INFO: task kworker/1:5:5929 blocked for more than 144 seconds. Not tainted syzkaller #0 "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message. task:kworker/1:5 state:D stack:21800 pid:5929 tgid:5929 ppid:2 task_flags:0x4288060 flags:0x00080000 Workqueue: usb_hub_wq hub_event Call Trace: context_switch kernel/sched/core.c:5325 [inline] __schedule+0x1798/0x4cc0 kernel/sched/core.c:6929 __schedule_loop kernel/sched/core.c:7011 [inline] schedule+0x165/0x360 kernel/sched/core.c:7026 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+0x581/0x6e0 drivers/i2c/i2c-core-base.c:1814 ttusb_disconnect+0x204/0x340 drivers/media/usb/ttusb-budget/dvb-ttusb-budget.c:1737 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:1274 [inline] device_release_driver_internal+0x4d9/0x800 drivers/base/dd.c:1297 bus_remove_device+0x34d/0x410 drivers/base/bus.c:579 device_del+0x511/0x8e0 drivers/base/core.c:3878 usb_disable_device+0x3e9/0x8a0 drivers/usb/core/message.c:1418 usb_disconnect+0x330/0x950 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+0x1cf5/0x4a20 drivers/usb/core/hub.c:5952 process_one_work kernel/workqueue.c:3263 [inline] process_scheduled_works+0xae1/0x17b0 kernel/workqueue.c:3346 worker_thread+0x8a0/0xda0 kernel/workqueue.c:3427 kthread+0x711/0x8a0 kernel/kthread.c:463 ret_from_fork+0x4bc/0x870 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/31: #0: ffffffff8e13d2e0 (rcu_read_lock){....}-{1:3}, at: rcu_lock_acquire include/linux/rcupdate.h:331 [inline] #0: ffffffff8e13d2e0 (rcu_read_lock){....}-{1:3}, at: rcu_read_lock include/linux/rcupdate.h:867 [inline] #0: ffffffff8e13d2e0 (rcu_read_lock){....}-{1:3}, at: debug_show_all_locks+0x2e/0x180 kernel/locking/lockdep.c:6775 1 lock held by udevd/5191: 2 locks held by getty/5582: #0: ffff88802fb720a0 (&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+0x43e/0x1400 drivers/tty/n_tty.c:2222 5 locks held by kworker/1:5/5929: #0: ffff88801aedf548 ((wq_completion)usb_hub_wq){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:3238 [inline] #0: ffff88801aedf548 ((wq_completion)usb_hub_wq){+.+.}-{0:0}, at: process_scheduled_works+0x9b4/0x17b0 kernel/workqueue.c:3346 #1: ffffc9000452fba0 ((work_completion)(&hub->events)){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:3239 [inline] #1: ffffc9000452fba0 ((work_completion)(&hub->events)){+.+.}-{0:0}, at: process_scheduled_works+0x9ef/0x17b0 kernel/workqueue.c:3346 #2: ffff888144f6f198 (&dev->mutex){....}-{4:4}, at: device_lock include/linux/device.h:914 [inline] #2: ffff888144f6f198 (&dev->mutex){....}-{4:4}, at: hub_event+0x184/0x4a20 drivers/usb/core/hub.c:5898 #3: ffff888078abb198 (&dev->mutex){....}-{4:4}, at: device_lock include/linux/device.h:914 [inline] #3: ffff888078abb198 (&dev->mutex){....}-{4:4}, at: usb_disconnect+0xf8/0x950 drivers/usb/core/hub.c:2335 #4: ffff888030eb9160 (&dev->mutex){....}-{4:4}, at: device_lock include/linux/device.h:914 [inline] #4: ffff888030eb9160 (&dev->mutex){....}-{4:4}, at: __device_driver_lock drivers/base/dd.c:1096 [inline] #4: ffff888030eb9160 (&dev->mutex){....}-{4:4}, at: device_release_driver_internal+0xb6/0x800 drivers/base/dd.c:1294 2 locks held by kworker/u8:15/9580: #0: ffff88801e364948 ((wq_completion)iou_exit){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:3238 [inline] #0: ffff88801e364948 ((wq_completion)iou_exit){+.+.}-{0:0}, at: process_scheduled_works+0x9b4/0x17b0 kernel/workqueue.c:3346 #1: ffffc90003c7fba0 ((work_completion)(&ctx->exit_work)){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:3239 [inline] #1: ffffc90003c7fba0 ((work_completion)(&ctx->exit_work)){+.+.}-{0:0}, at: process_scheduled_works+0x9ef/0x17b0 kernel/workqueue.c:3346 2 locks held by syz.5.2446/15720: #0: ffff888069adf870 (&fc->uapi_mutex){+.+.}-{4:4}, at: __do_sys_fsconfig fs/fsopen.c:471 [inline] #0: ffff888069adf870 (&fc->uapi_mutex){+.+.}-{4:4}, at: __se_sys_fsconfig+0x758/0x8d0 fs/fsopen.c:350 #1: ffffffff8e142d78 (rcu_state.exp_mutex){+.+.}-{4:4}, at: exp_funnel_lock kernel/rcu/tree_exp.h:311 [inline] #1: ffffffff8e142d78 (rcu_state.exp_mutex){+.+.}-{4:4}, at: synchronize_rcu_expedited+0x2f6/0x730 kernel/rcu/tree_exp.h:957 2 locks held by dhcpcd/15731: #0: ffff888075de3008 (&sb->s_type->i_mutex_key#11){+.+.}-{4:4}, at: inode_lock include/linux/fs.h:980 [inline] #0: ffff888075de3008 (&sb->s_type->i_mutex_key#11){+.+.}-{4:4}, at: __sock_release net/socket.c:661 [inline] #0: ffff888075de3008 (&sb->s_type->i_mutex_key#11){+.+.}-{4:4}, at: sock_close+0x9b/0x240 net/socket.c:1455 #1: ffffffff8e142d78 (rcu_state.exp_mutex){+.+.}-{4:4}, at: exp_funnel_lock kernel/rcu/tree_exp.h:343 [inline] #1: ffffffff8e142d78 (rcu_state.exp_mutex){+.+.}-{4:4}, at: synchronize_rcu_expedited+0x3b9/0x730 kernel/rcu/tree_exp.h:957 1 lock held by rm/15743: ============================================= NMI backtrace for cpu 0 CPU: 0 UID: 0 PID: 31 Comm: khungtaskd Not tainted syzkaller #0 PREEMPT(full) Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 10/02/2025 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] check_hung_uninterruptible_tasks kernel/hung_task.c:332 [inline] watchdog+0xf60/0xfa0 kernel/hung_task.c:495 kthread+0x711/0x8a0 kernel/kthread.c:463 ret_from_fork+0x4bc/0x870 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: 11947 Comm: syz-executor Not tainted syzkaller #0 PREEMPT(full) Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 10/02/2025 RIP: 0010:rcu_is_watching+0x0/0xb0 kernel/rcu/tree.c:747 Code: c7 c7 60 21 14 8e e8 df 03 23 03 eb cc 66 66 66 66 2e 0f 1f 84 00 00 00 00 00 90 90 90 90 90 90 90 90 90 90 90 90 90 90 90 90 0f 1e fa 41 57 41 56 53 65 ff 05 50 c2 ea 10 e8 1b 0d a6 09 89 RSP: 0018:ffffc9001cbd7188 EFLAGS: 00000202 RAX: ffffffff81cf550e RBX: 0000000000000000 RCX: 0000000000000000 RDX: ffff88802a503c80 RSI: 0000000000000001 RDI: 0000000000000000 RBP: 0000000000000001 R08: 0000000000000000 R09: ffffffff81cf5336 R10: dffffc0000000000 R11: ffffffff81ac6cd0 R12: 00000000000005de R13: dffffc0000000000 R14: 00007f803858dc2a R15: 0000000000000000 FS: 0000555593221500(0000) GS:ffff888125e0b000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 00007f1b0ab06440 CR3: 0000000059b5c000 CR4: 0000000000350ef0 Call Trace: rcu_read_unlock include/linux/rcupdate.h:895 [inline] is_bpf_text_address+0x207/0x2b0 kernel/bpf/core.c:746 kernel_text_address+0xa5/0xe0 kernel/extable.c:125 __kernel_text_address+0xd/0x40 kernel/extable.c:79 unwind_get_return_address+0x4d/0x90 arch/x86/kernel/unwind_orc.c:369 arch_stack_walk+0xfc/0x150 arch/x86/kernel/stacktrace.c:26 stack_trace_save+0x9c/0xe0 kernel/stacktrace.c:122 save_stack+0xf5/0x1f0 mm/page_owner.c:156 __reset_page_owner+0x71/0x1f0 mm/page_owner.c:308 reset_page_owner include/linux/page_owner.h:25 [inline] free_pages_prepare mm/page_alloc.c:1394 [inline] free_unref_folios+0xdb3/0x14f0 mm/page_alloc.c:2963 folios_put_refs+0x584/0x670 mm/swap.c:1002 folio_batch_release include/linux/pagevec.h:101 [inline] shmem_undo_range+0x49e/0x14b0 mm/shmem.c:1120 shmem_truncate_range mm/shmem.c:1232 [inline] shmem_evict_inode+0x272/0xa70 mm/shmem.c:1360 evict+0x504/0x9c0 fs/inode.c:810 __dentry_kill+0x209/0x660 fs/dcache.c:669 dput+0x19f/0x2b0 fs/dcache.c:911 __fput+0x68e/0xa70 fs/file_table.c:476 task_work_run+0x1d4/0x260 kernel/task_work.c:227 resume_user_mode_work include/linux/resume_user_mode.h:50 [inline] exit_to_user_mode_loop+0xe9/0x130 kernel/entry/common.c:43 exit_to_user_mode_prepare include/linux/irq-entry-common.h:225 [inline] syscall_exit_to_user_mode_work include/linux/entry-common.h:175 [inline] syscall_exit_to_user_mode include/linux/entry-common.h:210 [inline] do_syscall_64+0x2bd/0xfa0 arch/x86/entry/syscall_64.c:100 entry_SYSCALL_64_after_hwframe+0x77/0x7f RIP: 0033:0x7f803858dc2a Code: 48 3d 00 f0 ff ff 77 48 c3 0f 1f 80 00 00 00 00 48 83 ec 18 89 7c 24 0c e8 43 91 02 00 8b 7c 24 0c 89 c2 b8 03 00 00 00 0f 05 <48> 3d 00 f0 ff ff 77 36 89 d7 89 44 24 0c e8 a3 91 02 00 8b 44 24 RSP: 002b:00007fff816701d0 EFLAGS: 00000293 ORIG_RAX: 0000000000000003 RAX: 0000000000000000 RBX: 0000000000000003 RCX: 00007f803858dc2a RDX: 0000000000000000 RSI: 0000000000000000 RDI: 0000000000000003 RBP: 00007fff8167022c R08: 0000000000000000 R09: 00007fff8166ff37 R10: 0000000000000000 R11: 0000000000000293 R12: 0000000000000089 R13: 00000000000927c0 R14: 00000000000f63e9 R15: 00007fff81670280 vkms_vblank_simulate: vblank timer overrun