syzbot

INFO: task kworker/0:3:5223 blocked for more than 143 seconds.
      Not tainted 6.15.0-rc4-syzkaller-00104-g588d032e9e56 #0
"echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message.
task:kworker/0:3     state:D
 stack:21192 pid:5223  tgid:5223  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:12063
 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:
1 lock held by khungtaskd/30:
 #0: 
ffffffff890c2880
 (rcu_read_lock){....}-{1:3}
, at: rcu_lock_acquire include/linux/rcupdate.h:331 [inline]
, at: rcu_read_lock include/linux/rcupdate.h:841 [inline]
, at: debug_show_all_locks+0x36/0x1c0 kernel/locking/lockdep.c:6764
3 locks held by kworker/u8:7/1447:
 #0: ffff888111fe3148
 ((wq_completion)ipv6_addrconf
){+.+.}-{0:0}
, at: process_one_work+0x12a2/0x1b70 kernel/workqueue.c:3213
 #1: ffffc9000211fd18 ((work_completion)(&(&net->ipv6.addr_chk_work)->work)){+.+.}-{0:0}
, at: process_one_work+0x929/0x1b70 kernel/workqueue.c:3214
 #2: ffffffff8a3b6fa8
 (rtnl_mutex){+.+.}-{4:4}
, at: rtnl_net_lock include/linux/rtnetlink.h:130 [inline]
, at: addrconf_verify_work+0x12/0x30 net/ipv6/addrconf.c:4735
1 lock held by dhcpcd/2878:
2 locks held by getty/2898:
 #0: ffff88810830f0a0 (
&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/0:3/5223:
 #0: ffff8881066b3148
 ((wq_completion)usb_hub_wq
){+.+.}-{0:0}, at: process_one_work+0x12a2/0x1b70 kernel/workqueue.c:3213
 #1: 
ffffc9000222fd18 ((work_completion)(&hub->events)
){+.+.}-{0:0}, at: process_one_work+0x929/0x1b70 kernel/workqueue.c:3214
 #2: ffff88810afa7198 (&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: ffff88811e244198 (&dev->mutex){....}-{4:4}, at: device_lock include/linux/device.h:922 [inline]
 #3: ffff88811e244198 (&dev->mutex){....}-{4:4}, at: usb_disconnect+0x10a/0x920 drivers/usb/core/hub.c:2307
 #4: ffff888121a51160 (&dev->mutex
){....}-{4:4}
, at: device_lock include/linux/device.h:922 [inline]
, at: __device_driver_lock drivers/base/dd.c:1094 [inline]
, at: device_release_driver_internal+0xa4/0x620 drivers/base/dd.c:1292
 #5: ffffffff8a3b6fa8
 (rtnl_mutex){+.+.}-{4:4}, at: rtnl_net_lock include/linux/rtnetlink.h:130 [inline]
 (rtnl_mutex){+.+.}-{4:4}, at: rtnl_net_dev_lock+0x146/0x360 net/core/dev.c:2089
5 locks held by kworker/1:3/5229:
2 locks held by kworker/0:4/5232:
 #0: ffff888100080d48
 (
(wq_completion)events){+.+.}-{0:0}, at: process_one_work+0x12a2/0x1b70 kernel/workqueue.c:3213
 #1: ffffc90003abfd18 ((work_completion)(&fw_work->work)){+.+.}-{0:0}, at: process_one_work+0x929/0x1b70 kernel/workqueue.c:3214
4 locks held by udevd/5387:
 #0: ffff88811ddf09e0
 (&p->lock){+.+.}-{4:4}, at: seq_read_iter+0xe1/0x12c0 fs/seq_file.c:182
 #1: ffff888112985c88 (&of->mutex#2){+.+.}-{4:4}, at: kernfs_seq_start+0x4d/0x240 fs/kernfs/file.c:154
 #2: ffff8881086fc0f8 (kn->active#18){++++}-{0:0}, at: kernfs_seq_start+0x71/0x240 fs/kernfs/file.c:155
 #3: ffff88811c7ec198 (&dev->mutex){....}-{4:4}, at: device_lock_interruptible include/linux/device.h:927 [inline]
 #3: ffff88811c7ec198 (&dev->mutex){....}-{4:4}, at: manufacturer_show+0x26/0xa0 drivers/usb/core/sysfs.c:142
6 locks held by kworker/1:0/8000:
 #0: ffff8881066b3148 ((wq_completion)usb_hub_wq){+.+.}-{0:0}, at: process_one_work+0x12a2/0x1b70 kernel/workqueue.c:3213
 #1: 
ffffc90001d1fd18 ((work_completion)(&hub->events)){+.+.}-{0:0}, at: process_one_work+0x929/0x1b70 kernel/workqueue.c:3214
 #2: ffff88810af0f198 (&dev->mutex){....}-{4:4}, at: device_lock include/linux/device.h:922 [inline]
 #2: ffff88810af0f198 (&dev->mutex){....}-{4:4}, at: hub_event+0x1be/0x5030 drivers/usb/core/hub.c:5863
 #3: ffff88811c7ec198 (&dev->mutex){....}-{4:4}
, at: device_lock include/linux/device.h:922 [inline]
, at: __device_attach+0x7e/0x4b0 drivers/base/dd.c:1004
 #4: ffff8881188fb160 (&dev->mutex){....}-{4:4}
, at: device_lock include/linux/device.h:922 [inline]
, at: __device_attach+0x7e/0x4b0 drivers/base/dd.c:1004
 #5: ffffffff8a3b6fa8 (rtnl_mutex){+.+.}-{4:4}, at: ieee80211_register_hw+0x20aa/0x4090 net/mac80211/main.c:1530
2 locks held by kworker/0:8/10958:
1 lock held by syz.4.1826/11378:

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

NMI backtrace for cpu 1
CPU: 1 UID: 0 PID: 30 Comm: khungtaskd Not tainted 6.15.0-rc4-syzkaller-00104-g588d032e9e56 #0 PREEMPT(voluntary) 
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 04/19/2025
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: 10 Comm: kworker/0:1 Not tainted 6.15.0-rc4-syzkaller-00104-g588d032e9e56 #0 PREEMPT(voluntary) 
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 04/19/2025
Workqueue: events legacy_dvb_usb_read_remote_control
RIP: 0010:find_endpoint+0x193/0x2c0 drivers/usb/gadget/udc/dummy_hcd.c:1587
Code: fc ff df 89 de 41 89 dd bb 01 00 00 00 e8 e5 37 95 fc 45 85 ed 75 2f e8 9b 3c 95 fc 49 83 c4 40 e9 ab 00 00 00 e8 8d 3c 95 fc <83> c3 01 bf 19 00 00 00 48 83 c5 78 89 de e8 ba 37 95 fc 83 fb 19
RSP: 0018:ffffc90000007ba8 EFLAGS: 00000046
RAX: 0000000000000000 RBX: 0000000000000003 RCX: ffffffff84e72ee6
RDX: ffff8881016a1d40 RSI: ffffffff84e72ed3 RDI: 0000000000000005
RBP: ffff88810af1c1c8 R08: 0000000000000005 R09: 0000000000000019
R10: 0000000000000003 R11: ffff88810b309470 R12: ffff88810af1c000
R13: 0000000000000003 R14: dffffc0000000000 R15: 0000000000000000
FS:  0000000000000000(0000) GS:ffff8882691c4000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 00007f33bd704ff0 CR3: 0000000130ed0000 CR4: 00000000003506f0
DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400
Call Trace:
 <IRQ>
 dummy_timer+0x4dd/0x3a20 drivers/usb/gadget/udc/dummy_hcd.c:1863
 __run_hrtimer kernel/time/hrtimer.c:1761 [inline]
 __hrtimer_run_queues+0x1ff/0xad0 kernel/time/hrtimer.c:1825
 hrtimer_run_softirq+0x17d/0x350 kernel/time/hrtimer.c:1842
 handle_softirqs+0x205/0x8d0 kernel/softirq.c:579
 __do_softirq kernel/softirq.c:613 [inline]
 invoke_softirq kernel/softirq.c:453 [inline]
 __irq_exit_rcu+0xfa/0x160 kernel/softirq.c:680
 irq_exit_rcu+0x9/0x30 kernel/softirq.c:696
 instr_sysvec_apic_timer_interrupt arch/x86/kernel/apic/apic.c:1049 [inline]
 sysvec_apic_timer_interrupt+0x90/0xb0 arch/x86/kernel/apic/apic.c:1049
 </IRQ>
 <TASK>
 asm_sysvec_apic_timer_interrupt+0x1a/0x20 arch/x86/include/asm/idtentry.h:702
RIP: 0010:console_trylock_spinning kernel/printk/printk.c:2061 [inline]
RIP: 0010:vprintk_emit+0x567/0x6d0 kernel/printk/printk.c:2449
Code: 00 4d 85 ed 0f 85 19 01 00 00 e8 94 df 1f 00 9c 5d 81 e5 00 02 00 00 31 ff 48 89 ee e8 f2 da 1f 00 48 85 ed 0f 85 25 01 00 00 <e8> 74 df 1f 00 45 31 c9 41 b8 01 00 00 00 31 c9 48 8d 05 00 00 00
RSP: 0018:ffffc900000af9f0 EFLAGS: 00000293
RAX: 0000000000000000 RBX: 0000000000000017 RCX: ffffffff815c8cfc
RDX: ffff8881016a1d40 RSI: ffffffff815c8d06 RDI: 0000000000000007
RBP: 0000000000000000 R08: 0000000000000007 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000000 R12: 1ffff92000015f40
R13: 0000000000000200 R14: ffff888101edd7c0 R15: ffffc900000afab8
 _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>