INFO: task kworker/1:4:19343 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:21800 pid:19343 tgid:19343 ppid:2 task_flags:0x4288060 flags:0x00004000
Workqueue: usb_hub_wq hub_event
Call Trace:
context_switch kernel/sched/core.c:5357 [inline]
__schedule+0x12fc/0x3b90 kernel/sched/core.c:6961
__schedule_loop kernel/sched/core.c:7043 [inline]
schedule+0xe7/0x3a0 kernel/sched/core.c:7058
schedule_preempt_disabled+0x13/0x30 kernel/sched/core.c:7115
__mutex_lock_common kernel/locking/mutex.c:676 [inline]
__mutex_lock+0x81b/0x1060 kernel/locking/mutex.c:760
rtnl_net_lock include/linux/rtnetlink.h:130 [inline]
rtnl_net_dev_lock+0x146/0x360 net/core/dev.c:2142
unregister_netdev+0x15/0x60 net/core/dev.c:12246
usbnet_disconnect+0x109/0x500 drivers/net/usb/usbnet.c:1658
usb_unbind_interface+0x1da/0x9e0 drivers/usb/core/driver.c:458
device_remove drivers/base/dd.c:571 [inline]
device_remove+0x122/0x170 drivers/base/dd.c:563
__device_release_driver drivers/base/dd.c:1274 [inline]
device_release_driver_internal+0x44b/0x620 drivers/base/dd.c:1297
bus_remove_device+0x22f/0x420 drivers/base/bus.c:579
device_del+0x396/0x9f0 drivers/base/core.c:3878
usb_disable_device+0x355/0x7d0 drivers/usb/core/message.c:1418
usb_disconnect+0x2e1/0x9c0 drivers/usb/core/hub.c:2344
hub_port_connect drivers/usb/core/hub.c:5406 [inline]
hub_port_connect_change drivers/usb/core/hub.c:5706 [inline]
port_event drivers/usb/core/hub.c:5870 [inline]
hub_event+0x1aa2/0x5060 drivers/usb/core/hub.c:5952
process_one_work+0x9cf/0x1b70 kernel/workqueue.c:3236
process_scheduled_works kernel/workqueue.c:3319 [inline]
worker_thread+0x6c8/0xf10 kernel/workqueue.c:3400
kthread+0x3c5/0x780 kernel/kthread.c:463
ret_from_fork+0x56d/0x700 arch/x86/kernel/process.c:148
ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:245
Showing all locks held in the system:
1 lock held by khungtaskd/30:
#0: ffffffff892c76e0 (rcu_read_lock){....}-{1:3}, at: rcu_lock_acquire include/linux/rcupdate.h:331 [inline]
#0: ffffffff892c76e0 (rcu_read_lock){....}-{1:3}, at: rcu_read_lock include/linux/rcupdate.h:841 [inline]
#0: ffffffff892c76e0 (rcu_read_lock){....}-{1:3}, at: debug_show_all_locks+0x36/0x1c0 kernel/locking/lockdep.c:6775
3 locks held by dhcpcd/2888:
2 locks held by getty/2913:
#0: ffff888109ec50a0 (&tty->ldisc_sem){++++}-{0:0}, at: tty_ldisc_ref_wait+0x24/0x80 drivers/tty/tty_ldisc.c:243
#1: ffffc900000432f0 (&ldata->atomic_read_lock){+.+.}-{4:4}, at: n_tty_read+0x41b/0x14f0 drivers/tty/n_tty.c:2222
4 locks held by udevd/5198:
#0: ffff8881184b52f0 (&p->lock){+.+.}-{4:4}, at: seq_read_iter+0xe1/0x12c0 fs/seq_file.c:182
#1: ffff8881073ebc88 (&of->mutex#2){+.+.}-{4:4}, at: kernfs_seq_start+0x4f/0x2a0 fs/kernfs/file.c:172
#2: ffff88812c774c38 (kn->active#9){++++}-{0:0}, at: kernfs_get_active_of fs/kernfs/file.c:80 [inline]
#2: ffff88812c774c38 (kn->active#9){++++}-{0:0}, at: kernfs_seq_start+0xbc/0x2a0 fs/kernfs/file.c:173
#3: ffff888138ba0198 (&dev->mutex){....}-{4:4}, at: device_lock_interruptible include/linux/device.h:916 [inline]
#3: ffff888138ba0198 (&dev->mutex){....}-{4:4}, at: manufacturer_show+0x26/0xa0 drivers/usb/core/sysfs.c:142
4 locks held by udevd/5204:
#0: ffff88814ab46b08 (&p->lock){+.+.}-{4:4}, at: seq_read_iter+0xe1/0x12c0 fs/seq_file.c:182
#1: ffff88811895fc88 (&of->mutex#2){+.+.}-{4:4}, at: kernfs_seq_start+0x4f/0x2a0 fs/kernfs/file.c:172
#2: ffff888112e0b4b8 (kn->active#9){++++}-{0:0}, at: kernfs_get_active_of fs/kernfs/file.c:80 [inline]
#2: ffff888112e0b4b8 (kn->active#9){++++}-{0:0}, at: kernfs_seq_start+0xbc/0x2a0 fs/kernfs/file.c:173
#3: ffff888116a74198 (&dev->mutex){....}-{4:4}, at: device_lock_interruptible include/linux/device.h:916 [inline]
#3: ffff888116a74198 (&dev->mutex){....}-{4:4}, at: manufacturer_show+0x26/0xa0 drivers/usb/core/sysfs.c:142
6 locks held by kworker/1:0/13576:
#0: ffff888106ece548 ((wq_completion)usb_hub_wq){+.+.}-{0:0}, at: process_one_work+0x12a2/0x1b70 kernel/workqueue.c:3211
#1: ffffc9001467fd10 ((work_completion)(&hub->events)){+.+.}-{0:0}, at: process_one_work+0x929/0x1b70 kernel/workqueue.c:3212
#2: ffff88810b398198 (&dev->mutex){....}-{4:4}, at: device_lock include/linux/device.h:911 [inline]
#2: ffff88810b398198 (&dev->mutex){....}-{4:4}, at: hub_event+0x1be/0x5060 drivers/usb/core/hub.c:5898
#3: ffff88812c8bb198
(&dev->mutex){....}-{4:4}, at: device_lock include/linux/device.h:911 [inline]
(&dev->mutex){....}-{4:4}, at: __device_attach+0x7e/0x4b0 drivers/base/dd.c:1006
#4: ffff8881443a3160 (&dev->mutex){....}-{4:4}, at: device_lock include/linux/device.h:911 [inline]
#4: ffff8881443a3160 (&dev->mutex){....}-{4:4}, at: __device_attach+0x7e/0x4b0 drivers/base/dd.c:1006
#5: ffffffff8a5fc208 (rtnl_mutex){+.+.}-{4:4}, at: rtnl_net_lock_killable include/linux/rtnetlink.h:145 [inline]
#5: ffffffff8a5fc208 (rtnl_mutex){+.+.}-{4:4}, at: register_netdev+0x18/0x50 net/core/dev.c:11319
6 locks held by kworker/1:4/19343:
#0: ffff888106ece548 ((wq_completion)usb_hub_wq){+.+.}-{0:0}, at: process_one_work+0x12a2/0x1b70 kernel/workqueue.c:3211
#1: ffffc900018dfd10 ((work_completion)(&hub->events)){+.+.}-{0:0}, at: process_one_work+0x929/0x1b70 kernel/workqueue.c:3212
#2: ffff88810b3fb198 (&dev->mutex){....}-{4:4}, at: device_lock include/linux/device.h:911 [inline]
#2: ffff88810b3fb198 (&dev->mutex){....}-{4:4}, at: hub_event+0x1be/0x5060 drivers/usb/core/hub.c:5898
#3:
ffff888122e02198 (
&dev->mutex){....}-{4:4}
, at: device_lock include/linux/device.h:911 [inline]
, at: usb_disconnect+0x10a/0x9c0 drivers/usb/core/hub.c:2335
#4: ffff88811d971160
(&dev->mutex){....}-{4:4}, at: device_lock include/linux/device.h:911 [inline]
(&dev->mutex){....}-{4:4}, at: __device_driver_lock drivers/base/dd.c:1096 [inline]
(&dev->mutex){....}-{4:4}, at: device_release_driver_internal+0xa4/0x620 drivers/base/dd.c:1294
#5:
ffffffff8a5fc208
(rtnl_mutex){+.+.}-{4:4}
, at: rtnl_net_lock include/linux/rtnetlink.h:130 [inline]
, at: rtnl_net_dev_lock+0x146/0x360 net/core/dev.c:2142
6 locks held by kworker/1:3/24636:
#0:
ffff888106ece548 ((wq_completion)usb_hub_wq
){+.+.}-{0:0}, at: process_one_work+0x12a2/0x1b70 kernel/workqueue.c:3211
#1: ffffc90014f1fd10 ((work_completion)(&hub->events)){+.+.}-{0:0}, at: process_one_work+0x929/0x1b70 kernel/workqueue.c:3212
#2:
ffff88810bb65198
(&dev->mutex){....}-{4:4}, at: device_lock include/linux/device.h:911 [inline]
(&dev->mutex){....}-{4:4}, at: hub_event+0x1be/0x5060 drivers/usb/core/hub.c:5898
#3: ffff888138ba0198
(
&dev->mutex){....}-{4:4}
, at: device_lock include/linux/device.h:911 [inline]
, at: __device_attach+0x7e/0x4b0 drivers/base/dd.c:1006
#4: ffff888114da4160
(&dev->mutex
){....}-{4:4}, at: device_lock include/linux/device.h:911 [inline]
){....}-{4:4}, at: __device_attach+0x7e/0x4b0 drivers/base/dd.c:1006
#5: ffffffff8a5fc208
(rtnl_mutex){+.+.}-{4:4}, at: rtnl_net_lock_killable include/linux/rtnetlink.h:145 [inline]
(rtnl_mutex){+.+.}-{4:4}, at: register_netdev+0x18/0x50 net/core/dev.c:11319
3 locks held by kworker/u8:3/27610:
#0: ffff888111f1e948 ((wq_completion)ipv6_addrconf
){+.+.}-{0:0}
, at: process_one_work+0x12a2/0x1b70 kernel/workqueue.c:3211
#1:
ffffc90012647d10 ((work_completion)(&(&net->ipv6.addr_chk_work)->work)
){+.+.}-{0:0}, at: process_one_work+0x929/0x1b70 kernel/workqueue.c:3212
#2:
ffffffff8a5fc208 (rtnl_mutex){+.+.}-{4:4}
, at: rtnl_net_lock include/linux/rtnetlink.h:130 [inline]
, at: addrconf_verify_work+0x12/0x30 net/ipv6/addrconf.c:4734
6 locks held by kworker/0:9/1294:
#0: ffff888106ece548 ((wq_completion)usb_hub_wq
){+.+.}-{0:0}
, at: process_one_work+0x12a2/0x1b70 kernel/workqueue.c:3211
#1: ffffc90007d27d10 (
(work_completion)(&hub->events)
){+.+.}-{0:0}, at: process_one_work+0x929/0x1b70 kernel/workqueue.c:3212
#2: ffff88810b3e3198 (&dev->mutex){....}-{4:4}
, at: device_lock include/linux/device.h:911 [inline]
, at: hub_event+0x1be/0x5060 drivers/usb/core/hub.c:5898
#3: ffff888116a74198 (&dev->mutex){....}-{4:4}
, at: device_lock include/linux/device.h:911 [inline]
, at: __device_attach+0x7e/0x4b0 drivers/base/dd.c:1006
#4: ffff888130a4d160 (
&dev->mutex){....}-{4:4}
, at: device_lock include/linux/device.h:911 [inline]
, at: __device_attach+0x7e/0x4b0 drivers/base/dd.c:1006
#5: ffffffff8a5fc208 (rtnl_mutex
){+.+.}-{4:4}, at: rtnl_net_lock_killable include/linux/rtnetlink.h:145 [inline]
){+.+.}-{4:4}, at: register_netdev+0x18/0x50 net/core/dev.c:11319
=============================================
NMI backtrace for cpu 1
CPU: 1 UID: 0 PID: 30 Comm: khungtaskd Not tainted syzkaller #0 PREEMPT(voluntary)
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+0x56d/0x700 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: 5236 Comm: kworker/0:4 Not tainted syzkaller #0 PREEMPT(voluntary)
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 08/18/2025
Workqueue: events legacy_dvb_usb_read_remote_control
RIP: 0010:__asan_memcpy+0x6/0x60 mm/kasan/shadow.c:104
Code: 5c e9 9e 07 62 05 5b 31 c0 5d 41 5c c3 cc cc cc cc 0f 1f 00 90 90 90 90 90 90 90 90 90 90 90 90 90 90 90 90 f3 0f 1e fa 41 54 <49> 89 fc 55 48 89 f5 53 48 89 d3 48 8b 4c 24 18 31 d2 48 89 de 48
RSP: 0018:ffffc90003c0f3f0 EFLAGS: 00000293
RAX: 0000000000000000 RBX: ffffffff892b1d18 RCX: ffffffff815e1072
RDX: 0000000000000010 RSI: ffffffff892b1d20 RDI: ffffc90003c0f5b8
RBP: 8000000100049df1 R08: 0000000000000005 R09: 0000000000000000
R10: 0000000000000002 R11: 7373656363612049 R12: 0000000100049df1
R13: ffffc90003c0f5b0 R14: 0000000000000000 R15: ffffc90003c0f468
FS: 0000000000000000(0000) GS:ffff888268ef4000(0000) knlGS:0000000000000000
CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 00007fd4cda75d58 CR3: 000000012724e000 CR4: 00000000003506f0
Call Trace:
desc_read+0x179/0x370 kernel/printk/printk_ringbuffer.c:482
desc_read_finalized_seq+0x89/0x1d0 kernel/printk/printk_ringbuffer.c:1874
prb_read kernel/printk/printk_ringbuffer.c:1942 [inline]
_prb_read_valid+0x4a6/0x890 kernel/printk/printk_ringbuffer.c:2113
prb_read_valid+0x78/0xa0 kernel/printk/printk_ringbuffer.c:2185
printk_get_next_message+0x15b/0x6d0 kernel/printk/printk.c:3005
console_emit_next_record kernel/printk/printk.c:3092 [inline]
console_flush_all+0x6ea/0xc60 kernel/printk/printk.c:3226
__console_flush_and_unlock kernel/printk/printk.c:3285 [inline]
console_unlock+0xd8/0x210 kernel/printk/printk.c:3325
vprintk_emit+0x418/0x6d0 kernel/printk/printk.c:2450
_printk+0xc7/0x100 kernel/printk/printk.c:2475
legacy_dvb_usb_read_remote_control+0x40b/0x4f0 drivers/media/usb/dvb-usb/dvb-usb-remote.c:124
process_one_work+0x9cf/0x1b70 kernel/workqueue.c:3236
process_scheduled_works kernel/workqueue.c:3319 [inline]
worker_thread+0x6c8/0xf10 kernel/workqueue.c:3400
kthread+0x3c5/0x780 kernel/kthread.c:463
ret_from_fork+0x56d/0x700 arch/x86/kernel/process.c:148
ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:245