syzbot

INFO: task kworker/0:8:24194 blocked for more than 143 seconds.
      Not tainted 6.15.0-rc6-syzkaller-00177-g882826f58b2c #0
"echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message.
task:kworker/0:8     state:D stack:22856 pid:24194 tgid:24194 ppid:2      task_flags:0x4288060 flags:0x00004000
Workqueue: usb_hub_wq hub_event

Call Trace:
 <TASK>
 context_switch kernel/sched/core.c:5382 [inline]
 __schedule+0x132a/0x3b00 kernel/sched/core.c:6767
 __schedule_loop kernel/sched/core.c:6845 [inline]
 schedule+0xe7/0x3a0 kernel/sched/core.c:6860
 schedule_preempt_disabled+0x13/0x30 kernel/sched/core.c:6917
 __mutex_lock_common kernel/locking/mutex.c:678 [inline]
 __mutex_lock+0x6c7/0xb90 kernel/locking/mutex.c:746
 rtnl_net_lock include/linux/rtnetlink.h:130 [inline]
 rtnl_net_dev_lock+0x146/0x360 net/core/dev.c:2089
 unregister_netdev+0x15/0x60 net/core/dev.c:12051
 usbnet_disconnect+0x109/0x500 drivers/net/usb/usbnet.c:1648
 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:1272 [inline]
 device_release_driver_internal+0x44b/0x620 drivers/base/dd.c:1295
 bus_remove_device+0x22f/0x420 drivers/base/bus.c:579
 device_del+0x396/0x9f0 drivers/base/core.c:3881
 usb_disable_device+0x355/0x7d0 drivers/usb/core/message.c:1418
 usb_disconnect+0x2e1/0x920 drivers/usb/core/hub.c:2316
 hub_port_connect drivers/usb/core/hub.c:5375 [inline]
 hub_port_connect_change drivers/usb/core/hub.c:5675 [inline]
 port_event drivers/usb/core/hub.c:5835 [inline]
 hub_event+0x1aa0/0x5030 drivers/usb/core/hub.c:5917
 process_one_work+0x9cc/0x1b70 kernel/workqueue.c:3238
 process_scheduled_works kernel/workqueue.c:3319 [inline]
 worker_thread+0x6c8/0xf10 kernel/workqueue.c:3400
 kthread+0x3c2/0x780 kernel/kthread.c:464
 ret_from_fork+0x45/0x80 arch/x86/kernel/process.c:153
 ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:245
 </TASK>

Showing all locks held in the system:
5 locks held by kworker/1:0/23:
 #0: ffff8881066b7d48 ((wq_completion)usb_hub_wq){+.+.}-{0:0}, at: process_one_work+0x12a2/0x1b70 kernel/workqueue.c:3213
 #1: ffffc9000018fd18 ((work_completion)(&hub->events)){+.+.}-{0:0}, at: process_one_work+0x929/0x1b70 kernel/workqueue.c:3214
 #2: ffff88810affb198 (&dev->mutex){....}-{4:4}, at: device_lock include/linux/device.h:922 [inline]
 #2: ffff88810affb198 (&dev->mutex){....}-{4:4}, at: hub_event+0x1be/0x5030 drivers/usb/core/hub.c:5863
 #3: 
ffff888114626198
 (
&dev->mutex
){....}-{4:4}, at: device_lock include/linux/device.h:922 [inline]
){....}-{4:4}, at: __device_attach+0x7e/0x4b0 drivers/base/dd.c:1004
 #4: ffff888109b41d68 (
hcd->bandwidth_mutex
){+.+.}-{4:4}, at: usb_set_configuration+0x616/0x1e20 drivers/usb/core/message.c:2077
1 lock held by khungtaskd/30:
 #0: ffffffff890c2840 (rcu_read_lock){....}-{1:3}, at: rcu_lock_acquire include/linux/rcupdate.h:331 [inline]
 #0: ffffffff890c2840 (rcu_read_lock){....}-{1:3}, at: rcu_read_lock include/linux/rcupdate.h:841 [inline]
 #0: ffffffff890c2840 (rcu_read_lock){....}-{1:3}, at: debug_show_all_locks+0x36/0x1c0 kernel/locking/lockdep.c:6764
1 lock held by dhcpcd/2879:
2 locks held by getty/2902:
 #0: ffff888100ec50a0 (&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
6 locks held by kworker/0:3/5231:
 #0: 
ffff8881066b7d48 ((wq_completion)usb_hub_wq
){+.+.}-{0:0}
, at: process_one_work+0x12a2/0x1b70 kernel/workqueue.c:3213
 #1: 
ffffc90002ddfd18 ((work_completion)(&hub->events)){+.+.}-{0:0}, at: process_one_work+0x929/0x1b70 kernel/workqueue.c:3214
 #2: ffff88810b7d4198 (&dev->mutex
){....}-{4:4}
, at: device_lock include/linux/device.h:922 [inline]
, at: hub_event+0x1be/0x5030 drivers/usb/core/hub.c:5863
 #3: ffff88812e4fc198 (
&dev->mutex){....}-{4:4}, at: device_lock include/linux/device.h:922 [inline]
&dev->mutex){....}-{4:4}, at: __device_attach+0x7e/0x4b0 drivers/base/dd.c:1004
 #4: ffff888136fe6160 (&dev->mutex){....}-{4:4}
, at: device_lock include/linux/device.h:922 [inline]
, at: __device_attach+0x7e/0x4b0 drivers/base/dd.c:1004
 #5: ffffffff8a3b7be8 (rtnl_mutex){+.+.}-{4:4}, at: wpan_phy_register+0x27/0x160 net/ieee802154/core.c:145
4 locks held by udevd/5254:
 #0: ffff88810774cb08 (&p->lock
){+.+.}-{4:4}, at: seq_read_iter+0xe1/0x12c0 fs/seq_file.c:182
 #1: ffff888142088088 (&of->mutex){+.+.}-{4:4}
, at: kernfs_seq_start+0x4d/0x240 fs/kernfs/file.c:154
 #2: 
ffff88811217f788 (kn->active
#18){++++}-{0:0}, at: kernfs_seq_start+0x71/0x240 fs/kernfs/file.c:155
 #3: ffff88812e4fc198
 (&dev->mutex
){....}-{4:4}, at: device_lock_interruptible include/linux/device.h:927 [inline]
){....}-{4:4}, at: manufacturer_show+0x26/0xa0 drivers/usb/core/sysfs.c:142
3 locks held by kworker/u8:0/8004:
 #0: ffff8881121e5148 ((wq_completion)ipv6_addrconf){+.+.}-{0:0}, at: process_one_work+0x12a2/0x1b70 kernel/workqueue.c:3213
 #1: 
ffffc90002e9fd18
 ((work_completion)(&(&net->ipv6.addr_chk_work)->work)){+.+.}-{0:0}, at: process_one_work+0x929/0x1b70 kernel/workqueue.c:3214
 #2: ffffffff8a3b7be8
 (rtnl_mutex
){+.+.}-{4:4}
, at: rtnl_net_lock include/linux/rtnetlink.h:130 [inline]
, at: addrconf_verify_work+0x12/0x30 net/ipv6/addrconf.c:4738
4 locks held by udevd/10202:
 #0: ffff888141cad668 (
&p->lock){+.+.}-{4:4}, at: seq_read_iter+0xe1/0x12c0 fs/seq_file.c:182
 #1: 
ffff88810b398c88 (
&of->mutex){+.+.}-{4:4}, at: kernfs_seq_start+0x4d/0x240 fs/kernfs/file.c:154
 #2: ffff888130987e18 (kn->active#18){++++}-{0:0}
, at: kernfs_seq_start+0x71/0x240 fs/kernfs/file.c:155
 #3: 
ffff888138385198 (&dev->mutex){....}-{4:4}, at: device_lock_interruptible include/linux/device.h:927 [inline]
ffff888138385198 (&dev->mutex){....}-{4:4}, at: manufacturer_show+0x26/0xa0 drivers/usb/core/sysfs.c:142
4 locks held by kworker/0:6/12883:
6 locks held by kworker/1:4/19494:
 #0: 
ffff8881066b7d48 ((wq_completion)usb_hub_wq
){+.+.}-{0:0}
, at: process_one_work+0x12a2/0x1b70 kernel/workqueue.c:3213
 #1: ffffc90001dcfd18 ((work_completion)(&hub->events)){+.+.}-{0:0}, at: process_one_work+0x929/0x1b70 kernel/workqueue.c:3214
 #2: ffff88810b7bc198 (
&dev->mutex){....}-{4:4}, at: device_lock include/linux/device.h:922 [inline]
&dev->mutex){....}-{4:4}, at: hub_event+0x1be/0x5030 drivers/usb/core/hub.c:5863
 #3: ffff888138385198 (
&dev->mutex){....}-{4:4}, at: device_lock include/linux/device.h:922 [inline]
&dev->mutex){....}-{4:4}, at: __device_attach+0x7e/0x4b0 drivers/base/dd.c:1004
 #4: 
ffff88810cb2f160 (&dev->mutex){....}-{4:4}
, at: device_lock include/linux/device.h:922 [inline]
, at: __device_attach+0x7e/0x4b0 drivers/base/dd.c:1004
 #5: ffffffff8a3b7be8 (rtnl_mutex){+.+.}-{4:4}
, at: rtnl_net_lock_killable include/linux/rtnetlink.h:145 [inline]
, at: register_netdev+0x18/0x50 net/core/dev.c:11111
3 locks held by kworker/0:0/22741:
 #0: ffff8881066b7d48 ((wq_completion)usb_hub_wq){+.+.}-{0:0}
, at: process_one_work+0x12a2/0x1b70 kernel/workqueue.c:3213
 #1: ffffc90001d07d18 ((work_completion)(&hub->events)){+.+.}-{0:0}
, at: process_one_work+0x929/0x1b70 kernel/workqueue.c:3214
 #2: 
ffff88810b75c198 (&dev->mutex){....}-{4:4}
, at: device_lock include/linux/device.h:922 [inline]
, at: hub_event+0x1be/0x5030 drivers/usb/core/hub.c:5863
6 locks held by kworker/0:8/24194:
 #0: ffff8881066b7d48
 ((wq_completion)usb_hub_wq){+.+.}-{0:0}, at: process_one_work+0x12a2/0x1b70 kernel/workqueue.c:3213
 #1: ffffc90002b2fd18 ((work_completion)(&hub->events)){+.+.}-{0:0}
, at: process_one_work+0x929/0x1b70 kernel/workqueue.c:3214
 #2: 
ffff88810b774198 (&dev->mutex){....}-{4:4}
, at: device_lock include/linux/device.h:922 [inline]
, at: hub_event+0x1be/0x5030 drivers/usb/core/hub.c:5863
 #3: ffff88812a445198
 (&dev->mutex){....}-{4:4}
, at: device_lock include/linux/device.h:922 [inline]
, at: usb_disconnect+0x10a/0x920 drivers/usb/core/hub.c:2307
 #4: ffff88810137c160 (&dev->mutex){....}-{4:4}, at: device_lock include/linux/device.h:922 [inline]
 #4: ffff88810137c160 (&dev->mutex){....}-{4:4}, at: __device_driver_lock drivers/base/dd.c:1094 [inline]
 #4: ffff88810137c160 (&dev->mutex){....}-{4:4}, at: device_release_driver_internal+0xa4/0x620 drivers/base/dd.c:1292
 #5: 
ffffffff8a3b7be8
 (rtnl_mutex
){+.+.}-{4:4}, at: rtnl_net_lock include/linux/rtnetlink.h:130 [inline]
){+.+.}-{4:4}, at: rtnl_net_dev_lock+0x146/0x360 net/core/dev.c:2089
3 locks held by kworker/0:9/24259:
 #0: 
ffff888100081d48 ((wq_completion)events_power_efficient){+.+.}-{0:0}
, at: process_one_work+0x12a2/0x1b70 kernel/workqueue.c:3213
 #1: ffffc90002d1fd18 (
(reg_check_chans).work
){+.+.}-{0:0}
, at: process_one_work+0x929/0x1b70 kernel/workqueue.c:3214
 #2: ffffffff8a3b7be8 (
rtnl_mutex
){+.+.}-{4:4}, at: reg_check_chans_work+0x83/0x1170 net/wireless/reg.c:2483

=============================================

NMI backtrace for cpu 1
CPU: 1 UID: 0 PID: 30 Comm: khungtaskd Not tainted 6.15.0-rc6-syzkaller-00177-g882826f58b2c #0 PREEMPT(voluntary) 
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 05/07/2025
Call Trace:
 <TASK>
 __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:158 [inline]
 check_hung_uninterruptible_tasks kernel/hung_task.c:274 [inline]
 watchdog+0xf70/0x12c0 kernel/hung_task.c:437
 kthread+0x3c2/0x780 kernel/kthread.c:464
 ret_from_fork+0x45/0x80 arch/x86/kernel/process.c:153
 ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:245
 </TASK>
Sending NMI from CPU 1 to CPUs 0:
NMI backtrace for cpu 0
CPU: 0 UID: 0 PID: 22741 Comm: kworker/0:0 Not tainted 6.15.0-rc6-syzkaller-00177-g882826f58b2c #0 PREEMPT(voluntary) 
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 05/07/2025
Workqueue: events legacy_dvb_usb_read_remote_control
RIP: 0010:get_data+0x3a9/0x540 kernel/printk/printk_ringbuffer.c:1237
Code: 89 1e eb 0b e8 18 3e 1f 00 90 0f 0b 90 31 ed e8 0d 3e 1f 00 48 89 e8 48 83 c4 18 5b 5d 41 5c 41 5d 41 5e 41 5f c3 cc cc cc cc <e8> f2 3d 1f 00 48 8b 34 24 48 89 ef e8 96 38 1f 00 48 8b 04 24 48
RSP: 0018:ffffc90001d07448 EFLAGS: 00000246
RAX: 000000000000002b RBX: ffffc90001d07570 RCX: 000000000000002b
RDX: ffff88811b113a80 RSI: 000000000000002b RDI: 0000000000000006
RBP: 0000000000ae1600 R08: 0000000000000006 R09: 000000000000002b
R10: 000000000000002b R11: 0000000000000000 R12: 0000000000000012
R13: ffffffff88fcfd90 R14: ffffc90001d07538 R15: ffffc90001d07578
FS:  0000000000000000(0000) GS:ffff8882691c2000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 00007ffe11f2ffe8 CR3: 0000000116f90000 CR4: 00000000003506f0
DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400
Call Trace:
 <TASK>
 copy_data kernel/printk/printk_ringbuffer.c:1827 [inline]
 prb_read kernel/printk/printk_ringbuffer.c:1936 [inline]
 _prb_read_valid+0x347/0x890 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
 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+0x109/0x4f0 drivers/media/usb/dvb-usb/dvb-usb-remote.c:123
 process_one_work+0x9cc/0x1b70 kernel/workqueue.c:3238
 process_scheduled_works kernel/workqueue.c:3319 [inline]
 worker_thread+0x6c8/0xf10 kernel/workqueue.c:3400
 kthread+0x3c2/0x780 kernel/kthread.c:464
 ret_from_fork+0x45/0x80 arch/x86/kernel/process.c:153
 ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:245
 </TASK>