INFO: task kworker/0:4:5698 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/0:4 state:D stack:20496 pid:5698 tgid:5698 ppid:2 task_flags:0x4288060 flags:0x00080000 Workqueue: usb_hub_wq hub_event Call Trace: context_switch kernel/sched/core.c:5388 [inline] __schedule+0x1821/0x5740 kernel/sched/core.c:7189 __schedule_loop kernel/sched/core.c:7268 [inline] schedule+0x164/0x360 kernel/sched/core.c:7283 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:1813 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:621 [inline] __device_release_driver drivers/base/dd.c:1352 [inline] device_release_driver_internal+0x4d9/0x870 drivers/base/dd.c:1375 bus_remove_device+0x455/0x570 drivers/base/bus.c:657 device_del+0x527/0x8f0 drivers/base/core.c:3895 usb_disable_device+0x3d4/0x8d0 drivers/usb/core/message.c:1478 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:3314 [inline] process_scheduled_works+0xb5d/0x1860 kernel/workqueue.c:3397 worker_thread+0xa53/0xfc0 kernel/workqueue.c:3478 kthread+0x389/0x470 kernel/kthread.c:436 ret_from_fork+0x514/0xb70 arch/x86/kernel/process.c:158 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: ffffffff8e95cde0 (rcu_read_lock){....}-{1:3}, at: rcu_lock_acquire include/linux/rcupdate.h:300 [inline] #0: ffffffff8e95cde0 (rcu_read_lock){....}-{1:3}, at: rcu_read_lock include/linux/rcupdate.h:838 [inline] #0: ffffffff8e95cde0 (rcu_read_lock){....}-{1:3}, at: debug_show_all_locks+0x2e/0x180 kernel/locking/lockdep.c:6775 2 locks held by getty/5386: #0: ffff888036d390a0 (&tty->ldisc_sem){++++}-{0:0}, at: tty_ldisc_ref_wait+0x25/0x70 drivers/tty/tty_ldisc.c:243 #1: ffffc900032332e8 (&ldata->atomic_read_lock){+.+.}-{4:4}, at: n_tty_read+0x45c/0x13a0 drivers/tty/n_tty.c:2211 5 locks held by kworker/0:4/5698: #0: ffff88801eaeb540 ((wq_completion)usb_hub_wq){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:3289 [inline] #0: ffff88801eaeb540 ((wq_completion)usb_hub_wq){+.+.}-{0:0}, at: process_scheduled_works+0xa35/0x1860 kernel/workqueue.c:3397 #1: ffffc900041afc40 ((work_completion)(&hub->events)){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:3290 [inline] #1: ffffc900041afc40 ((work_completion)(&hub->events)){+.+.}-{0:0}, at: process_scheduled_works+0xa70/0x1860 kernel/workqueue.c:3397 #2: ffff88802a7971d8 (&dev->mutex){....}-{4:4}, at: device_lock include/linux/device.h:1040 [inline] #2: ffff88802a7971d8 (&dev->mutex){....}-{4:4}, at: hub_event+0x17f/0x4f30 drivers/usb/core/hub.c:5899 #3: ffff88807b2cb1d8 (&dev->mutex){....}-{4:4}, at: device_lock include/linux/device.h:1040 [inline] #3: ffff88807b2cb1d8 (&dev->mutex){....}-{4:4}, at: usb_disconnect+0xf8/0x990 drivers/usb/core/hub.c:2336 #4: ffff88807ab141a0 (&dev->mutex){....}-{4:4}, at: device_lock include/linux/device.h:1040 [inline] #4: ffff88807ab141a0 (&dev->mutex){....}-{4:4}, at: __device_driver_lock drivers/base/dd.c:1174 [inline] #4: ffff88807ab141a0 (&dev->mutex){....}-{4:4}, at: device_release_driver_internal+0xb6/0x870 drivers/base/dd.c:1372 5 locks held by kworker/0:7/5727: #0: ffff88801eaeb540 ((wq_completion)usb_hub_wq){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:3289 [inline] #0: ffff88801eaeb540 ((wq_completion)usb_hub_wq){+.+.}-{0:0}, at: process_scheduled_works+0xa35/0x1860 kernel/workqueue.c:3397 #1: ffffc9000437fc40 ((work_completion)(&hub->events)){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:3290 [inline] #1: ffffc9000437fc40 ((work_completion)(&hub->events)){+.+.}-{0:0}, at: process_scheduled_works+0xa70/0x1860 kernel/workqueue.c:3397 #2: ffff88802a6801d8 (&dev->mutex){....}-{4:4}, at: device_lock include/linux/device.h:1040 [inline] #2: ffff88802a6801d8 (&dev->mutex){....}-{4:4}, at: hub_event+0x17f/0x4f30 drivers/usb/core/hub.c:5899 #3: ffffffff8e9b9118 (kcov_remote_lock){..-.}-{3:3}, at: spin_lock include/linux/spinlock.h:342 [inline] #3: ffffffff8e9b9118 (kcov_remote_lock){..-.}-{3:3}, at: kcov_remote_stop+0x3b6/0x6b0 kernel/kcov.c:1073 #4: ffff88801aea3018 (&pool->lock){-.-.}-{2:2}, at: __queue_work+0x7f7/0x1040 kernel/workqueue.c:-1 1 lock held by syz.1.1119/10499: #0: ffffffff8e962fb8 (rcu_state.barrier_mutex){+.+.}-{4:4}, at: rcu_barrier+0x4c/0x580 kernel/rcu/tree.c:3828 ============================================= NMI backtrace for cpu 0 CPU: 0 UID: 0 PID: 30 Comm: khungtaskd Tainted: G L syzkaller #0 PREEMPT(full) Tainted: [L]=SOFTLOCKUP Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 04/18/2026 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:162 [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:353 [inline] watchdog+0xfd3/0x1030 kernel/hung_task.c:561 kthread+0x389/0x470 kernel/kthread.c:436 ret_from_fork+0x514/0xb70 arch/x86/kernel/process.c:158 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: 5615 Comm: syz-executor Tainted: G L syzkaller #0 PREEMPT(full) Tainted: [L]=SOFTLOCKUP Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 04/18/2026 RIP: 0010:__cpu_to_node+0x22/0xe0 arch/x86/mm/numa.c:343 Code: 90 90 90 90 90 90 90 90 f3 0f 1e fa 41 57 41 56 53 89 fb 49 bf 00 00 00 00 00 fc ff df e8 46 84 4b 00 48 83 3d 7e ed 9d 0e 00 <75> 62 4c 63 f3 bf 08 00 00 00 89 de e8 6d 88 4b 00 83 fb 07 0f 87 RSP: 0018:ffffc90003a0f818 EFLAGS: 00000046 RAX: ffffffff817a401a RBX: 0000000000000001 RCX: ffff888011dfdc40 RDX: 0000000000000000 RSI: ffff888011dfdcc0 RDI: 0000000000000001 RBP: 0000000000000000 R08: ffff888011dfdddc R09: 1ffffffff20618de R10: dffffc0000000000 R11: fffffbfff20618df R12: dffffc0000000000 R13: ffff8880b873af00 R14: ffff888011dfdc54 R15: dffffc0000000000 FS: 000055555fec2540(0000) GS:ffff88812538a000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 0000200000404030 CR3: 0000000074cc8000 CR4: 00000000003526f0 Call Trace: task_node include/linux/sched/topology.h:256 [inline] account_numa_dequeue kernel/sched/fair.c:1779 [inline] account_entity_dequeue kernel/sched/fair.c:3893 [inline] dequeue_entity kernel/sched/fair.c:5703 [inline] dequeue_entities+0x99a/0x3b20 kernel/sched/fair.c:7346 dequeue_task_fair+0x200/0x660 kernel/sched/fair.c:7442 block_task kernel/sched/core.c:2228 [inline] try_to_block_task kernel/sched/core.c:6625 [inline] __schedule+0x6de/0x5740 kernel/sched/core.c:7098 __schedule_loop kernel/sched/core.c:7268 [inline] schedule+0x164/0x360 kernel/sched/core.c:7283 do_nanosleep+0x1c2/0x620 kernel/time/hrtimer.c:2293 hrtimer_nanosleep+0x18f/0x3a0 kernel/time/hrtimer.c:2339 __do_sys_clock_nanosleep kernel/time/posix-timers.c:1391 [inline] __se_sys_clock_nanosleep+0x35b/0x3b0 kernel/time/posix-timers.c:1368 do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline] do_syscall_64+0x15f/0xf80 arch/x86/entry/syscall_64.c:94 entry_SYSCALL_64_after_hwframe+0x77/0x7f RIP: 0033:0x7f9de2357fd7 Code: 48 89 fa 4c 89 df e8 a8 56 00 00 8b 93 08 03 00 00 59 5e 48 83 f8 fc 74 1a 5b c3 0f 1f 84 00 00 00 00 00 48 8b 44 24 10 0f 05 <5b> c3 0f 1f 80 00 00 00 00 83 e2 39 83 fa 08 75 de e8 23 ff ff ff RSP: 002b:00007ffd1d8982b0 EFLAGS: 00000202 ORIG_RAX: 00000000000000e6 RAX: ffffffffffffffda RBX: 000055555fec2540 RCX: 00007f9de2357fd7 RDX: 00007ffd1d8982f0 RSI: 0000000000000000 RDI: 0000000000000000 RBP: 00007ffd1d8987d0 R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000202 R12: 0000000000000004 R13: 00007ffd1d89832c R14: 00007ffd1d8983c0 R15: 0000000000000000