INFO: task kworker/1:7:4395 blocked for more than 144 seconds. Not tainted syzkaller #0 "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message. task:kworker/1:7 state:D stack:21696 pid:4395 ppid:2 flags:0x00004000 Workqueue: usb_hub_wq hub_event Call Trace: context_switch kernel/sched/core.c:5246 [inline] __schedule+0x107f/0x4030 kernel/sched/core.c:6563 schedule+0xb9/0x180 kernel/sched/core.c:6639 schedule_timeout+0xbd/0x2d0 kernel/time/timer.c:2144 do_wait_for_common kernel/sched/completion.c:85 [inline] __wait_for_common kernel/sched/completion.c:106 [inline] wait_for_common kernel/sched/completion.c:117 [inline] wait_for_completion+0x2c2/0x590 kernel/sched/completion.c:138 i2c_del_adapter+0x2d6/0x430 drivers/i2c/i2c-core-base.c:1849 osif_disconnect+0x42/0x80 drivers/i2c/busses/i2c-robotfuzz-osif.c:185 usb_unbind_interface+0x200/0x870 drivers/usb/core/driver.c:457 device_remove drivers/base/dd.c:549 [inline] __device_release_driver drivers/base/dd.c:1279 [inline] device_release_driver_internal+0x4cf/0x7c0 drivers/base/dd.c:1305 bus_remove_device+0x2dd/0x400 drivers/base/bus.c:531 device_del+0x63f/0xa80 drivers/base/core.c:3900 usb_disable_device+0x3e7/0x8a0 drivers/usb/core/message.c:1472 usb_disconnect+0x33c/0x8a0 drivers/usb/core/hub.c:2319 hub_port_connect drivers/usb/core/hub.c:5366 [inline] hub_port_connect_change drivers/usb/core/hub.c:5662 [inline] port_event drivers/usb/core/hub.c:5822 [inline] hub_event+0x1d27/0x5200 drivers/usb/core/hub.c:5904 process_one_work+0x8ab/0x1160 kernel/workqueue.c:2292 worker_thread+0xaf5/0x12a0 kernel/workqueue.c:2439 kthread+0x29d/0x330 kernel/kthread.c:376 ret_from_fork+0x1f/0x30 arch/x86/entry/entry_64.S:295 Showing all locks held in the system: 1 lock held by rcu_tasks_kthre/12: #0: ffffffff8d92e230 (rcu_tasks.tasks_gp_mutex){+.+.}-{3:3}, at: rcu_tasks_one_gp+0x33/0xef0 kernel/rcu/tasks.h:517 1 lock held by rcu_tasks_trace/13: #0: ffffffff8d92ea50 (rcu_tasks_trace.tasks_gp_mutex){+.+.}-{3:3}, at: rcu_tasks_one_gp+0x33/0xef0 kernel/rcu/tasks.h:517 1 lock held by khungtaskd/28: #0: ffffffff8d92d8a0 (rcu_read_lock){....}-{1:2}, at: rcu_lock_acquire include/linux/rcupdate.h:350 [inline] #0: ffffffff8d92d8a0 (rcu_read_lock){....}-{1:2}, at: rcu_read_lock include/linux/rcupdate.h:791 [inline] #0: ffffffff8d92d8a0 (rcu_read_lock){....}-{1:2}, at: debug_show_all_locks+0x51/0x290 kernel/locking/lockdep.c:6669 2 locks held by getty/4029: #0: ffff888031549098 (&tty->ldisc_sem){++++}-{0:0}, at: tty_ldisc_ref_wait+0x21/0x70 drivers/tty/tty_ldisc.c:244 #1: ffffc9000327b2f0 (&ldata->atomic_read_lock){+.+.}-{3:3}, at: n_tty_read+0x41e/0x1360 drivers/tty/n_tty.c:2198 5 locks held by kworker/1:7/4395: #0: ffff888143eb2938 ((wq_completion)usb_hub_wq){+.+.}-{0:0}, at: process_one_work+0x7b4/0x1160 kernel/workqueue.c:2267 #1: ffffc90004557d00 ((work_completion)(&hub->events)){+.+.}-{0:0}, at: process_one_work+0x7b4/0x1160 kernel/workqueue.c:2267 #2: ffff888146312190 (&dev->mutex){....}-{3:3}, at: device_lock include/linux/device.h:885 [inline] #2: ffff888146312190 (&dev->mutex){....}-{3:3}, at: hub_event+0x178/0x5200 drivers/usb/core/hub.c:5850 #3: ffff88802a7be190 (&dev->mutex){....}-{3:3}, at: device_lock include/linux/device.h:885 [inline] #3: ffff88802a7be190 (&dev->mutex){....}-{3:3}, at: usb_disconnect+0xf8/0x8a0 drivers/usb/core/hub.c:2310 #4: ffff888076b26118 (&dev->mutex){....}-{3:3}, at: device_lock include/linux/device.h:885 [inline] #4: ffff888076b26118 (&dev->mutex){....}-{3:3}, at: __device_driver_lock drivers/base/dd.c:1099 [inline] #4: ffff888076b26118 (&dev->mutex){....}-{3:3}, at: device_release_driver_internal+0xb1/0x7c0 drivers/base/dd.c:1302 ============================================= NMI backtrace for cpu 0 CPU: 0 PID: 28 Comm: khungtaskd Not tainted syzkaller #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 10/07/2026 Call Trace: dump_stack_lvl+0x188/0x24e lib/dump_stack.c:106 nmi_cpu_backtrace+0x3e6/0x460 lib/nmi_backtrace.c:111 nmi_trigger_cpumask_backtrace+0x1d4/0x450 lib/nmi_backtrace.c:62 trigger_all_cpu_backtrace include/linux/nmi.h:148 [inline] check_hung_uninterruptible_tasks kernel/hung_task.c:220 [inline] watchdog+0xf0e/0xf50 kernel/hung_task.c:377 kthread+0x29d/0x330 kernel/kthread.c:376 ret_from_fork+0x1f/0x30 arch/x86/entry/entry_64.S:295 Sending NMI from CPU 0 to CPUs 1: NMI backtrace for cpu 1 CPU: 1 PID: 22 Comm: kworker/1:0 Not tainted syzkaller #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 10/07/2026 Workqueue: events_power_efficient wg_ratelimiter_gc_entries RIP: 0010:arch_irqs_disabled_flags arch/x86/include/asm/irqflags.h:125 [inline] RIP: 0010:lock_acquire+0x187/0x4a0 kernel/locking/lockdep.c:5791 Code: 9c 8f 84 24 a0 00 00 00 4c 8b b4 24 a0 00 00 00 43 c6 44 3c 08 f8 fa 48 c7 c7 80 26 8c 8a e8 e0 fe cf 08 65 ff 05 19 79 9e 7e <45> 31 c9 41 f7 c6 00 02 00 00 41 0f 94 c1 48 8b 7c 24 18 8b 74 24 RSP: 0018:ffffc900001c7aa0 EFLAGS: 00000002 RAX: 0000000000000001 RBX: 0000000000000000 RCX: 7003be27c59c1300 RDX: 0000000000000000 RSI: ffffffff8a8c2680 RDI: ffffffff8adf7160 RBP: ffffc900001c7bc0 R08: ffffffff8f00d22f R09: 1ffffffff1e01a45 R10: dffffc0000000000 R11: fffffbfff1e01a46 R12: 1ffff92000038f60 R13: 0000000000000001 R14: 0000000000000246 R15: dffffc0000000000 FS: 0000000000000000(0000) GS:ffff8880b8d00000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 00007f9ecabf62f8 CR3: 0000000030c26000 CR4: 00000000003506e0 DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000 DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400 Call Trace: __raw_spin_lock include/linux/spinlock_api_smp.h:133 [inline] _raw_spin_lock+0x2a/0x40 kernel/locking/spinlock.c:154 spin_lock include/linux/spinlock.h:351 [inline] wg_ratelimiter_gc_entries+0x59/0x450 drivers/net/wireguard/ratelimiter.c:63 process_one_work+0x8ab/0x1160 kernel/workqueue.c:2292 worker_thread+0xaf5/0x12a0 kernel/workqueue.c:2439 kthread+0x29d/0x330 kernel/kthread.c:376 ret_from_fork+0x1f/0x30 arch/x86/entry/entry_64.S:295