INFO: task kworker/1:0:16121 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/1:0 state:D stack:21408 pid:16121 tgid:16121 ppid:2 task_flags:0x4208060 flags:0x00080000 Workqueue: usb_hub_wq hub_event Call Trace: context_switch kernel/sched/core.c:5256 [inline] __schedule+0x14bc/0x5000 kernel/sched/core.c:6863 __schedule_loop kernel/sched/core.c:6945 [inline] schedule+0x165/0x360 kernel/sched/core.c:6960 schedule_timeout+0x9a/0x270 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+0x2bf/0x5d0 kernel/sched/completion.c:153 i2c_del_adapter+0x591/0x760 drivers/i2c/i2c-core-base.c:1814 dvb_usbv2_probe+0x497/0x3c20 drivers/media/usb/dvb-usb-v2/dvb_usb_core.c:993 usb_probe_interface+0x668/0xc90 drivers/usb/core/driver.c:396 call_driver_probe drivers/base/dd.c:-1 [inline] really_probe+0x26d/0xad0 drivers/base/dd.c:659 __driver_probe_device+0x18c/0x320 drivers/base/dd.c:801 driver_probe_device+0x4f/0x240 drivers/base/dd.c:831 __device_attach_driver+0x279/0x430 drivers/base/dd.c:959 bus_for_each_drv+0x251/0x2e0 drivers/base/bus.c:500 __device_attach+0x2b8/0x430 drivers/base/dd.c:1031 device_initial_probe+0xa1/0xd0 drivers/base/dd.c:1086 bus_probe_device+0x12a/0x220 drivers/base/bus.c:574 device_add+0x7b6/0xb80 drivers/base/core.c:3689 usb_set_configuration+0x1a87/0x2110 drivers/usb/core/message.c:2210 usb_generic_driver_probe+0x8d/0x150 drivers/usb/core/generic.c:250 usb_probe_device+0x1c4/0x3c0 drivers/usb/core/driver.c:291 call_driver_probe drivers/base/dd.c:-1 [inline] really_probe+0x26d/0xad0 drivers/base/dd.c:659 __driver_probe_device+0x18c/0x320 drivers/base/dd.c:801 driver_probe_device+0x4f/0x240 drivers/base/dd.c:831 __device_attach_driver+0x279/0x430 drivers/base/dd.c:959 bus_for_each_drv+0x251/0x2e0 drivers/base/bus.c:500 __device_attach+0x2b8/0x430 drivers/base/dd.c:1031 device_initial_probe+0xa1/0xd0 drivers/base/dd.c:1086 bus_probe_device+0x12a/0x220 drivers/base/bus.c:574 device_add+0x7b6/0xb80 drivers/base/core.c:3689 usb_new_device+0xa39/0x1720 drivers/usb/core/hub.c:2695 hub_port_connect drivers/usb/core/hub.c:5567 [inline] hub_port_connect_change drivers/usb/core/hub.c:5707 [inline] port_event drivers/usb/core/hub.c:5871 [inline] hub_event+0x29b1/0x4ef0 drivers/usb/core/hub.c:5953 process_one_work kernel/workqueue.c:3257 [inline] process_scheduled_works+0xad1/0x1770 kernel/workqueue.c:3340 worker_thread+0x8a0/0xda0 kernel/workqueue.c:3421 kthread+0x711/0x8a0 kernel/kthread.c:463 ret_from_fork+0x599/0xb30 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: ffffffff8df419e0 (rcu_read_lock){....}-{1:3}, at: rcu_lock_acquire include/linux/rcupdate.h:331 [inline] #0: ffffffff8df419e0 (rcu_read_lock){....}-{1:3}, at: rcu_read_lock include/linux/rcupdate.h:867 [inline] #0: ffffffff8df419e0 (rcu_read_lock){....}-{1:3}, at: debug_show_all_locks+0x2e/0x180 kernel/locking/lockdep.c:6775 1 lock held by syslogd/5183: #0: ffff8880b863a918 (&rq->__lock){-.-.}-{2:2}, at: raw_spin_rq_lock_nested+0xad/0x140 kernel/sched/core.c:647 2 locks held by getty/5592: #0: ffff88814d6b90a0 (&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+0x449/0x1460 drivers/tty/n_tty.c:2211 5 locks held by kworker/1:0/16121: #0: ffff88801aeb6148 ((wq_completion)usb_hub_wq){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:3232 [inline] #0: ffff88801aeb6148 ((wq_completion)usb_hub_wq){+.+.}-{0:0}, at: process_scheduled_works+0x9b4/0x1770 kernel/workqueue.c:3340 #1: ffffc9000bad7b80 ((work_completion)(&hub->events)){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:3233 [inline] #1: ffffc9000bad7b80 ((work_completion)(&hub->events)){+.+.}-{0:0}, at: process_scheduled_works+0x9ef/0x1770 kernel/workqueue.c:3340 #2: ffff8881447c9198 (&dev->mutex){....}-{4:4}, at: device_lock include/linux/device.h:895 [inline] #2: ffff8881447c9198 (&dev->mutex){....}-{4:4}, at: hub_event+0x187/0x4ef0 drivers/usb/core/hub.c:5899 #3: ffff8880644fc198 (&dev->mutex){....}-{4:4}, at: device_lock include/linux/device.h:895 [inline] #3: ffff8880644fc198 (&dev->mutex){....}-{4:4}, at: __device_attach+0x88/0x430 drivers/base/dd.c:1006 #4: ffff888033346160 (&dev->mutex){....}-{4:4}, at: device_lock include/linux/device.h:895 [inline] #4: ffff888033346160 (&dev->mutex){....}-{4:4}, at: __device_attach+0x88/0x430 drivers/base/dd.c:1006 4 locks held by udevd/6693: #0: ffff888048a410a0 (&p->lock){+.+.}-{4:4}, at: seq_read_iter+0xb7/0xe20 fs/seq_file.c:182 #1: ffff888056ee6c88 (&of->mutex#2){+.+.}-{4:4}, at: kernfs_seq_start+0x5c/0x420 fs/kernfs/file.c:172 #2: ffff888065d52b48 (kn->active#29){++++}-{0:0}, at: kernfs_get_active_of fs/kernfs/file.c:80 [inline] #2: ffff888065d52b48 (kn->active#29){++++}-{0:0}, at: kernfs_seq_start+0xb2/0x420 fs/kernfs/file.c:173 #3: ffff8880644fc198 (&dev->mutex){....}-{4:4}, at: device_lock_interruptible include/linux/device.h:900 [inline] #3: ffff8880644fc198 (&dev->mutex){....}-{4:4}, at: manufacturer_show+0x26/0xa0 drivers/usb/core/sysfs.c:142 ============================================= NMI backtrace for cpu 1 CPU: 1 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 10/25/2025 Call Trace: dump_stack_lvl+0x189/0x250 lib/dump_stack.c:120 nmi_cpu_backtrace+0x39e/0x3d0 lib/nmi_backtrace.c:113 nmi_trigger_cpumask_backtrace+0x17a/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+0x135/0x170 lib/sys_info.c:165 check_hung_uninterruptible_tasks kernel/hung_task.c:346 [inline] watchdog+0xf95/0xfe0 kernel/hung_task.c:515 kthread+0x711/0x8a0 kernel/kthread.c:463 ret_from_fork+0x599/0xb30 arch/x86/kernel/process.c:158 ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:246 Sending NMI from CPU 1 to CPUs 0: NMI backtrace for cpu 0 CPU: 0 UID: 0 PID: 5909 Comm: kworker/0:4 Tainted: G L syzkaller #0 PREEMPT(full) Tainted: [L]=SOFTLOCKUP Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 10/25/2025 Workqueue: events dvb_usb_read_remote_control RIP: 0010:io_serial_in+0x77/0xc0 drivers/tty/serial/8250/8250_port.c:400 Code: e8 1e 98 a6 fc 44 89 f9 d3 e3 49 83 c6 40 4c 89 f0 48 c1 e8 03 42 80 3c 20 00 74 08 4c 89 f7 e8 cf ee 0c fd 41 03 1e 89 da ec <0f> b6 c0 5b 41 5c 41 5e 41 5f e9 8a 22 43 06 cc 44 89 f9 80 e1 07 RSP: 0018:ffffc900042ff190 EFLAGS: 00000002 RAX: 1ffffffff337de00 RBX: 00000000000003fd RCX: 0000000000000000 RDX: 00000000000003fd RSI: 0000000000000000 RDI: 0000000000000020 RBP: ffffffff99bef510 R08: ffff8881482a0237 R09: 1ffff11029054046 R10: dffffc0000000000 R11: ffffffff851b1890 R12: dffffc0000000000 R13: 0000000000000000 R14: ffffffff99bef280 R15: 0000000000000000 FS: 0000000000000000(0000) GS:ffff888125e3a000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 00000000f74099b4 CR3: 0000000075eac000 CR4: 00000000003526f0 DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000 DR3: 0000000000000600 DR6: 00000000ffff0ff0 DR7: 0000000000000400 Call Trace: serial_in drivers/tty/serial/8250/8250.h:128 [inline] serial_lsr_in drivers/tty/serial/8250/8250.h:150 [inline] wait_for_lsr+0x1a1/0x2f0 drivers/tty/serial/8250/8250_port.c:1961 fifo_wait_for_lsr drivers/tty/serial/8250/8250_port.c:3234 [inline] serial8250_console_fifo_write drivers/tty/serial/8250/8250_port.c:3257 [inline] serial8250_console_write+0x134c/0x1ba0 drivers/tty/serial/8250/8250_port.c:3342 console_emit_next_record kernel/printk/printk.c:3129 [inline] console_flush_one_record kernel/printk/printk.c:3215 [inline] console_flush_all+0x745/0xb60 kernel/printk/printk.c:3289 __console_flush_and_unlock kernel/printk/printk.c:3319 [inline] console_unlock+0xbb/0x190 kernel/printk/printk.c:3359 vprintk_emit+0x4f8/0x5f0 kernel/printk/printk.c:2426 _printk+0xcf/0x120 kernel/printk/printk.c:2451 dvb_usb_generic_rw+0x379/0x4d0 drivers/media/usb/dvb-usb/dvb-usb-urb.c:36 cxusb_ctrl_msg+0x10d/0x1e0 drivers/media/usb/dvb-usb/cxusb.c:102 cxusb_rc_query+0x8f/0x160 drivers/media/usb/dvb-usb/cxusb.c:520 dvb_usb_read_remote_control+0xb4/0x1a0 drivers/media/usb/dvb-usb/dvb-usb-remote.c:261 process_one_work kernel/workqueue.c:3257 [inline] process_scheduled_works+0xad1/0x1770 kernel/workqueue.c:3340 worker_thread+0x8a0/0xda0 kernel/workqueue.c:3421 kthread+0x711/0x8a0 kernel/kthread.c:463 ret_from_fork+0x599/0xb30 arch/x86/kernel/process.c:158 ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:246