INFO: task kworker/0:4:11516 blocked for more than 143 seconds. Not tainted 6.8.0-rc6-syzkaller-00189-gd99e42ce6b83 #0 "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message. task:kworker/0:4 state:D stack:22880 pid:11516 tgid:11516 ppid:2 flags:0x00004000 Workqueue: usb_hub_wq hub_event Call Trace: context_switch kernel/sched/core.c:5400 [inline] __schedule+0xca8/0x3100 kernel/sched/core.c:6727 __schedule_loop kernel/sched/core.c:6802 [inline] schedule+0xe9/0x270 kernel/sched/core.c:6817 schedule_preempt_disabled+0x13/0x20 kernel/sched/core.c:6874 __mutex_lock_common kernel/locking/mutex.c:684 [inline] __mutex_lock+0x5b9/0x9d0 kernel/locking/mutex.c:752 unregister_netdev+0x12/0x30 net/core/dev.c:11156 r871xu_dev_remove+0x28e/0x480 drivers/staging/rtl8712/usb_intf.c:596 usb_unbind_interface+0x1e5/0x960 drivers/usb/core/driver.c:461 device_remove drivers/base/dd.c:569 [inline] device_remove+0x11f/0x170 drivers/base/dd.c:561 __device_release_driver drivers/base/dd.c:1272 [inline] device_release_driver_internal+0x44a/0x610 drivers/base/dd.c:1295 bus_remove_device+0x22c/0x420 drivers/base/bus.c:574 device_del+0x39a/0xa50 drivers/base/core.c:3828 usb_disable_device+0x36c/0x7f0 drivers/usb/core/message.c:1418 usb_disconnect+0x2e1/0x910 drivers/usb/core/hub.c:2296 hub_port_connect drivers/usb/core/hub.c:5352 [inline] hub_port_connect_change drivers/usb/core/hub.c:5652 [inline] port_event drivers/usb/core/hub.c:5812 [inline] hub_event+0x1be0/0x4f40 drivers/usb/core/hub.c:5894 process_one_work+0x886/0x15d0 kernel/workqueue.c:2633 process_scheduled_works kernel/workqueue.c:2706 [inline] worker_thread+0x8b9/0x1290 kernel/workqueue.c:2787 kthread+0x2c6/0x3a0 kernel/kthread.c:388 ret_from_fork+0x45/0x80 arch/x86/kernel/process.c:147 ret_from_fork_asm+0x11/0x20 arch/x86/entry/entry_64.S:243 Showing all locks held in the system: 6 locks held by kworker/0:1/9: #0: ffff888106292d38 ((wq_completion)usb_hub_wq){+.+.}-{0:0}, at: process_one_work+0x789/0x15d0 kernel/workqueue.c:2608 #1: ffffc9000009fd80 ((work_completion)(&hub->events)){+.+.}-{0:0}, at: process_one_work+0x7eb/0x15d0 kernel/workqueue.c:2609 #2: ffff88810b3c0190 (&dev->mutex){....}-{3:3}, at: device_lock include/linux/device.h:990 [inline] #2: ffff88810b3c0190 (&dev->mutex){....}-{3:3}, at: hub_event+0x1be/0x4f40 drivers/usb/core/hub.c:5840 #3: ffff88813b026190 (&dev->mutex){....}-{3:3}, at: device_lock include/linux/device.h:990 [inline] #3: ffff88813b026190 (&dev->mutex){....}-{3:3}, at: __device_attach+0x7f/0x4b0 drivers/base/dd.c:1005 #4: ffff888105abf160 (&dev->mutex){....}-{3:3}, at: device_lock include/linux/device.h:990 [inline] #4: ffff888105abf160 (&dev->mutex){....}-{3:3}, at: __device_attach+0x7f/0x4b0 drivers/base/dd.c:1005 #5: ffffffff88fd2768 (rtnl_mutex){+.+.}-{3:3}, at: register_netdev+0x13/0x50 net/core/dev.c:10391 5 locks held by kworker/1:0/22: #0: ffff888106292d38 ((wq_completion)usb_hub_wq){+.+.}-{0:0}, at: process_one_work+0x789/0x15d0 kernel/workqueue.c:2608 #1: ffffc9000017fd80 ((work_completion)(&hub->events)){+.+.}-{0:0}, at: process_one_work+0x7eb/0x15d0 kernel/workqueue.c:2609 #2: ffff88810b348190 (&dev->mutex){....}-{3:3}, at: device_lock include/linux/device.h:990 [inline] #2: ffff88810b348190 (&dev->mutex){....}-{3:3}, at: hub_event+0x1be/0x4f40 drivers/usb/core/hub.c:5840 #3: ffff888111665190 (&dev->mutex){....}-{3:3}, at: device_lock include/linux/device.h:990 [inline] #3: ffff888111665190 (&dev->mutex){....}-{3:3}, at: usb_disconnect+0x10a/0x910 drivers/usb/core/hub.c:2287 #4: ffff88811a17d160 (&dev->mutex){....}-{3:3}, at: device_lock include/linux/device.h:990 [inline] #4: ffff88811a17d160 (&dev->mutex){....}-{3:3}, at: __device_driver_lock drivers/base/dd.c:1095 [inline] #4: ffff88811a17d160 (&dev->mutex){....}-{3:3}, at: device_release_driver_internal+0xa4/0x610 drivers/base/dd.c:1292 1 lock held by khungtaskd/29: #0: ffffffff87eadc20 (rcu_read_lock){....}-{1:2}, at: rcu_lock_acquire include/linux/rcupdate.h:298 [inline] #0: ffffffff87eadc20 (rcu_read_lock){....}-{1:2}, at: rcu_read_lock include/linux/rcupdate.h:750 [inline] #0: ffffffff87eadc20 (rcu_read_lock){....}-{1:2}, at: debug_show_all_locks+0x75/0x340 kernel/locking/lockdep.c:6614 3 locks held by kworker/0:2/726: 2 locks held by dhcpcd/2430: #0: ffffffff88fd2768 (rtnl_mutex){+.+.}-{3:3}, at: devinet_ioctl+0x1d3/0x1f10 net/ipv4/devinet.c:1091 #1: ffff88813a66cd90 (&padapter->mutex_start){+.+.}-{3:3}, at: netdev_open+0x32/0x820 drivers/staging/rtl8712/os_intfs.c:391 2 locks held by getty/2450: #0: ffff8881149910a0 (&tty->ldisc_sem){++++}-{0:0}, at: tty_ldisc_ref_wait+0x24/0x80 drivers/tty/tty_ldisc.c:243 #1: ffffc900000432f0 (&ldata->atomic_read_lock){+.+.}-{3:3}, at: n_tty_read+0xfc6/0x1490 drivers/tty/n_tty.c:2201 4 locks held by udevd/4797: #0: ffff88811a22a0a0 (&p->lock){+.+.}-{3:3}, at: seq_read_iter+0xda/0x1280 fs/seq_file.c:182 #1: ffff88811e4dd488 (&of->mutex){+.+.}-{3:3}, at: kernfs_seq_start+0x4d/0x230 fs/kernfs/file.c:154 #2: ffff888115e3bba8 (kn->active#31){.+.+}-{0:0}, at: kernfs_seq_start+0x71/0x230 fs/kernfs/file.c:155 #3: ffff888121572190 (&dev->mutex){....}-{3:3}, at: device_lock_interruptible include/linux/device.h:995 [inline] #3: ffff888121572190 (&dev->mutex){....}-{3:3}, at: serial_show+0x26/0xa0 drivers/usb/core/sysfs.c:143 3 locks held by kworker/0:7/6770: #0: ffff88810e7b5d38 ((wq_completion)ipv6_addrconf){+.+.}-{0:0}, at: process_one_work+0x789/0x15d0 kernel/workqueue.c:2608 #1: ffffc900077a7d80 ((work_completion)(&(&net->ipv6.addr_chk_work)->work)){+.+.}-{0:0}, at: process_one_work+0x7eb/0x15d0 kernel/workqueue.c:2609 #2: ffffffff88fd2768 (rtnl_mutex){+.+.}-{3:3}, at: addrconf_verify_work+0x12/0x30 net/ipv6/addrconf.c:4686 6 locks held by kworker/1:6/10222: #0: ffff888106292d38 ((wq_completion)usb_hub_wq){+.+.}-{0:0}, at: process_one_work+0x789/0x15d0 kernel/workqueue.c:2608 #1: ffffc900067d7d80 ((work_completion)(&hub->events)){+.+.}-{0:0}, at: process_one_work+0x7eb/0x15d0 kernel/workqueue.c:2609 #2: ffff88810afb8190 (&dev->mutex){....}-{3:3}, at: device_lock include/linux/device.h:990 [inline] #2: ffff88810afb8190 (&dev->mutex){....}-{3:3}, at: hub_event+0x1be/0x4f40 drivers/usb/core/hub.c:5840 #3: ffff888121572190 (&dev->mutex){....}-{3:3}, at: device_lock include/linux/device.h:990 [inline] #3: ffff888121572190 (&dev->mutex){....}-{3:3}, at: __device_attach+0x7f/0x4b0 drivers/base/dd.c:1005 #4: ffff88811efd7160 (&dev->mutex){....}-{3:3}, at: device_lock include/linux/device.h:990 [inline] #4: ffff88811efd7160 (&dev->mutex){....}-{3:3}, at: __device_attach+0x7f/0x4b0 drivers/base/dd.c:1005 #5: ffffffff88fd2768 (rtnl_mutex){+.+.}-{3:3}, at: register_netdev+0x13/0x50 net/core/dev.c:10391 6 locks held by kworker/0:4/11516: #0: ffff888106292d38 ((wq_completion)usb_hub_wq){+.+.}-{0:0}, at: process_one_work+0x789/0x15d0 kernel/workqueue.c:2608 #1: ffffc900016ffd80 ((work_completion)(&hub->events)){+.+.}-{0:0}, at: process_one_work+0x7eb/0x15d0 kernel/workqueue.c:2609 #2: ffff88810b3a8190 (&dev->mutex){....}-{3:3}, at: device_lock include/linux/device.h:990 [inline] #2: ffff88810b3a8190 (&dev->mutex){....}-{3:3}, at: hub_event+0x1be/0x4f40 drivers/usb/core/hub.c:5840 #3: ffff88810733f190 (&dev->mutex){....}-{3:3}, at: device_lock include/linux/device.h:990 [inline] #3: ffff88810733f190 (&dev->mutex){....}-{3:3}, at: usb_disconnect+0x10a/0x910 drivers/usb/core/hub.c:2287 #4: ffff888105784160 (&dev->mutex){....}-{3:3}, at: device_lock include/linux/device.h:990 [inline] #4: ffff888105784160 (&dev->mutex){....}-{3:3}, at: __device_driver_lock drivers/base/dd.c:1095 [inline] #4: ffff888105784160 (&dev->mutex){....}-{3:3}, at: device_release_driver_internal+0xa4/0x610 drivers/base/dd.c:1292 #5: ffffffff88fd2768 (rtnl_mutex){+.+.}-{3:3}, at: unregister_netdev+0x12/0x30 net/core/dev.c:11156 3 locks held by kworker/1:7/12213: #0: ffff88810e7b5d38 ((wq_completion)ipv6_addrconf){+.+.}-{0:0}, at: process_one_work+0x789/0x15d0 kernel/workqueue.c:2608 #1: ffffc9000510fd80 ((work_completion)(&(&net->ipv6.addr_chk_work)->work)){+.+.}-{0:0}, at: process_one_work+0x7eb/0x15d0 kernel/workqueue.c:2609 #2: ffffffff88fd2768 (rtnl_mutex){+.+.}-{3:3}, at: addrconf_verify_work+0x12/0x30 net/ipv6/addrconf.c:4686 4 locks held by udevd/13361: #0: ffff88814194be08 (&p->lock){+.+.}-{3:3}, at: seq_read_iter+0xda/0x1280 fs/seq_file.c:182 #1: ffff88811b3f7088 (&of->mutex){+.+.}-{3:3}, at: kernfs_seq_start+0x4d/0x230 fs/kernfs/file.c:154 #2: ffff8881352daca0 (kn->active#31){.+.+}-{0:0}, at: kernfs_seq_start+0x71/0x230 fs/kernfs/file.c:155 #3: ffff88813b026190 (&dev->mutex){....}-{3:3}, at: device_lock_interruptible include/linux/device.h:995 [inline] #3: ffff88813b026190 (&dev->mutex){....}-{3:3}, at: serial_show+0x26/0xa0 drivers/usb/core/sysfs.c:143 3 locks held by kworker/1:2/16194: #0: ffff888100088938 ((wq_completion)events){+.+.}-{0:0}, at: process_one_work+0x789/0x15d0 kernel/workqueue.c:2608 #1: ffffc900026dfd80 ((work_completion)(&fw_work->work)){+.+.}-{0:0}, at: process_one_work+0x7eb/0x15d0 kernel/workqueue.c:2609 #2: ffffffff88fd2768 (rtnl_mutex){+.+.}-{3:3}, at: register_netdev+0x13/0x50 net/core/dev.c:10391 ============================================= NMI backtrace for cpu 0 CPU: 0 PID: 29 Comm: khungtaskd Not tainted 6.8.0-rc6-syzkaller-00189-gd99e42ce6b83 #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 02/29/2024 Call Trace: __dump_stack lib/dump_stack.c:88 [inline] dump_stack_lvl+0xd9/0x1b0 lib/dump_stack.c:106 nmi_cpu_backtrace+0x277/0x390 lib/nmi_backtrace.c:113 nmi_trigger_cpumask_backtrace+0x299/0x300 lib/nmi_backtrace.c:62 trigger_all_cpu_backtrace include/linux/nmi.h:160 [inline] check_hung_uninterruptible_tasks kernel/hung_task.c:222 [inline] watchdog+0xf87/0x1210 kernel/hung_task.c:379 kthread+0x2c6/0x3a0 kernel/kthread.c:388 ret_from_fork+0x45/0x80 arch/x86/kernel/process.c:147 ret_from_fork_asm+0x11/0x20 arch/x86/entry/entry_64.S:243 Sending NMI from CPU 0 to CPUs 1: NMI backtrace for cpu 1 skipped: idling at native_safe_halt arch/x86/include/asm/irqflags.h:48 [inline] NMI backtrace for cpu 1 skipped: idling at arch_safe_halt arch/x86/include/asm/irqflags.h:86 [inline] NMI backtrace for cpu 1 skipped: idling at acpi_safe_halt+0x1b/0x20 drivers/acpi/processor_idle.c:112