INFO: task kworker/0:8:11247 blocked for more than 143 seconds.
Not tainted 6.14.0-rc3-syzkaller-00071-gb331a3d8097f #0
"echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message.
task:kworker/0:8 state:D stack:22808 pid:11247 tgid:11247 ppid:2 task_flags:0x4288060 flags:0x00004000
Workqueue: usb_hub_wq hub_event
Call Trace:
context_switch kernel/sched/core.c:5378 [inline]
__schedule+0x113d/0x35d0 kernel/sched/core.c:6765
__schedule_loop kernel/sched/core.c:6842 [inline]
schedule+0xe7/0x350 kernel/sched/core.c:6857
schedule_preempt_disabled+0x13/0x30 kernel/sched/core.c:6914
__mutex_lock_common kernel/locking/mutex.c:662 [inline]
__mutex_lock+0x6bd/0xb10 kernel/locking/mutex.c:730
rtnl_net_lock include/linux/rtnetlink.h:129 [inline]
unregister_netdev+0x17/0x30 net/core/dev.c:11885
usbnet_disconnect+0x109/0x500 drivers/net/usb/usbnet.c:1637
usb_unbind_interface+0x1da/0x9a0 drivers/usb/core/driver.c:458
device_remove drivers/base/dd.c:569 [inline]
device_remove+0x122/0x170 drivers/base/dd.c:561
__device_release_driver drivers/base/dd.c:1273 [inline]
device_release_driver_internal+0x44a/0x610 drivers/base/dd.c:1296
bus_remove_device+0x22f/0x420 drivers/base/bus.c:579
device_del+0x396/0x9f0 drivers/base/core.c:3854
usb_disable_device+0x368/0x7e0 drivers/usb/core/message.c:1418
usb_disconnect+0x2e1/0x920 drivers/usb/core/hub.c:2316
hub_port_connect drivers/usb/core/hub.c:5371 [inline]
hub_port_connect_change drivers/usb/core/hub.c:5671 [inline]
port_event drivers/usb/core/hub.c:5831 [inline]
hub_event+0x1bed/0x4f40 drivers/usb/core/hub.c:5913
process_one_work+0x9c5/0x1ba0 kernel/workqueue.c:3236
process_scheduled_works kernel/workqueue.c:3317 [inline]
worker_thread+0x6c8/0xf00 kernel/workqueue.c:3398
kthread+0x3af/0x750 kernel/kthread.c:464
ret_from_fork+0x45/0x80 arch/x86/kernel/process.c:148
ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:244
Showing all locks held in the system:
6 locks held by kworker/0:0/8:
#0: ffff8881062cd148
((wq_completion)usb_hub_wq){+.+.}-{0:0}, at: process_one_work+0x1293/0x1ba0 kernel/workqueue.c:3211
#1:
ffffc9000008fd18
((work_completion)(&hub->events)
){+.+.}-{0:0}, at: process_one_work+0x921/0x1ba0 kernel/workqueue.c:3212
#2: ffff88810b39b198 (&dev->mutex
){....}-{4:4}
, at: device_lock include/linux/device.h:1030 [inline]
, at: hub_event+0x1be/0x4f40 drivers/usb/core/hub.c:5859
#3:
ffff888119173198
(&dev->mutex){....}-{4:4}, at: device_lock include/linux/device.h:1030 [inline]
(&dev->mutex){....}-{4:4}, at: __device_attach+0x7f/0x4b0 drivers/base/dd.c:1005
#4: ffff88810c29f160 (&dev->mutex){....}-{4:4}, at: device_lock include/linux/device.h:1030 [inline]
#4: ffff88810c29f160 (&dev->mutex){....}-{4:4}, at: __device_attach+0x7f/0x4b0 drivers/base/dd.c:1005
#5: ffffffff8a1a02a8 (rtnl_mutex
){+.+.}-{4:4}, at: rtnl_net_lock_killable include/linux/rtnetlink.h:144 [inline]
){+.+.}-{4:4}, at: register_netdev+0x18/0x50 net/core/dev.c:10971
1 lock held by khungtaskd/30:
#0: ffffffff88ebe480 (
rcu_read_lock){....}-{1:3}, at: rcu_lock_acquire include/linux/rcupdate.h:337 [inline]
rcu_read_lock){....}-{1:3}, at: rcu_read_lock include/linux/rcupdate.h:849 [inline]
rcu_read_lock){....}-{1:3}, at: debug_show_all_locks+0x7f/0x390 kernel/locking/lockdep.c:6746
3 locks held by kworker/u8:6/1485:
#0: ffff88810f314148 ((wq_completion)ipv6_addrconf
){+.+.}-{0:0}
, at: process_one_work+0x1293/0x1ba0 kernel/workqueue.c:3211
#1: ffffc900027cfd18
((work_completion)(&(&net->ipv6.addr_chk_work)->work)){+.+.}-{0:0}, at: process_one_work+0x921/0x1ba0 kernel/workqueue.c:3212
#2: ffffffff8a1a02a8 (rtnl_mutex){+.+.}-{4:4}
, at: rtnl_net_lock include/linux/rtnetlink.h:129 [inline]
, at: addrconf_verify_work+0x12/0x30 net/ipv6/addrconf.c:4730
1 lock held by dhcpcd/2881:
2 locks held by getty/2903:
#0: ffff888108afc0a0 (
&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+0xfba/0x1480 drivers/tty/n_tty.c:2211
4 locks held by udevd/5224:
#0: ffff8881135cfb08 (&p->lock){+.+.}-{4:4}, at: seq_read_iter+0xd8/0x12b0 fs/seq_file.c:182
#1: ffff888119dc4888 (&of->mutex#2){+.+.}-{4:4}, at: kernfs_seq_start+0x4d/0x240 fs/kernfs/file.c:154
#2: ffff888111572788 (
kn->active#5){++++}-{0:0}, at: kernfs_seq_start+0x71/0x240 fs/kernfs/file.c:155
#3: ffff88811145b160 (&dev->mutex){....}-{4:4}
, at: device_lock include/linux/device.h:1030 [inline]
, at: uevent_show+0x188/0x3b0 drivers/base/core.c:2729
6 locks held by kworker/1:5/5297:
#0: ffff8881062cd148 ((wq_completion)usb_hub_wq){+.+.}-{0:0}, at: process_one_work+0x1293/0x1ba0 kernel/workqueue.c:3211
#1:
ffffc9000229fd18 ((work_completion)(&hub->events)){+.+.}-{0:0}, at: process_one_work+0x921/0x1ba0 kernel/workqueue.c:3212
#2:
ffff88810b77b198 (&dev->mutex){....}-{4:4}, at: device_lock include/linux/device.h:1030 [inline]
ffff88810b77b198 (&dev->mutex){....}-{4:4}, at: hub_event+0x1be/0x4f40 drivers/usb/core/hub.c:5859
#3: ffff888112bc4198 (&dev->mutex){....}-{4:4}, at: device_lock include/linux/device.h:1030 [inline]
#3: ffff888112bc4198 (&dev->mutex){....}-{4:4}, at: __device_attach+0x7f/0x4b0 drivers/base/dd.c:1005
#4:
ffff88811f327160 (&dev->mutex){....}-{4:4}, at: device_lock include/linux/device.h:1030 [inline]
ffff88811f327160 (&dev->mutex){....}-{4:4}, at: __device_attach+0x7f/0x4b0 drivers/base/dd.c:1005
#5:
ffffffff8a1a02a8 (rtnl_mutex){+.+.}-{4:4}, at: rtnl_net_lock_killable include/linux/rtnetlink.h:144 [inline]
ffffffff8a1a02a8 (rtnl_mutex){+.+.}-{4:4}, at: register_netdev+0x18/0x50 net/core/dev.c:10971
4 locks held by udevd/6143:
#0: ffff88811e8cc1c8 (&p->lock){+.+.}-{4:4}, at: seq_read_iter+0xd8/0x12b0 fs/seq_file.c:182
#1: ffff888112dc9488
(&of->mutex#2){+.+.}-{4:4}, at: kernfs_seq_start+0x4d/0x240 fs/kernfs/file.c:154
#2: ffff88810768bd28 (kn->active#5){++++}-{0:0}, at: kernfs_seq_start+0x71/0x240 fs/kernfs/file.c:155
#3: ffff888119173198 (&dev->mutex){....}-{4:4}, at: device_lock include/linux/device.h:1030 [inline]
#3: ffff888119173198 (&dev->mutex){....}-{4:4}, at: uevent_show+0x188/0x3b0 drivers/base/core.c:2729
6 locks held by kworker/1:7/6187:
#0: ffff8881062cd148 ((wq_completion)usb_hub_wq){+.+.}-{0:0}, at: process_one_work+0x1293/0x1ba0 kernel/workqueue.c:3211
#1:
ffffc900144d7d18 ((work_completion)(&hub->events)
){+.+.}-{0:0}, at: process_one_work+0x921/0x1ba0 kernel/workqueue.c:3212
#2:
ffff88810b75b198 (&dev->mutex){....}-{4:4}, at: device_lock include/linux/device.h:1030 [inline]
ffff88810b75b198 (&dev->mutex){....}-{4:4}, at: hub_event+0x1be/0x4f40 drivers/usb/core/hub.c:5859
#3: ffff888134b3a198 (&dev->mutex){....}-{4:4}, at: device_lock include/linux/device.h:1030 [inline]
#3: ffff888134b3a198 (&dev->mutex){....}-{4:4}, at: __device_attach+0x7f/0x4b0 drivers/base/dd.c:1005
#4:
ffff88811145b160 (&dev->mutex){....}-{4:4}, at: device_lock include/linux/device.h:1030 [inline]
ffff88811145b160 (&dev->mutex){....}-{4:4}, at: __device_attach+0x7f/0x4b0 drivers/base/dd.c:1005
#5: ffffffff8a1a02a8 (rtnl_mutex){+.+.}-{4:4}, at: rtnl_net_lock_killable include/linux/rtnetlink.h:144 [inline]
#5: ffffffff8a1a02a8 (rtnl_mutex){+.+.}-{4:4}, at: register_netdev+0x18/0x50 net/core/dev.c:10971
7 locks held by kworker/0:8/11247:
#0: ffff8881062cd148 ((wq_completion)usb_hub_wq){+.+.}-{0:0}, at: process_one_work+0x1293/0x1ba0 kernel/workqueue.c:3211
#1: ffffc900019ffd18
((work_completion)(&hub->events)){+.+.}-{0:0}, at: process_one_work+0x921/0x1ba0 kernel/workqueue.c:3212
#2: ffff88810bb70198 (&dev->mutex){....}-{4:4}, at: device_lock include/linux/device.h:1030 [inline]
#2: ffff88810bb70198 (&dev->mutex){....}-{4:4}, at: hub_event+0x1be/0x4f40 drivers/usb/core/hub.c:5859
#3:
ffff88811c8a6198 (&dev->mutex){....}-{4:4}, at: device_lock include/linux/device.h:1030 [inline]
ffff88811c8a6198 (&dev->mutex){....}-{4:4}, at: usb_disconnect+0x10a/0x920 drivers/usb/core/hub.c:2307
#4: ffff88811a795160 (&dev->mutex){....}-{4:4}, at: device_lock include/linux/device.h:1030 [inline]
#4: ffff88811a795160 (&dev->mutex){....}-{4:4}, at: __device_driver_lock drivers/base/dd.c:1095 [inline]
#4: ffff88811a795160 (&dev->mutex){....}-{4:4}, at: device_release_driver_internal+0xa4/0x610 drivers/base/dd.c:1293
#5:
ffffffff8a1a02a8 (rtnl_mutex){+.+.}-{4:4}
, at: rtnl_net_lock include/linux/rtnetlink.h:129 [inline]
, at: unregister_netdev+0x17/0x30 net/core/dev.c:11885
#6: ffffffff88ec98f8 (rcu_state.exp_mutex){+.+.}-{4:4}, at: exp_funnel_lock+0x282/0x3b0 kernel/rcu/tree_exp.h:302
=============================================
NMI backtrace for cpu 1
CPU: 1 UID: 0 PID: 30 Comm: khungtaskd Not tainted 6.14.0-rc3-syzkaller-00071-gb331a3d8097f #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 02/12/2025
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:162 [inline]
check_hung_uninterruptible_tasks kernel/hung_task.c:236 [inline]
watchdog+0xf62/0x12b0 kernel/hung_task.c:399
kthread+0x3af/0x750 kernel/kthread.c:464
ret_from_fork+0x45/0x80 arch/x86/kernel/process.c:148
ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:244
Sending NMI from CPU 1 to CPUs 0:
NMI backtrace for cpu 0
CPU: 0 UID: 0 PID: 6593 Comm: kworker/0:7 Not tainted 6.14.0-rc3-syzkaller-00071-gb331a3d8097f #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 02/12/2025
Workqueue: events legacy_dvb_usb_read_remote_control
RIP: 0010:io_serial_in+0x87/0xb0 drivers/tty/serial/8250/8250_port.c:410
Code: 55 b2 fe 48 8d 7d 40 44 89 e1 48 b8 00 00 00 00 00 fc ff df 48 89 fa d3 e3 48 c1 ea 03 80 3c 02 00 75 1a 66 03 5d 40 89 da ec <5b> 0f b6 c0 5d 41 5c c3 cc cc cc cc e8 28 69 0c ff eb a2 e8 b1 69
RSP: 0018:ffffc90013b3f678 EFLAGS: 00000002
RAX: dffffc0000000060 RBX: 00000000000003fd RCX: 0000000000000000
RDX: 00000000000003fd RSI: ffffffff82c8e140 RDI: ffffffff9366d2a0
RBP: ffffffff9366d260 R08: 0000000000000001 R09: 000000000000001f
R10: 0000000000000000 R11: 0000000000000006 R12: 0000000000000000
R13: 0000000000000020 R14: fffffbfff26cdaa6 R15: dffffc0000000000
FS: 0000000000000000(0000) GS:ffff8881f5800000(0000) knlGS:0000000000000000
CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 00007fff886d1cd8 CR3: 0000000117838000 CR4: 00000000003506f0
DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400
Call Trace:
serial_in drivers/tty/serial/8250/8250.h:137 [inline]
serial_lsr_in drivers/tty/serial/8250/8250.h:159 [inline]
wait_for_lsr+0x137/0x210 drivers/tty/serial/8250/8250_port.c:2100
fifo_wait_for_lsr drivers/tty/serial/8250/8250_port.c:3357 [inline]
serial8250_console_fifo_write drivers/tty/serial/8250/8250_port.c:3380 [inline]
serial8250_console_write+0xf6c/0x1870 drivers/tty/serial/8250/8250_port.c:3465
console_emit_next_record kernel/printk/printk.c:3122 [inline]
console_flush_all+0x800/0xc60 kernel/printk/printk.c:3210
__console_flush_and_unlock kernel/printk/printk.c:3269 [inline]
console_unlock+0xd9/0x210 kernel/printk/printk.c:3309
vprintk_emit+0x424/0x6f0 kernel/printk/printk.c:2432
_printk+0xc8/0x100 kernel/printk/printk.c:2457
m920x_read drivers/media/usb/dvb-usb/m920x.c:40 [inline]
m920x_rc_query+0x496/0x770 drivers/media/usb/dvb-usb/m920x.c:193
legacy_dvb_usb_read_remote_control+0x10a/0x500 drivers/media/usb/dvb-usb/dvb-usb-remote.c:123
process_one_work+0x9c5/0x1ba0 kernel/workqueue.c:3236
process_scheduled_works kernel/workqueue.c:3317 [inline]
worker_thread+0x6c8/0xf00 kernel/workqueue.c:3398
kthread+0x3af/0x750 kernel/kthread.c:464
ret_from_fork+0x45/0x80 arch/x86/kernel/process.c:148
ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:244