syzbot

INFO: task kworker/1:7:6211 blocked for more than 143 seconds.
      Not tainted syzkaller #0
"echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message.
task:kworker/1:7     state:D
 stack:21200 pid:6211  tgid:6211  ppid:2      task_flags:0x4288060 flags:0x00004000
Workqueue: usb_hub_wq hub_event
Call Trace:
 <TASK>
 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+0x1dd/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+0x9cc/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+0x5b6/0x6c0 arch/x86/kernel/process.c:148
 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: ffffffff892c7360 (rcu_read_lock){....}-{1:3}, at: rcu_lock_acquire include/linux/rcupdate.h:331 [inline]
 #0: ffffffff892c7360 (rcu_read_lock){....}-{1:3}, at: rcu_read_lock include/linux/rcupdate.h:841 [inline]
 #0: ffffffff892c7360 (rcu_read_lock){....}-{1:3}, at: debug_show_all_locks+0x36/0x1c0 kernel/locking/lockdep.c:6775
6 locks held by kworker/1:2/706:
 #0: ffff888106aae548 ((wq_completion)usb_hub_wq){+.+.}-{0:0}, at: process_one_work+0x12a2/0x1b70 kernel/workqueue.c:3211
 #1: ffffc90001a2fd10 ((work_completion)(&hub->events)){+.+.}-{0:0}
, at: process_one_work+0x929/0x1b70 kernel/workqueue.c:3212
 #2: ffff88810b7bd198
 (&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: 
ffff888111e53198 (&dev->mutex){....}-{4:4}, at: device_lock include/linux/device.h:911 [inline]
ffff888111e53198 (&dev->mutex){....}-{4:4}, at: __device_attach+0x7e/0x4b0 drivers/base/dd.c:1006
 #4: 
ffff88812944f160
 (&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
 #5: ffffffff8a5fa288 (rtnl_mutex){+.+.}-{4:4}, at: rtnl_net_lock_killable include/linux/rtnetlink.h:145 [inline]
 #5: ffffffff8a5fa288 (rtnl_mutex){+.+.}-{4:4}, at: register_netdev+0x18/0x50 net/core/dev.c:11319
3 locks held by dhcpcd/2886:
2 locks held by getty/2909:
 #0: 
ffff8881083ad0a0 (&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: ffff888134bffd58
 (&p->lock){+.+.}-{4:4}, at: seq_read_iter+0xe1/0x12c0 fs/seq_file.c:182
 #1: 
ffff88813c384c88 (&of->mutex
#2){+.+.}-{4:4}, at: kernfs_seq_start+0x4d/0x240 fs/kernfs/file.c:154
 #2: ffff88810e7e5c38 (kn->active#9){++++}-{0:0}
, at: kernfs_seq_start+0x71/0x240 fs/kernfs/file.c:155
 #3: ffff88811d5ce198
 (&dev->mutex){....}-{4:4}, at: device_lock_interruptible include/linux/device.h:916 [inline]
 (&dev->mutex){....}-{4:4}, at: manufacturer_show+0x26/0xa0 drivers/usb/core/sysfs.c:142
5 locks held by kworker/0:3/5215:
 #0: ffff888106aae548 ((wq_completion)usb_hub_wq){+.+.}-{0:0}, at: process_one_work+0x12a2/0x1b70 kernel/workqueue.c:3211
 #1: ffffc9000207fd10 ((work_completion)(&hub->events)){+.+.}-{0:0}
, at: process_one_work+0x929/0x1b70 kernel/workqueue.c:3212
 #2: ffff88810b75a198 (&dev->mutex
){....}-{4:4}, at: device_lock include/linux/device.h:911 [inline]
){....}-{4:4}, at: hub_event+0x1be/0x5060 drivers/usb/core/hub.c:5898
 #3: ffff88811a61b198 (&dev->mutex){....}-{4:4}, at: device_lock include/linux/device.h:911 [inline]
 #3: ffff88811a61b198 (&dev->mutex){....}-{4:4}, at: __device_attach+0x7e/0x4b0 drivers/base/dd.c:1006
 #4: ffff888112015160 (&dev->mutex){....}-{4:4}, at: device_lock include/linux/device.h:911 [inline]
 #4: ffff888112015160 (&dev->mutex){....}-{4:4}, at: __device_attach+0x7e/0x4b0 drivers/base/dd.c:1006
4 locks held by udevd/5828:
 #0: ffff88813fb701c8 (&p->lock){+.+.}-{4:4}
, at: seq_read_iter+0xe1/0x12c0 fs/seq_file.c:182
 #1: 
ffff88811e706888 (&of->mutex
#2){+.+.}-{4:4}, at: kernfs_seq_start+0x4d/0x240 fs/kernfs/file.c:154
 #2: ffff888119e8e968 (
kn->active#9){++++}-{0:0}, at: kernfs_seq_start+0x71/0x240 fs/kernfs/file.c:155
 #3: ffff888111e53198 (&dev->mutex){....}-{4:4}, at: device_lock_interruptible include/linux/device.h:916 [inline]
 #3: ffff888111e53198 (&dev->mutex){....}-{4:4}, at: manufacturer_show+0x26/0xa0 drivers/usb/core/sysfs.c:142
6 locks held by kworker/1:7/6211:
 #0: ffff888106aae548 ((wq_completion)usb_hub_wq
){+.+.}-{0:0}, at: process_one_work+0x12a2/0x1b70 kernel/workqueue.c:3211
 #1: ffffc900135c7d10 ((work_completion)(&hub->events)){+.+.}-{0:0}, at: process_one_work+0x929/0x1b70 kernel/workqueue.c:3212
 #2: ffff88810b3e1198 (&dev->mutex){....}-{4:4}, at: device_lock include/linux/device.h:911 [inline]
 #2: ffff88810b3e1198 (&dev->mutex){....}-{4:4}, at: hub_event+0x1be/0x5060 drivers/usb/core/hub.c:5898
 #3: 
ffff888116a75198 (&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: ffff88811706a160 (&dev->mutex){....}-{4:4}, at: device_lock include/linux/device.h:911 [inline]
 #4: ffff88811706a160 (&dev->mutex){....}-{4:4}, at: __device_driver_lock drivers/base/dd.c:1096 [inline]
 #4: ffff88811706a160 (&dev->mutex){....}-{4:4}, at: device_release_driver_internal+0xa4/0x620 drivers/base/dd.c:1294
 #5: ffffffff8a5fa288 (rtnl_mutex){+.+.}-{4:4}, at: rtnl_net_lock include/linux/rtnetlink.h:130 [inline]
 #5: ffffffff8a5fa288 (rtnl_mutex){+.+.}-{4:4}, at: rtnl_net_dev_lock+0x146/0x360 net/core/dev.c:2142
5 locks held by kworker/1:6/11220:
 #0: ffff888106aae548 (
(wq_completion)usb_hub_wq){+.+.}-{0:0}, at: process_one_work+0x12a2/0x1b70 kernel/workqueue.c:3211
 #1: ffffc90014a47d10 ((work_completion)(&hub->events)){+.+.}-{0:0}, at: process_one_work+0x929/0x1b70 kernel/workqueue.c:3212
 #2: ffff88810b705198 (&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: ffff88811d5ce198 (&dev->mutex){....}-{4:4}, at: device_lock include/linux/device.h:911 [inline]
 #3: ffff88811d5ce198 (&dev->mutex){....}-{4:4}, at: __device_attach+0x7e/0x4b0 drivers/base/dd.c:1006
 #4: ffff88811a22e160 (&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
3 locks held by kworker/u8:0/16696:
 #0: 
ffff888112139148 ((wq_completion)ipv6_addrconf){+.+.}-{0:0}, at: process_one_work+0x12a2/0x1b70 kernel/workqueue.c:3211
 #1: ffffc90014ebfd10 ((work_completion)(&(&net->ipv6.addr_chk_work)->work)
){+.+.}-{0:0}, at: process_one_work+0x929/0x1b70 kernel/workqueue.c:3212
 #2: ffffffff8a5fa288 (
rtnl_mutex){+.+.}-{4:4}, at: rtnl_net_lock include/linux/rtnetlink.h:130 [inline]
rtnl_mutex){+.+.}-{4:4}, at: addrconf_verify_work+0x12/0x30 net/ipv6/addrconf.c:4734
6 locks held by kworker/1:0/19896:
 #0: 
ffff888106aae548 ((wq_completion)usb_hub_wq
){+.+.}-{0:0}, at: process_one_work+0x12a2/0x1b70 kernel/workqueue.c:3211
 #1: ffffc90001e9fd10 ((work_completion)(&hub->events)
){+.+.}-{0:0}, at: process_one_work+0x929/0x1b70 kernel/workqueue.c:3212
 #2: ffff88810b79d198 (&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: ffff88810ff5e198
 (&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: ffff888116a70160 (&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: ffffffff8a5fa288 (rtnl_mutex){+.+.}-{4:4}
, at: rtnl_net_lock_killable include/linux/rtnetlink.h:145 [inline]
, at: register_netdev+0x18/0x50 net/core/dev.c:11319

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

NMI backtrace for cpu 0
CPU: 0 UID: 0 PID: 30 Comm: khungtaskd Not tainted syzkaller #0 PREEMPT(voluntary) 
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 07/12/2025
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: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+0x5b6/0x6c0 arch/x86/kernel/process.c:148
 ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:245
 </TASK>
Sending NMI from CPU 0 to CPUs 1:
NMI backtrace for cpu 1
CPU: 1 UID: 0 PID: 2886 Comm: dhcpcd Not tainted syzkaller #0 PREEMPT(voluntary) 
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 07/12/2025
RIP: 0010:check_preemption_disabled+0x3/0xe0 lib/smp_processor_id.c:13
Code: 65 8b 05 0c e9 54 05 85 c0 74 04 90 0f 0b 90 e9 53 fc ff ff 0f 1f 00 90 90 90 90 90 90 90 90 90 90 90 90 90 90 90 90 41 54 55 <53> 48 83 ec 08 65 8b 1d c5 ab 54 05 65 8b 05 ba ab 54 05 a9 ff ff
RSP: 0018:ffffc900001a8a08 EFLAGS: 00000046
RAX: 0000000000000001 RBX: ffff888100f4c548 RCX: 0000000000000001
RDX: 0000000000000000 RSI: ffffffff88d06ace RDI: ffffffff878963e0
RBP: ffffffff892c7360 R08: 3cf5816934a91334 R09: 0000000000000000
R10: 0000000000000004 R11: 0000000000000000 R12: ffff888100f4ba00
R13: 0000000000000001 R14: 00000000ffffffff R15: 0000000000000004
FS:  00007f6ba648e740(0000) GS:ffff888268ff9000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 0000200000001e40 CR3: 000000011696e000 CR4: 00000000003506f0
Call Trace:
 <IRQ>
 lockdep_recursion_finish kernel/locking/lockdep.c:470 [inline]
 lock_is_held_type+0xdf/0x150 kernel/locking/lockdep.c:5941
 select_task_rq_fair+0x8a9/0x3ee0 kernel/sched/fair.c:8506
 select_task_rq kernel/sched/core.c:3607 [inline]
 try_to_wake_up+0x53f/0x1480 kernel/sched/core.c:4316
 call_timer_fn+0x197/0x620 kernel/time/timer.c:1747
 expire_timers kernel/time/timer.c:1798 [inline]
 __run_timers+0x6ef/0x960 kernel/time/timer.c:2372
 __run_timer_base kernel/time/timer.c:2384 [inline]
 __run_timer_base kernel/time/timer.c:2376 [inline]
 run_timer_base+0x114/0x190 kernel/time/timer.c:2393
 run_timer_softirq+0x1a/0x40 kernel/time/timer.c:2403
 handle_softirqs+0x208/0x8d0 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:1050 [inline]
 sysvec_apic_timer_interrupt+0x90/0xb0 arch/x86/kernel/apic/apic.c:1050
 </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 44 7b 20 00 9c 5d 81 e5 00 02 00 00 31 ff 48 89 ee e8 a2 76 20 00 48 85 ed 0f 85 25 01 00 00 <e8> 24 7b 20 00 45 31 c9 41 b8 01 00 00 00 31 c9 48 8d 05 00 00 00
RSP: 0018:ffffc9000158f268 EFLAGS: 00000293
RAX: 0000000000000000 RBX: 0000000000000039 RCX: ffffffff815d7e3c
RDX: ffff888100f4ba00 RSI: ffffffff815d7e46 RDI: 0000000000000007
RBP: 0000000000000000 R08: 0000000000000007 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000000 R12: 1ffff920002b1e4f
R13: 0000000000000200 R14: ffff888102685700 R15: ffffc9000158f330
 dev_vprintk_emit drivers/base/core.c:4914 [inline]
 dev_printk_emit+0xfa/0x140 drivers/base/core.c:4925
 __netdev_printk+0x1fb/0x500 net/core/dev.c:12598
 netdev_err+0xe4/0x120 net/core/dev.c:12650
 asix_set_sw_mii drivers/net/usb/asix_common.c:78 [inline]
 asix_check_host_enable+0x18f/0x240 drivers/net/usb/asix_common.c:98
 __asix_mdio_read+0x9c/0x260 drivers/net/usb/asix_common.c:484
 asix_phy_reset+0x106/0x1f0 drivers/net/usb/asix_devices.c:215
 ax88178_reset+0x42d/0x12f0 drivers/net/usb/asix_devices.c:1125
 usbnet_open+0xcc/0xbe0 drivers/net/usb/usbnet.c:910
 __dev_open+0x3a0/0x850 net/core/dev.c:1682
 __dev_change_flags+0x55d/0x720 net/core/dev.c:9549
 netif_change_flags+0x8d/0x160 net/core/dev.c:9612
 dev_change_flags+0xb6/0x170 net/core/dev_api.c:68
 devinet_ioctl+0x11d5/0x1f50 net/ipv4/devinet.c:1200
 inet_ioctl+0x3a7/0x3f0 net/ipv4/af_inet.c:1001
 sock_do_ioctl+0x118/0x280 net/socket.c:1238
 sock_ioctl+0x42f/0x6a0 net/socket.c:1359
 vfs_ioctl fs/ioctl.c:51 [inline]
 __do_sys_ioctl fs/ioctl.c:598 [inline]
 __se_sys_ioctl fs/ioctl.c:584 [inline]
 __x64_sys_ioctl+0x18b/0x210 fs/ioctl.c:584
 do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline]
 do_syscall_64+0xcd/0x4b0 arch/x86/entry/syscall_64.c:94
 entry_SYSCALL_64_after_hwframe+0x77/0x7f
RIP: 0033:0x7f6ba658e378
Code: 00 00 48 8d 44 24 08 48 89 54 24 e0 48 89 44 24 c0 48 8d 44 24 d0 48 89 44 24 c8 b8 10 00 00 00 c7 44 24 b8 10 00 00 00 0f 05 <89> c2 3d 00 f0 ff ff 77 07 89 d0 c3 0f 1f 40 00 48 8b 15 49 3a 0d
RSP: 002b:00007ffefad4c228 EFLAGS: 00000246 ORIG_RAX: 0000000000000010
RAX: ffffffffffffffda RBX: 0000000000000008 RCX: 00007f6ba658e378
RDX: 00007ffefad5c420 RSI: 0000000000008914 RDI: 0000000000000008
RBP: 0000000000000000 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 00007ffefad6c5c0
R13: 00007f6ba648e6c8 R14: 0000000000000028 R15: 0000000000008914
 </TASK>