INFO: task kworker/0:10:2000 blocked for more than 143 seconds. Not tainted syzkaller #0 "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message. task:kworker/0:10 state:D stack:23656 pid:2000 tgid:2000 ppid:2 task_flags:0x4288060 flags:0x00004000 Workqueue: usb_hub_wq hub_event Call Trace: 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 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] , at: rcu_read_lock include/linux/rcupdate.h:841 [inline] , at: debug_show_all_locks+0x36/0x1c0 kernel/locking/lockdep.c:6775 1 lock held by dhcpcd/2885: 2 locks held by getty/2908: #0: ffff88811232c0a0 (&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/0:4/5245: #0: ffff8881066f7948 ((wq_completion)usb_hub_wq){+.+.}-{0:0}, at: process_one_work+0x12a2/0x1b70 kernel/workqueue.c:3211 #1: ffffc9000235fd10 ((work_completion)(&hub->events)){+.+.}-{0:0} , at: process_one_work+0x929/0x1b70 kernel/workqueue.c:3212 #2: ffff88810bf70198 (&dev->mutex){....}-{4:4}, at: device_lock include/linux/device.h:911 [inline] #2: ffff88810bf70198 (&dev->mutex){....}-{4:4}, at: hub_event+0x1be/0x5060 drivers/usb/core/hub.c:5898 #3: ffff888134bee198 (&dev->mutex){....}-{4:4} , at: device_lock include/linux/device.h:911 [inline] , at: __device_attach+0x7e/0x4b0 drivers/base/dd.c:1006 #4: ffff88814e34f160 (&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 6 locks held by kworker/0:3/8609: #0: ffff8881066f7948 ((wq_completion)usb_hub_wq){+.+.}-{0:0}, at: process_one_work+0x12a2/0x1b70 kernel/workqueue.c:3211 #1: ffffc900145afd10 ((work_completion)(&hub->events)){+.+.}-{0:0}, at: process_one_work+0x929/0x1b70 kernel/workqueue.c:3212 #2: ffff88810b3dc198 (&dev->mutex){....}-{4:4}, at: device_lock include/linux/device.h:911 [inline] ffff88810b3dc198 (&dev->mutex){....}-{4:4}, at: hub_event+0x1be/0x5060 drivers/usb/core/hub.c:5898 #3: ffff888118a02198 (&dev->mutex){....}-{4:4}, at: device_lock include/linux/device.h:911 [inline] #3: ffff888118a02198 (&dev->mutex){....}-{4:4}, at: __device_attach+0x7e/0x4b0 drivers/base/dd.c:1006 #4: ffff888133638160 (&dev->mutex){....}-{4:4}, at: device_lock include/linux/device.h:911 [inline] #4: ffff888133638160 (&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 kworker/u8:1/12327: #0: ffff888111af2148 ((wq_completion)ipv6_addrconf){+.+.}-{0:0} , at: process_one_work+0x12a2/0x1b70 kernel/workqueue.c:3211 #1: ffffc900121b7d10 ((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] #2: ffffffff8a5fa288 (rtnl_mutex){+.+.}-{4:4}, at: addrconf_verify_work+0x12/0x30 net/ipv6/addrconf.c:4734 3 locks held by kworker/1:1/16589: 5 locks held by kworker/1:9/19891: #0: ffff8881066f7948 ((wq_completion)usb_hub_wq){+.+.}-{0:0}, at: process_one_work+0x12a2/0x1b70 kernel/workqueue.c:3211 #1: ffffc90001fbfd10 ((work_completion)(&hub->events) ){+.+.}-{0:0}, at: process_one_work+0x929/0x1b70 kernel/workqueue.c:3212 #2: ffff88810bf20198 (&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: ffff88811c098198 (&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 #4: ffff8881366d0160 (&dev->mutex){....}-{4:4}, at: device_lock include/linux/device.h:911 [inline] ffff8881366d0160 (&dev->mutex){....}-{4:4}, at: __device_attach+0x7e/0x4b0 drivers/base/dd.c:1006 6 locks held by kworker/1:3/22695: #0: ffff8881066f7948 ((wq_completion)usb_hub_wq){+.+.}-{0:0}, at: process_one_work+0x12a2/0x1b70 kernel/workqueue.c:3211 #1: ffffc90006f27d10 ((work_completion)(&hub->events)){+.+.}-{0:0}, at: process_one_work+0x929/0x1b70 kernel/workqueue.c:3212 #2: ffff88810bf00198 (&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: ffff888125030198 (&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: ffff888114f45160 (&dev->mutex){....}-{4:4}, at: device_lock include/linux/device.h:911 [inline] #4: ffff888114f45160 (&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 4 locks held by udevd/27353: #0: ffff88812a85f668 (&p->lock ){+.+.}-{4:4}, at: seq_read_iter+0xe1/0x12c0 fs/seq_file.c:182 #1: ffff888136767888 (&of->mutex #2){+.+.}-{4:4}, at: kernfs_seq_start+0x4d/0x240 fs/kernfs/file.c:154 #2: ffff88811c414878 (kn->active#12 ){++++}-{0:0}, at: kernfs_seq_start+0x71/0x240 fs/kernfs/file.c:155 #3: ffff888118a02198 (&dev->mutex){....}-{4:4}, at: device_lock_interruptible include/linux/device.h:916 [inline] #3: ffff888118a02198 (&dev->mutex){....}-{4:4}, at: serial_show+0x26/0xa0 drivers/usb/core/sysfs.c:143 4 locks held by udevd/27737: #0: ffff88813010e9e0 (&p->lock){+.+.}-{4:4}, at: seq_read_iter+0xe1/0x12c0 fs/seq_file.c:182 #1: ffff888138a64888 (&of->mutex #2){+.+.}-{4:4}, at: kernfs_seq_start+0x4d/0x240 fs/kernfs/file.c:154 #2: ffff888137706008 (kn->active#9){++++}-{0:0} , at: kernfs_seq_start+0x71/0x240 fs/kernfs/file.c:155 #3: ffff888125030198 (&dev->mutex){....}-{4:4} , at: device_lock_interruptible include/linux/device.h:916 [inline] , at: manufacturer_show+0x26/0xa0 drivers/usb/core/sysfs.c:142 4 locks held by udevd/27742: #0: ffff88813c3dbd58 (&p->lock ){+.+.}-{4:4}, at: seq_read_iter+0xe1/0x12c0 fs/seq_file.c:182 #1: ffff8881247a6c88 (&of->mutex#2 ){+.+.}-{4:4} , at: kernfs_seq_start+0x4d/0x240 fs/kernfs/file.c:154 #2: ffff88812755d788 (kn->active#9){++++}-{0:0} , at: kernfs_seq_start+0x71/0x240 fs/kernfs/file.c:155 #3: ffff888134bee198 (&dev->mutex ){....}-{4:4} , at: device_lock_interruptible include/linux/device.h:916 [inline] , at: manufacturer_show+0x26/0xa0 drivers/usb/core/sysfs.c:142 4 locks held by kworker/1:4/31952: 6 locks held by kworker/0:10/2000: #0: ffff8881066f7948 ((wq_completion)usb_hub_wq){+.+.}-{0:0}, at: process_one_work+0x12a2/0x1b70 kernel/workqueue.c:3211 #1: ffffc9000d62fd10 ( (work_completion)(&hub->events)){+.+.}-{0:0}, at: process_one_work+0x929/0x1b70 kernel/workqueue.c:3212 #2: ffff88810bf88198 (&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: ffff888117231198 (&dev->mutex){....}-{4:4}, at: device_lock include/linux/device.h:911 [inline] #3: ffff888117231198 (&dev->mutex){....}-{4:4}, at: usb_disconnect+0x10a/0x9c0 drivers/usb/core/hub.c:2335 #4: ffff888134bea160 (&dev->mutex){....}-{4:4}, at: device_lock include/linux/device.h:911 [inline] #4: ffff888134bea160 (&dev->mutex){....}-{4:4}, at: __device_driver_lock drivers/base/dd.c:1096 [inline] #4: ffff888134bea160 (&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 2 locks held by syz.7.6760/4134: ============================================= 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: __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 Sending NMI from CPU 0 to CPUs 1: NMI backtrace for cpu 1 CPU: 1 UID: 0 PID: 16589 Comm: kworker/1:1 Not tainted syzkaller #0 PREEMPT(voluntary) Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 07/12/2025 Workqueue: events dvb_usb_read_remote_control RIP: 0010:sprintf+0x7c/0x100 lib/vsprintf.c:3084 Code: b3 8a b5 41 48 c7 44 24 08 61 2b dc 88 48 c7 44 24 10 c0 58 3b 87 c7 03 f1 f1 f1 f1 c7 43 04 00 00 00 f3 c7 43 08 f3 f3 f3 f3 <65> 48 8b 05 c4 16 57 05 48 89 44 24 78 31 c0 e8 00 9f 42 fa 48 8d RSP: 0018:ffffc90015787490 EFLAGS: 00000282 RAX: dffffc0000000000 RBX: fffff52002af0e92 RCX: 000000000004c372 RDX: 0000000000000d62 RSI: ffffffff87692a60 RDI: ffffc90015787678 RBP: ffffc90015787558 R08: 0000000000000001 R09: 0000000000000000 R10: 0000000000000001 R11: 00000000011dec28 R12: ffffc90015787678 R13: ffffffff87692a60 R14: 0000000000000000 R15: ffffc90015787678 FS: 0000000000000000(0000) GS:ffff888268ff9000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 00005555666774a8 CR3: 0000000148234000 CR4: 00000000003506f0 Call Trace: print_time kernel/printk/printk.c:1381 [inline] info_print_prefix+0x25a/0x350 kernel/printk/printk.c:1407 record_print_text+0x140/0x400 kernel/printk/printk.c:1456 printk_get_next_message+0x2d1/0x6d0 kernel/printk/printk.c:3024 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_core_query+0x2d7/0x500 drivers/media/usb/dvb-usb/m920x.c:229 dvb_usb_read_remote_control+0xdd/0x1c0 drivers/media/usb/dvb-usb/dvb-usb-remote.c:261 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