INFO: task kworker/0:3:1221 blocked for more than 143 seconds. Tainted: G L syzkaller #0 "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message. task:kworker/0:3 state:D stack:19416 pid:1221 tgid:1221 ppid:2 task_flags:0x4288060 flags:0x00080000 Workqueue: usb_hub_wq hub_event Call Trace: context_switch kernel/sched/core.c:5260 [inline] __schedule+0x14ef/0x4fb0 kernel/sched/core.c:6867 __schedule_loop kernel/sched/core.c:6949 [inline] schedule+0x164/0x360 kernel/sched/core.c:6964 schedule_timeout+0xc3/0x2c0 kernel/time/sleep_timeout.c:75 do_wait_for_common kernel/sched/completion.c:100 [inline] __wait_for_common kernel/sched/completion.c:121 [inline] wait_for_common kernel/sched/completion.c:132 [inline] wait_for_completion+0x2cc/0x5e0 kernel/sched/completion.c:153 i2c_del_adapter+0x5c0/0x790 drivers/i2c/i2c-core-base.c:1814 dvb_usb_i2c_exit+0x64/0xb0 drivers/media/usb/dvb-usb/dvb-usb-i2c.c:46 dvb_usb_exit drivers/media/usb/dvb-usb/dvb-usb-init.c:144 [inline] dvb_usb_device_exit+0x1cb/0x360 drivers/media/usb/dvb-usb/dvb-usb-init.c:338 usb_unbind_interface+0x26e/0x910 drivers/usb/core/driver.c:458 device_remove drivers/base/dd.c:571 [inline] __device_release_driver drivers/base/dd.c:1282 [inline] device_release_driver_internal+0x4d9/0x800 drivers/base/dd.c:1305 bus_remove_device+0x34d/0x440 drivers/base/bus.c:616 device_del+0x527/0x8f0 drivers/base/core.c:3878 usb_disable_device+0x3d4/0x8d0 drivers/usb/core/message.c:1418 usb_disconnect+0x32f/0x990 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+0x1cc9/0x4f30 drivers/usb/core/hub.c:5953 process_one_work kernel/workqueue.c:3257 [inline] process_scheduled_works+0xaec/0x17a0 kernel/workqueue.c:3340 worker_thread+0x89f/0xd90 kernel/workqueue.c:3421 kthread+0x726/0x8b0 kernel/kthread.c:463 ret_from_fork+0x51b/0xa40 arch/x86/kernel/process.c:158 ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:246 Showing all locks held in the system: 1 lock held by khungtaskd/31: #0: ffffffff8e35a360 (rcu_read_lock){....}-{1:3}, at: rcu_lock_acquire include/linux/rcupdate.h:331 [inline] #0: ffffffff8e35a360 (rcu_read_lock){....}-{1:3}, at: rcu_read_lock include/linux/rcupdate.h:867 [inline] #0: ffffffff8e35a360 (rcu_read_lock){....}-{1:3}, at: debug_show_all_locks+0x2e/0x180 kernel/locking/lockdep.c:6775 5 locks held by kworker/0:3/1221: #0: ffff8880206d7d48 ((wq_completion)usb_hub_wq){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:3232 [inline] #0: ffff8880206d7d48 ((wq_completion)usb_hub_wq){+.+.}-{0:0}, at: process_scheduled_works+0x9d4/0x17a0 kernel/workqueue.c:3340 #1: ffffc9000411fbc0 ((work_completion)(&hub->events)){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:3233 [inline] #1: ffffc9000411fbc0 ((work_completion)(&hub->events)){+.+.}-{0:0}, at: process_scheduled_works+0xa0f/0x17a0 kernel/workqueue.c:3340 #2: ffff888143f75198 (&dev->mutex){....}-{4:4}, at: device_lock include/linux/device.h:895 [inline] #2: ffff888143f75198 (&dev->mutex){....}-{4:4}, at: hub_event+0x17f/0x4f30 drivers/usb/core/hub.c:5899 #3: ffff888032701198 (&dev->mutex){....}-{4:4}, at: device_lock include/linux/device.h:895 [inline] #3: ffff888032701198 (&dev->mutex){....}-{4:4}, at: usb_disconnect+0xf8/0x990 drivers/usb/core/hub.c:2336 #4: ffff88805575e160 (&dev->mutex){....}-{4:4}, at: device_lock include/linux/device.h:895 [inline] #4: ffff88805575e160 (&dev->mutex){....}-{4:4}, at: __device_driver_lock drivers/base/dd.c:1104 [inline] #4: ffff88805575e160 (&dev->mutex){....}-{4:4}, at: device_release_driver_internal+0xb6/0x800 drivers/base/dd.c:1302 3 locks held by kworker/u8:12/3578: #0: ffff88813fe29948 ((wq_completion)events_unbound#2){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:3232 [inline] #0: ffff88813fe29948 ((wq_completion)events_unbound#2){+.+.}-{0:0}, at: process_scheduled_works+0x9d4/0x17a0 kernel/workqueue.c:3340 #1: ffffc9000c167bc0 ((linkwatch_work).work){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:3233 [inline] #1: ffffc9000c167bc0 ((linkwatch_work).work){+.+.}-{0:0}, at: process_scheduled_works+0xa0f/0x17a0 kernel/workqueue.c:3340 #2: ffffffff8f7a8808 (rtnl_mutex){+.+.}-{4:4}, at: linkwatch_event+0xe/0x60 net/core/link_watch.c:303 2 locks held by kworker/u8:14/4364: #0: ffff88801c365948 ((wq_completion)iou_exit){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:3232 [inline] #0: ffff88801c365948 ((wq_completion)iou_exit){+.+.}-{0:0}, at: process_scheduled_works+0x9d4/0x17a0 kernel/workqueue.c:3340 #1: ffffc9000d3d7bc0 ((work_completion)(&ctx->exit_work)){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:3233 [inline] #1: ffffc9000d3d7bc0 ((work_completion)(&ctx->exit_work)){+.+.}-{0:0}, at: process_scheduled_works+0xa0f/0x17a0 kernel/workqueue.c:3340 2 locks held by getty/5590: #0: ffff8880351f10a0 (&tty->ldisc_sem){++++}-{0:0}, at: tty_ldisc_ref_wait+0x25/0x70 drivers/tty/tty_ldisc.c:243 #1: ffffc9000332b2f0 (&ldata->atomic_read_lock){+.+.}-{4:4}, at: n_tty_read+0x45c/0x13c0 drivers/tty/n_tty.c:2211 4 locks held by udevd/5830: #0: ffff88807616c9e0 (&p->lock){+.+.}-{4:4}, at: seq_read_iter+0xb7/0xe10 fs/seq_file.c:182 #1: ffff888031636088 (&of->mutex#2){+.+.}-{4:4}, at: kernfs_seq_start+0x5c/0x420 fs/kernfs/file.c:172 #2: ffff888050973b48 (kn->active#25){++++}-{0:0}, at: kernfs_get_active_of fs/kernfs/file.c:80 [inline] #2: ffff888050973b48 (kn->active#25){++++}-{0:0}, at: kernfs_seq_start+0xb2/0x420 fs/kernfs/file.c:173 #3: ffff888032701198 (&dev->mutex){....}-{4:4}, at: device_lock_interruptible include/linux/device.h:900 [inline] #3: ffff888032701198 (&dev->mutex){....}-{4:4}, at: manufacturer_show+0x26/0xa0 drivers/usb/core/sysfs.c:142 2 locks held by kworker/u8:15/5976: #0: ffff88801c365948 ((wq_completion)iou_exit){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:3232 [inline] #0: ffff88801c365948 ((wq_completion)iou_exit){+.+.}-{0:0}, at: process_scheduled_works+0x9d4/0x17a0 kernel/workqueue.c:3340 #1: ffffc90004c17bc0 ((work_completion)(&ctx->exit_work)){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:3233 [inline] #1: ffffc90004c17bc0 ((work_completion)(&ctx->exit_work)){+.+.}-{0:0}, at: process_scheduled_works+0xa0f/0x17a0 kernel/workqueue.c:3340 3 locks held by kworker/u8:23/7863: #0: ffff88814cc26948 ((wq_completion)ipv6_addrconf){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:3232 [inline] #0: ffff88814cc26948 ((wq_completion)ipv6_addrconf){+.+.}-{0:0}, at: process_scheduled_works+0x9d4/0x17a0 kernel/workqueue.c:3340 #1: ffffc90003d2fbc0 ((work_completion)(&(&ifa->dad_work)->work)){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:3233 [inline] #1: ffffc90003d2fbc0 ((work_completion)(&(&ifa->dad_work)->work)){+.+.}-{0:0}, at: process_scheduled_works+0xa0f/0x17a0 kernel/workqueue.c:3340 #2: ffffffff8f7a8808 (rtnl_mutex){+.+.}-{4:4}, at: rtnl_net_lock include/linux/rtnetlink.h:130 [inline] #2: ffffffff8f7a8808 (rtnl_mutex){+.+.}-{4:4}, at: addrconf_dad_work+0x11e/0x14c0 net/ipv6/addrconf.c:4194 2 locks held by syz.5.958/9471: 4 locks held by syz.4.959/9477: #0: ffff88802a390160 (&mousedev->mutex/1){+.+.}-{4:4}, at: mixdev_close_devices+0x31/0x210 drivers/input/mousedev.c:486 #1: ffff88802a594160 (&mousedev->mutex#2){+.+.}-{4:4}, at: mousedev_close_device drivers/input/mousedev.c:441 [inline] #1: ffff88802a594160 (&mousedev->mutex#2){+.+.}-{4:4}, at: mixdev_close_devices+0xba/0x210 drivers/input/mousedev.c:494 #2: ffff88802a5932c0 (&dev->mutex#2){+.+.}-{4:4}, at: class_mutex_constructor include/linux/mutex.h:253 [inline] #2: ffff88802a5932c0 (&dev->mutex#2){+.+.}-{4:4}, at: input_close_device+0x4c/0x280 drivers/input/input.c:646 #3: ffffffff8e360c78 (rcu_state.exp_mutex){+.+.}-{4:4}, at: exp_funnel_lock kernel/rcu/tree_exp.h:343 [inline] #3: ffffffff8e360c78 (rcu_state.exp_mutex){+.+.}-{4:4}, at: synchronize_rcu_expedited+0x38d/0x770 kernel/rcu/tree_exp.h:956 1 lock held by syz.1.964/9491: #0: ffffffff8e360b40 (rcu_state.barrier_mutex){+.+.}-{4:4}, at: rcu_barrier+0x4c/0x580 kernel/rcu/tree.c:3816 3 locks held by syz.1.964/9495: #0: ffffffff8f816810 (cb_lock){++++}-{4:4}, at: genl_rcv+0x19/0x40 net/netlink/genetlink.c:1218 #1: ffffffff8f816628 (genl_mutex){+.+.}-{4:4}, at: genl_lock net/netlink/genetlink.c:35 [inline] #1: ffffffff8f816628 (genl_mutex){+.+.}-{4:4}, at: genl_op_lock net/netlink/genetlink.c:60 [inline] #1: ffffffff8f816628 (genl_mutex){+.+.}-{4:4}, at: genl_rcv_msg+0x10b/0x7a0 net/netlink/genetlink.c:1209 #2: ffffffff8f7a8808 (rtnl_mutex){+.+.}-{4:4}, at: tipc_nl_bearer_enable+0x17/0x40 net/tipc/bearer.c:1055 2 locks held by syz.1.964/9498: #0: ffffffff8f816810 (cb_lock){++++}-{4:4}, at: genl_rcv+0x19/0x40 net/netlink/genetlink.c:1218 #1: ffffffff8f816628 (genl_mutex){+.+.}-{4:4}, at: genl_lock net/netlink/genetlink.c:35 [inline] #1: ffffffff8f816628 (genl_mutex){+.+.}-{4:4}, at: genl_op_lock net/netlink/genetlink.c:60 [inline] #1: ffffffff8f816628 (genl_mutex){+.+.}-{4:4}, at: genl_rcv_msg+0x10b/0x7a0 net/netlink/genetlink.c:1209 2 locks held by syz.1.964/9499: #0: ffffffff8f816810 (cb_lock){++++}-{4:4}, at: genl_rcv+0x19/0x40 net/netlink/genetlink.c:1218 #1: ffffffff8f816628 (genl_mutex){+.+.}-{4:4}, at: genl_lock net/netlink/genetlink.c:35 [inline] #1: ffffffff8f816628 (genl_mutex){+.+.}-{4:4}, at: genl_op_lock net/netlink/genetlink.c:60 [inline] #1: ffffffff8f816628 (genl_mutex){+.+.}-{4:4}, at: genl_rcv_msg+0x10b/0x7a0 net/netlink/genetlink.c:1209 2 locks held by syz.1.964/9500: #0: ffffffff8f816810 (cb_lock){++++}-{4:4}, at: genl_rcv+0x19/0x40 net/netlink/genetlink.c:1218 #1: ffffffff8f816628 (genl_mutex){+.+.}-{4:4}, at: genl_lock net/netlink/genetlink.c:35 [inline] #1: ffffffff8f816628 (genl_mutex){+.+.}-{4:4}, at: genl_op_lock net/netlink/genetlink.c:60 [inline] #1: ffffffff8f816628 (genl_mutex){+.+.}-{4:4}, at: genl_rcv_msg+0x10b/0x7a0 net/netlink/genetlink.c:1209 2 locks held by syz.2.966/9496: #0: ffffffff8f7a8808 (rtnl_mutex){+.+.}-{4:4}, at: tun_detach drivers/net/tun.c:634 [inline] #0: ffffffff8f7a8808 (rtnl_mutex){+.+.}-{4:4}, at: tun_chr_close+0x3e/0x1c0 drivers/net/tun.c:3436 #1: ffffffff8e360c78 (rcu_state.exp_mutex){+.+.}-{4:4}, at: exp_funnel_lock kernel/rcu/tree_exp.h:311 [inline] #1: ffffffff8e360c78 (rcu_state.exp_mutex){+.+.}-{4:4}, at: synchronize_rcu_expedited+0x2d0/0x770 kernel/rcu/tree_exp.h:956 ============================================= NMI backtrace for cpu 0 CPU: 0 UID: 0 PID: 31 Comm: khungtaskd Tainted: G L syzkaller #0 PREEMPT(full) Tainted: [L]=SOFTLOCKUP Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/13/2026 Call Trace: dump_stack_lvl+0xe8/0x150 lib/dump_stack.c:120 nmi_cpu_backtrace+0x274/0x2d0 lib/nmi_backtrace.c:113 nmi_trigger_cpumask_backtrace+0x17a/0x300 lib/nmi_backtrace.c:62 trigger_all_cpu_backtrace include/linux/nmi.h:161 [inline] __sys_info lib/sys_info.c:157 [inline] sys_info+0x135/0x170 lib/sys_info.c:165 check_hung_uninterruptible_tasks kernel/hung_task.c:346 [inline] watchdog+0xf90/0xfe0 kernel/hung_task.c:515 kthread+0x726/0x8b0 kernel/kthread.c:463 ret_from_fork+0x51b/0xa40 arch/x86/kernel/process.c:158 ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:246 Sending NMI from CPU 0 to CPUs 1: NMI backtrace for cpu 1 CPU: 1 UID: 0 PID: 0 Comm: swapper/1 Tainted: G L syzkaller #0 PREEMPT(full) Tainted: [L]=SOFTLOCKUP Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/13/2026 RIP: 0010:pv_native_safe_halt+0xf/0x20 arch/x86/kernel/paravirt.c:82 Code: 28 5f 02 e9 d3 e5 02 00 cc cc cc 90 90 90 90 90 90 90 90 90 90 90 90 90 90 90 90 f3 0f 1e fa 66 90 0f 00 2d d3 b7 10 00 fb f4 cc cc cc cc cc cc cc cc cc cc cc cc cc cc cc cc 90 90 90 90 90 RSP: 0018:ffffc90000197e20 EFLAGS: 00000246 RAX: 00000000002e8771 RBX: ffffffff819849ed RCX: 0000000080000001 RDX: 0000000000000001 RSI: ffffffff8dacfb11 RDI: ffffffff8be73880 RBP: ffffc90000197f10 R08: ffff8880b87336db R09: 1ffff110170e66db R10: dffffc0000000000 R11: ffffed10170e66dc R12: ffffffff8fced970 R13: 1ffff110039d8b70 R14: 0000000000000001 R15: 0000000000000001 FS: 0000000000000000(0000) GS:ffff888125a28000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 0000562e2fff2300 CR3: 000000007a602000 CR4: 00000000003526f0 DR0: 0000000000000002 DR1: 0000000000000007 DR2: 0000000000000004 DR3: 0000000000000001 DR6: 00000000ffff0ff0 DR7: 0000000000000400 Call Trace: arch_safe_halt arch/x86/kernel/process.c:766 [inline] default_idle+0x9/0x20 arch/x86/kernel/process.c:767 default_idle_call+0x72/0xb0 kernel/sched/idle.c:122 cpuidle_idle_call kernel/sched/idle.c:191 [inline] do_idle+0x1bd/0x500 kernel/sched/idle.c:332 cpu_startup_entry+0x43/0x60 kernel/sched/idle.c:430 start_secondary+0x101/0x110 arch/x86/kernel/smpboot.c:312 common_startup_64+0x13e/0x147