syzbot

INFO: task kworker/1:7:7813 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:22840 pid:7813  tgid:7813  ppid:2      task_flags:0x4288060 flags:0x00080000
Workqueue: usb_hub_wq hub_event

Call Trace:
 <TASK>
 context_switch kernel/sched/core.c:5256 [inline]
 __schedule+0x145d/0x4a00 kernel/sched/core.c:6863
 __schedule_loop kernel/sched/core.c:6945 [inline]
 schedule+0xe7/0x3a0 kernel/sched/core.c:6960
 schedule_preempt_disabled+0x13/0x30 kernel/sched/core.c:7017
 __mutex_lock_common kernel/locking/mutex.c:692 [inline]
 __mutex_lock+0xc69/0x1ca0 kernel/locking/mutex.c:776
 rtnl_net_lock include/linux/rtnetlink.h:130 [inline]
 rtnl_net_dev_lock+0x146/0x360 net/core/dev.c:2143
 unregister_netdev+0x15/0x60 net/core/dev.c:12461
 usbnet_disconnect+0x109/0x510 drivers/net/usb/usbnet.c:1676
 usb_unbind_interface+0x1dd/0x9e0 drivers/usb/core/driver.c:458
 device_remove drivers/base/dd.c:571 [inline]
 device_remove+0x125/0x170 drivers/base/dd.c:563
 __device_release_driver drivers/base/dd.c:1282 [inline]
 device_release_driver_internal+0x44b/0x620 drivers/base/dd.c:1305
 bus_remove_device+0x22f/0x450 drivers/base/bus.c:616
 device_del+0x396/0x9f0 drivers/base/core.c:3878
 usb_disable_device+0x355/0x820 drivers/usb/core/message.c:1418
 usb_disconnect+0x2e1/0x9e0 drivers/usb/core/hub.c:2345
 hub_port_connect drivers/usb/core/hub.c:5407 [inline]
 hub_port_connect_change drivers/usb/core/hub.c:5707 [inline]
 port_event drivers/usb/core/hub.c:5871 [inline]
 hub_event+0x1b50/0x5420 drivers/usb/core/hub.c:5953
 process_one_work+0x9ba/0x1b20 kernel/workqueue.c:3257
 process_scheduled_works kernel/workqueue.c:3340 [inline]
 worker_thread+0x6c8/0xf10 kernel/workqueue.c:3421
 kthread+0x3c5/0x780 kernel/kthread.c:463
 ret_from_fork+0x74f/0xa30 arch/x86/kernel/process.c:158
 ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:246
 </TASK>
INFO: task kworker/u8:1:16977 blocked for more than 143 seconds.
      Not tainted syzkaller #0
"echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message.
task:kworker/u8:1    state:D stack:26072 pid:16977 tgid:16977 ppid:2      task_flags:0x4208060 flags:0x00080000
Workqueue: ipv6_addrconf addrconf_verify_work
Call Trace:
 <TASK>
 context_switch kernel/sched/core.c:5256 [inline]
 __schedule+0x145d/0x4a00 kernel/sched/core.c:6863
 __schedule_loop kernel/sched/core.c:6945 [inline]
 schedule+0xe7/0x3a0 kernel/sched/core.c:6960
 schedule_preempt_disabled+0x13/0x30 kernel/sched/core.c:7017
 __mutex_lock_common kernel/locking/mutex.c:692 [inline]
 __mutex_lock+0xc69/0x1ca0 kernel/locking/mutex.c:776
 rtnl_net_lock include/linux/rtnetlink.h:130 [inline]
 addrconf_verify_work+0x12/0x30 net/ipv6/addrconf.c:4734
 process_one_work+0x9ba/0x1b20 kernel/workqueue.c:3257
 process_scheduled_works kernel/workqueue.c:3340 [inline]
 worker_thread+0x6c8/0xf10 kernel/workqueue.c:3421
 kthread+0x3c5/0x780 kernel/kthread.c:463
 ret_from_fork+0x74f/0xa30 arch/x86/kernel/process.c:158
 ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:246
 </TASK>

Showing all locks held in the system:
1 lock held by khungtaskd/30:
 #0: ffffffff892cd760 (rcu_read_lock){....}-{1:3}, at: rcu_lock_acquire include/linux/rcupdate.h:331 [inline]
 #0: ffffffff892cd760 (rcu_read_lock){....}-{1:3}, at: rcu_read_lock include/linux/rcupdate.h:867 [inline]
 #0: ffffffff892cd760 (rcu_read_lock){....}-{1:3}, at: debug_show_all_locks+0x36/0x1c0 kernel/locking/lockdep.c:6775
6 locks held by kworker/1:1/43:
 #0: ffff888105283548 ((wq_completion)usb_hub_wq){+.+.}-{0:0}, at: process_one_work+0x128d/0x1b20 kernel/workqueue.c:3232
 #1: ffffc900004e7ca0 ((work_completion)(&hub->events)){+.+.}-{0:0}
, at: process_one_work+0x914/0x1b20 kernel/workqueue.c:3233
 #2: ffff88810abae198 (&dev->mutex){....}-{4:4}, at: device_lock include/linux/device.h:895 [inline]
 #2: ffff88810abae198 (&dev->mutex){....}-{4:4}, at: hub_event+0x1be/0x5420 drivers/usb/core/hub.c:5899
 #3: ffff88813a93a198 (&dev->mutex){....}-{4:4}, at: device_lock include/linux/device.h:895 [inline]
 #3: ffff88813a93a198 (&dev->mutex){....}-{4:4}, at: __device_attach+0x7e/0x4e0 drivers/base/dd.c:1006
 #4: ffff888134c66160 (
&dev->mutex){....}-{4:4}, at: device_lock include/linux/device.h:895 [inline]
&dev->mutex){....}-{4:4}, at: __device_attach+0x7e/0x4e0 drivers/base/dd.c:1006
 #5: ffffffff8a666c68 (rtnl_mutex
){+.+.}-{4:4}, at: wiphy_apply_custom_regulatory+0x23d/0x3c0 net/wireless/reg.c:2624
1 lock held by dhcpcd/2902:
2 locks held by getty/2925:
 #0: ffff8881012830a0 (&tty->ldisc_sem){++++}-{0:0}, at: tty_ldisc_ref_wait+0x24/0x80 drivers/tty/tty_ldisc.c:243
 #1: ffffc900000452f0 (&ldata->atomic_read_lock){+.+.}-{4:4}, at: n_tty_read+0x41b/0x1510 drivers/tty/n_tty.c:2211
6 locks held by kworker/1:3/5226:
 #0: ffff888105283548 ((wq_completion)usb_hub_wq){+.+.}-{0:0}, at: process_one_work+0x128d/0x1b20 kernel/workqueue.c:3232
 #1: ffffc900020bfca0 ((work_completion)(&hub->events)){+.+.}-{0:0}
, at: process_one_work+0x914/0x1b20 kernel/workqueue.c:3233
 #2: ffff88810ab86198 (&dev->mutex){....}-{4:4}, at: device_lock include/linux/device.h:895 [inline]
 #2: ffff88810ab86198 (&dev->mutex){....}-{4:4}, at: hub_event+0x1be/0x5420 drivers/usb/core/hub.c:5899
 #3: ffff888112ee8198 (&dev->mutex){....}-{4:4}, at: device_lock include/linux/device.h:895 [inline]
 #3: ffff888112ee8198 (&dev->mutex){....}-{4:4}, at: __device_attach+0x7e/0x4e0 drivers/base/dd.c:1006
 #4: ffff888130e8a160 (&dev->mutex){....}-{4:4}, at: device_lock include/linux/device.h:895 [inline]
 #4: ffff888130e8a160 (&dev->mutex){....}-{4:4}, at: __device_attach+0x7e/0x4e0 drivers/base/dd.c:1006
 #5: ffffffff8a666c68 (
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:11504
6 locks held by kworker/1:7/7813:
 #0: ffff888105283548
 ((wq_completion)usb_hub_wq){+.+.}-{0:0}, at: process_one_work+0x128d/0x1b20 kernel/workqueue.c:3232
 #1: ffffc90015c5fca0 ((work_completion)(&hub->events)){+.+.}-{0:0}, at: process_one_work+0x914/0x1b20 kernel/workqueue.c:3233
 #2: 
ffff88810ab9e198 (&dev->mutex){....}-{4:4}, at: device_lock include/linux/device.h:895 [inline]
ffff88810ab9e198 (&dev->mutex){....}-{4:4}, at: hub_event+0x1be/0x5420 drivers/usb/core/hub.c:5899
 #3: ffff88812bf63198 (&dev->mutex
){....}-{4:4}, at: device_lock include/linux/device.h:895 [inline]
){....}-{4:4}, at: usb_disconnect+0x10a/0x9e0 drivers/usb/core/hub.c:2336
 #4: ffff88812eac5160 (&dev->mutex){....}-{4:4}, at: device_lock include/linux/device.h:895 [inline]
 #4: ffff88812eac5160 (&dev->mutex){....}-{4:4}, at: __device_driver_lock drivers/base/dd.c:1104 [inline]
 #4: ffff88812eac5160 (&dev->mutex){....}-{4:4}, at: device_release_driver_internal+0xa4/0x620 drivers/base/dd.c:1302
 #5: ffffffff8a666c68 (rtnl_mutex){+.+.}-{4:4}, at: rtnl_net_lock include/linux/rtnetlink.h:130 [inline]
 #5: ffffffff8a666c68 (rtnl_mutex){+.+.}-{4:4}, at: rtnl_net_dev_lock+0x146/0x360 net/core/dev.c:2143
4 locks held by udevd/10885:
 #0: ffff888124c1fb08 (&p->lock){+.+.}-{4:4}, at: seq_read_iter+0xe1/0x12d0 fs/seq_file.c:182
 #1: ffff88811944fc88 (&of->mutex#2){+.+.}-{4:4}, at: kernfs_seq_start+0x4f/0x2a0 fs/kernfs/file.c:172
 #2: ffff888113b774b8 (kn->active#18){++++}-{0:0}, at: kernfs_get_active_of fs/kernfs/file.c:80 [inline]
 #2: ffff888113b774b8 (kn->active#18){++++}-{0:0}, at: kernfs_seq_start+0xbc/0x2a0 fs/kernfs/file.c:173
 #3: ffff88813a93a198 (&dev->mutex){....}-{4:4}
, at: device_lock_interruptible include/linux/device.h:900 [inline]
, at: manufacturer_show+0x26/0xa0 drivers/usb/core/sysfs.c:142
3 locks held by kworker/u8:1/16977:
 #0: ffff888112373148 (
(wq_completion)ipv6_addrconf){+.+.}-{0:0}, at: process_one_work+0x128d/0x1b20 kernel/workqueue.c:3232
 #1: ffffc90002e9fca0 ((work_completion)(&(&net->ipv6.addr_chk_work)->work)){+.+.}-{0:0}, at: process_one_work+0x914/0x1b20 kernel/workqueue.c:3233
 #2: 
ffffffff8a666c68 (rtnl_mutex){+.+.}-{4:4}, at: rtnl_net_lock include/linux/rtnetlink.h:130 [inline]
ffffffff8a666c68 (rtnl_mutex){+.+.}-{4:4}, at: addrconf_verify_work+0x12/0x30 net/ipv6/addrconf.c:4734
6 locks held by kworker/1:8/19386:
 #0: 
ffff888105283548 ((wq_completion)usb_hub_wq){+.+.}-{0:0}, at: process_one_work+0x128d/0x1b20 kernel/workqueue.c:3232
 #1: ffffc90004517ca0 ((work_completion)(&hub->events)
){+.+.}-{0:0}, at: process_one_work+0x914/0x1b20 kernel/workqueue.c:3233
 #2: ffff88810a797198 (&dev->mutex){....}-{4:4}, at: device_lock include/linux/device.h:895 [inline]
 #2: ffff88810a797198 (&dev->mutex){....}-{4:4}, at: hub_event+0x1be/0x5420 drivers/usb/core/hub.c:5899
 #3: ffff88811ce90198 (&dev->mutex){....}-{4:4}, at: device_lock include/linux/device.h:895 [inline]
 #3: ffff88811ce90198 (&dev->mutex){....}-{4:4}, at: __device_attach+0x7e/0x4e0 drivers/base/dd.c:1006
 #4: ffff88814478a160 (
&dev->mutex){....}-{4:4}, at: device_lock include/linux/device.h:895 [inline]
&dev->mutex){....}-{4:4}, at: __device_attach+0x7e/0x4e0 drivers/base/dd.c:1006
 #5: ffffffff8a666c68 (rtnl_mutex){+.+.}-{4:4}
, at: rtnl_net_lock_killable include/linux/rtnetlink.h:145 [inline]
, at: register_netdev+0x18/0x50 net/core/dev.c:11504

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

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 10/25/2025
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]
 __sys_info lib/sys_info.c:157 [inline]
 sys_info+0x133/0x180 lib/sys_info.c:165
 check_hung_uninterruptible_tasks kernel/hung_task.c:346 [inline]
 watchdog+0xe66/0x1180 kernel/hung_task.c:515
 kthread+0x3c5/0x780 kernel/kthread.c:463
 ret_from_fork+0x74f/0xa30 arch/x86/kernel/process.c:158
 ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:246
 </TASK>
Sending NMI from CPU 1 to CPUs 0:
NMI backtrace for cpu 0
CPU: 0 UID: 0 PID: 2902 Comm: dhcpcd Not tainted syzkaller #0 PREEMPT(voluntary) 
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 10/25/2025
RIP: 0010:match_held_lock+0x0/0xb0 kernel/locking/lockdep.c:5305
Code: 9b 34 ce 88 67 48 0f b9 3a 90 31 db eb c4 66 66 2e 0f 1f 84 00 00 00 00 00 90 90 90 90 90 90 90 90 90 90 90 90 90 90 90 90 90 <53> 48 89 fb 48 39 77 10 74 55 66 83 7f 22 1f 76 65 48 8b 46 08 48
RSP: 0018:ffffc90000007b88 EFLAGS: 00000093
RAX: 0000000000000005 RBX: ffff88810beda810 RCX: 0000000000000001
RDX: 0000000000000000 RSI: ffffffff892cd6a0 RDI: ffff88810beda810
RBP: ffffffff892cd6a0 R08: 0000000000000000 R09: fffffbfff154921a
R10: ffffffff8aa490d7 R11: ffff88810beda7e8 R12: ffff88810bed9d40
R13: ffff88810beda7e8 R14: 00000000ffffffff R15: 0000000000000001
FS:  00007f5bafc3e740(0000) GS:ffff888268bf4000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 00007fb7f00f3000 CR3: 0000000117008000 CR4: 00000000003506f0
Call Trace:
 <IRQ>
 __lock_is_held kernel/locking/lockdep.c:5601 [inline]
 lock_is_held_type+0xb0/0x150 kernel/locking/lockdep.c:5940
 lock_is_held include/linux/lockdep.h:249 [inline]
 rcu_read_lock_sched_held kernel/rcu/update.c:126 [inline]
 rcu_read_lock_sched_held+0x3e/0x70 kernel/rcu/update.c:120
 task_css_set include/linux/cgroup.h:447 [inline]
 task_dfl_cgroup include/linux/cgroup.h:516 [inline]
 cgroup_account_cputime include/linux/cgroup.h:744 [inline]
 update_se+0x4c7/0x690 kernel/sched/fair.c:1163
 update_curr+0x71/0x570 kernel/sched/fair.c:1209
 enqueue_entity kernel/sched/fair.c:5228 [inline]
 enqueue_task_fair+0x2b7/0x21f0 kernel/sched/fair.c:6932
 enqueue_task+0xd0/0x270 kernel/sched/core.c:2094
 activate_task kernel/sched/core.c:2135 [inline]
 ttwu_do_activate+0x12e/0x890 kernel/sched/core.c:3631
 ttwu_queue kernel/sched/core.c:3894 [inline]
 try_to_wake_up+0x72d/0x1480 kernel/sched/core.c:4218
 hrtimer_wakeup+0x47/0x60 kernel/time/hrtimer.c:2013
 __run_hrtimer kernel/time/hrtimer.c:1777 [inline]
 __hrtimer_run_queues+0x202/0xc40 kernel/time/hrtimer.c:1841
 hrtimer_interrupt+0x397/0x8e0 kernel/time/hrtimer.c:1903
 local_apic_timer_interrupt arch/x86/kernel/apic/apic.c:1045 [inline]
 __sysvec_apic_timer_interrupt+0x10b/0x3c0 arch/x86/kernel/apic/apic.c:1062
 instr_sysvec_apic_timer_interrupt arch/x86/kernel/apic/apic.c:1056 [inline]
 sysvec_apic_timer_interrupt+0x8b/0xb0 arch/x86/kernel/apic/apic.c:1056
 </IRQ>
 <TASK>
 asm_sysvec_apic_timer_interrupt+0x1a/0x20 arch/x86/include/asm/idtentry.h:697
RIP: 0010:console_trylock_spinning kernel/printk/printk.c:2037 [inline]
RIP: 0010:vprintk_emit+0x556/0x6b0 kernel/printk/printk.c:2425
Code: 00 4d 85 ed 0f 85 19 01 00 00 e8 25 1e 21 00 9c 5d 81 e5 00 02 00 00 31 ff 48 89 ee e8 e3 18 21 00 48 85 ed 0f 85 25 01 00 00 <e8> 05 1e 21 00 45 31 c9 41 b8 01 00 00 00 31 c9 48 8d 05 00 00 00
RSP: 0018:ffffc900015ef218 EFLAGS: 00000293
RAX: 0000000000000000 RBX: 000000000000003a RCX: ffffffff815ed27b
RDX: ffff88810bed9d40 RSI: ffffffff815ed285 RDI: 0000000000000007
RBP: 0000000000000000 R08: 0000000000000007 R09: 0000000000000000
R10: 0000000000000000 R11: ffff88810beda7e8 R12: 1ffff920002bde45
R13: 0000000000000200 R14: ffff8881022e57c0 R15: ffffc900015ef2e0
 dev_vprintk_emit drivers/base/core.c:4914 [inline]
 dev_printk_emit+0xfa/0x140 drivers/base/core.c:4925
 __netdev_printk+0x1ff/0x480 net/core/dev.c:12901
 netdev_warn+0xe4/0x120 net/core/dev.c:12954
 asix_write_cmd+0xf1/0x100 drivers/net/usb/asix_common.c:57
 asix_set_sw_mii drivers/net/usb/asix_common.c:75 [inline]
 asix_check_host_enable+0x154/0x240 drivers/net/usb/asix_common.c:98
 __asix_mdio_read+0x9c/0x290 drivers/net/usb/asix_common.c:484
 asix_phy_reset+0x106/0x1f0 drivers/net/usb/asix_devices.c:215
 ax88178_reset+0x42d/0x1490 drivers/net/usb/asix_devices.c:1153
 usbnet_open+0xcf/0xcc0 drivers/net/usb/usbnet.c:914
 __dev_open+0x3a3/0x7f0 net/core/dev.c:1683
 __dev_change_flags+0x55d/0x6f0 net/core/dev.c:9734
 netif_change_flags+0x8d/0x160 net/core/dev.c:9797
 dev_change_flags+0xb6/0x170 net/core/dev_api.c:68
 devinet_ioctl+0x11d5/0x1f30 net/ipv4/devinet.c:1199
 inet_ioctl+0x3a7/0x3f0 net/ipv4/af_inet.c:1009
 sock_do_ioctl+0x118/0x280 net/socket.c:1254
 sock_ioctl+0x42f/0x6a0 net/socket.c:1375
 vfs_ioctl fs/ioctl.c:51 [inline]
 __do_sys_ioctl fs/ioctl.c:597 [inline]
 __se_sys_ioctl fs/ioctl.c:583 [inline]
 __x64_sys_ioctl+0x18e/0x210 fs/ioctl.c:583
 do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline]
 do_syscall_64+0xcd/0x570 arch/x86/entry/syscall_64.c:94
 entry_SYSCALL_64_after_hwframe+0x77/0x7f
RIP: 0033:0x7f5bafd3e378
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:00007ffcbb64e9f8 EFLAGS: 00000246 ORIG_RAX: 0000000000000010
RAX: ffffffffffffffda RBX: 0000000000000008 RCX: 00007f5bafd3e378
RDX: 00007ffcbb65ebf0 RSI: 0000000000008914 RDI: 0000000000000008
RBP: 0000000000000000 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 00007ffcbb66ed90
R13: 00007f5bafc3e6c8 R14: 0000000000000028 R15: 0000000000008914
 </TASK>