+.}-{0:0}, at: process_one_work+0x929/0x1b70 kernel/workqueue.c:3239
#2: ffff88802912d198 (&dev->mutex){....}-{4:4}, at: device_lock include/linux/device.h:914 [inline]
#2: ffff88802912d198 (&dev->mutex){....}-{4:4}, at: hub_event+0x1c0/0x4fe0 drivers/usb/core/hub.c:5898
#3: ffff88803c31f198 (&dev->mutex){....}-{4:4}, at: device_lock include/linux/device.h:914 [inline]
#3: ffff88803c31f198 (&dev->mutex){....}-{4:4}, at: __device_attach+0x7e/0x4b0 drivers/base/dd.c:1006
#4: ffff88803b835160 (&dev->mutex){....}-{4:4}, at: device_lock include/linux/device.h:914 [inline]
#4: ffff88803b835160 (&dev->mutex){....}-{4:4}, at: __device_attach+0x7e/0x4b0 drivers/base/dd.c:1006
2 locks held by kworker/u8:9/4728:
1 lock held by syz.6.9313/6232:
#0: ffff88802912d198 (&dev->mutex){....}-{4:4}, at: device_lock include/linux/device.h:914 [inline]
#0: ffff88802912d198 (&dev->mutex){....}-{4:4}, at: usbdev_open+0x1b6/0x8b0 drivers/usb/core/devio.c:1054
1 lock held by syz-executor/6621:
#0: ffffffff8e1cebb8 (rcu_state.exp_mutex){+.+.}-{4:4}, at: exp_funnel_lock+0x284/0x3c0 kernel/rcu/tree_exp.h:311
=============================================
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 08/18/2025
Call Trace:
__dump_stack lib/dump_stack.c:94 [inline]
dump_stack_lvl+0x116/0x1f0 lib/dump_stack.c:120
nmi_cpu_backtrace+0x27b/0x390 lib/nmi_backtrace.c:113
nmi_trigger_cpumask_backtrace+0x29c/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+0xf0e/0x1260 kernel/hung_task.c:491
kthread+0x3c5/0x780 kernel/kthread.c:463
ret_from_fork+0x56a/0x730 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: 18548 Comm: kworker/u8:49 Not tainted syzkaller #0 PREEMPT(full)
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 08/18/2025
Workqueue: events_unbound nsim_dev_trap_report_work
RIP: 0010:__lock_acquire+0x1c1/0x1ce0 kernel/locking/lockdep.c:5174
Code: c0 65 8b 15 99 1c e5 11 85 f6 0f 95 c0 85 d2 0f 95 c2 41 c1 e6 0f c1 e1 10 0f b6 d2 45 0f b7 f6 41 c1 e0 13 8d 04 50 8b 14 24 <81> e1 00 00 03 00 c1 e0 0d 44 09 f0 c1 e2 12 09 c8 81 e2 00 00 04
RSP: 0018:ffffc9000c7274f0 EFLAGS: 00000046
RAX: 0000000000000000 RBX: ffff888027ed5430 RCX: 0000000000020000
RDX: 0000000000000000 RSI: 0000000000000000 RDI: ffff888027ed54d0
RBP: 0000000000000000 R08: 0000000000000000 R09: 0000000000000000
R10: 00000000000000a0 R11: 0000000000000001 R12: ffff888027ed54d0
R13: ffff888027ed4900 R14: 0000000000000000 R15: ffffffff8e1c3620
FS: 0000000000000000(0000) GS:ffff888124e60000(0000) knlGS:0000000000000000
CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 000055555e96e5c8 CR3: 000000002d5cb000 CR4: 00000000003526f0
Call Trace:
lock_acquire kernel/locking/lockdep.c:5868 [inline]
lock_acquire+0x179/0x350 kernel/locking/lockdep.c:5825
rcu_lock_acquire include/linux/rcupdate.h:331 [inline]
rcu_read_lock include/linux/rcupdate.h:841 [inline]
class_rcu_constructor include/linux/rcupdate.h:1169 [inline]
unwind_next_frame+0xd1/0x20a0 arch/x86/kernel/unwind_orc.c:479
arch_stack_walk+0x94/0x100 arch/x86/kernel/stacktrace.c:25
stack_trace_save+0x8e/0xc0 kernel/stacktrace.c:122
kasan_save_stack+0x33/0x60 mm/kasan/common.c:47
kasan_save_track+0x14/0x30 mm/kasan/common.c:68
poison_kmalloc_redzone mm/kasan/common.c:388 [inline]
__kasan_kmalloc+0xaa/0xb0 mm/kasan/common.c:405
kasan_kmalloc include/linux/kasan.h:260 [inline]
__do_kmalloc_node mm/slub.c:4376 [inline]
__kmalloc_node_track_caller_noprof+0x221/0x510 mm/slub.c:4395
kmalloc_reserve+0xef/0x2c0 net/core/skbuff.c:600
__alloc_skb+0x166/0x380 net/core/skbuff.c:669
alloc_skb include/linux/skbuff.h:1336 [inline]
nsim_dev_trap_skb_build drivers/net/netdevsim/dev.c:763 [inline]
nsim_dev_trap_report drivers/net/netdevsim/dev.c:820 [inline]
nsim_dev_trap_report_work+0x2b1/0xcf0 drivers/net/netdevsim/dev.c:866
process_one_work+0x9cf/0x1b70 kernel/workqueue.c:3263
process_scheduled_works kernel/workqueue.c:3346 [inline]
worker_thread+0x6c8/0xf10 kernel/workqueue.c:3427
kthread+0x3c5/0x780 kernel/kthread.c:463
ret_from_fork+0x56a/0x730 arch/x86/kernel/process.c:148
ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:245