INFO: task kworker/0:6:5954 blocked for more than 143 seconds. Not tainted 6.16.0-rc4-next-20250630-syzkaller #0 "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message. task:kworker/0:6 state:D stack:21128 pid:5954 tgid:5954 ppid:2 task_flags:0x4288060 flags:0x00004000 Workqueue: usb_hub_wq hub_event Call Trace: context_switch kernel/sched/core.c:5313 [inline] __schedule+0x16f5/0x4d00 kernel/sched/core.c:6696 __schedule_loop kernel/sched/core.c:6774 [inline] schedule+0x165/0x360 kernel/sched/core.c:6789 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 __flush_work+0x9b9/0xbc0 kernel/workqueue.c:4247 flush_work kernel/workqueue.c:4268 [inline] flush_delayed_work+0x13e/0x190 kernel/workqueue.c:4290 hub_quiesce+0x1f0/0x330 drivers/usb/core/hub.c:1421 hub_disconnect+0xc8/0x470 drivers/usb/core/hub.c:1821 usb_unbind_interface+0x26b/0x910 drivers/usb/core/driver.c:458 device_remove drivers/base/dd.c:569 [inline] __device_release_driver drivers/base/dd.c:1272 [inline] device_release_driver_internal+0x4d6/0x7c0 drivers/base/dd.c:1295 bus_remove_device+0x34d/0x410 drivers/base/bus.c:579 device_del+0x511/0x8e0 drivers/base/core.c:3880 usb_disable_device+0x3e9/0x8a0 drivers/usb/core/message.c:1418 usb_disconnect+0x330/0x950 drivers/usb/core/hub.c:2349 hub_port_connect drivers/usb/core/hub.c:5411 [inline] hub_port_connect_change drivers/usb/core/hub.c:5711 [inline] port_event drivers/usb/core/hub.c:5871 [inline] hub_event+0x1cdb/0x4a00 drivers/usb/core/hub.c:5953 process_one_work kernel/workqueue.c:3239 [inline] process_scheduled_works+0xae1/0x17b0 kernel/workqueue.c:3322 worker_thread+0x8a0/0xda0 kernel/workqueue.c:3403 kthread+0x70e/0x8a0 kernel/kthread.c:463 ret_from_fork+0x3fc/0x770 arch/x86/kernel/process.c:148 ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:245 INFO: task kworker/0:2:17551 blocked for more than 145 seconds. Not tainted 6.16.0-rc4-next-20250630-syzkaller #0 "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message. task:kworker/0:2 state:D stack:25704 pid:17551 tgid:17551 ppid:2 task_flags:0x4208060 flags:0x00004000 Workqueue: events_power_efficient hub_init_func2 Call Trace: context_switch kernel/sched/core.c:5313 [inline] __schedule+0x16f5/0x4d00 kernel/sched/core.c:6696 __schedule_loop kernel/sched/core.c:6774 [inline] schedule+0x165/0x360 kernel/sched/core.c:6789 schedule_preempt_disabled+0x13/0x30 kernel/sched/core.c:6846 __mutex_lock_common kernel/locking/mutex.c:679 [inline] __mutex_lock+0x724/0xe80 kernel/locking/mutex.c:747 device_lock include/linux/device.h:884 [inline] hub_activate+0xb7/0x1ea0 drivers/usb/core/hub.c:1096 process_one_work kernel/workqueue.c:3239 [inline] process_scheduled_works+0xae1/0x17b0 kernel/workqueue.c:3322 worker_thread+0x8a0/0xda0 kernel/workqueue.c:3403 kthread+0x70e/0x8a0 kernel/kthread.c:463 ret_from_fork+0x3fc/0x770 arch/x86/kernel/process.c:148 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: ffffffff8e13bee0 (rcu_read_lock){....}-{1:3}, at: rcu_lock_acquire include/linux/rcupdate.h:331 [inline] #0: ffffffff8e13bee0 (rcu_read_lock){....}-{1:3}, at: rcu_read_lock include/linux/rcupdate.h:841 [inline] #0: ffffffff8e13bee0 (rcu_read_lock){....}-{1:3}, at: debug_show_all_locks+0x2e/0x180 kernel/locking/lockdep.c:6770 2 locks held by kworker/u8:5/196: #0: ffff8880b8639f58 (&rq->__lock){-.-.}-{2:2}, at: raw_spin_rq_lock_nested+0xad/0x140 kernel/sched/core.c:614 #1: ffff8880b8623f08 (&per_cpu_ptr(group->pcpu, cpu)->seq){-.-.}-{0:0}, at: psi_task_switch+0x39a/0x6d0 kernel/sched/psi.c:991 5 locks held by kworker/0:3/5824: #0: ffff888143ef1548 ((wq_completion)usb_hub_wq){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:3214 [inline] #0: ffff888143ef1548 ((wq_completion)usb_hub_wq){+.+.}-{0:0}, at: process_scheduled_works+0x9b4/0x17b0 kernel/workqueue.c:3322 #1: ffffc9000408fbc0 ((work_completion)(&hub->events)){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:3215 [inline] #1: ffffc9000408fbc0 ((work_completion)(&hub->events)){+.+.}-{0:0}, at: process_scheduled_works+0x9ef/0x17b0 kernel/workqueue.c:3322 #2: ffff888144b64198 (&dev->mutex){....}-{4:4}, at: device_lock include/linux/device.h:884 [inline] #2: ffff888144b64198 (&dev->mutex){....}-{4:4}, at: hub_event+0x184/0x4a00 drivers/usb/core/hub.c:5899 #3: ffff88807a64a198 (&dev->mutex){....}-{4:4}, at: device_lock include/linux/device.h:884 [inline] #3: ffff88807a64a198 (&dev->mutex){....}-{4:4}, at: usb_disconnect+0xf8/0x950 drivers/usb/core/hub.c:2340 #4: ffff88807e5ba160 (&dev->mutex){....}-{4:4}, at: device_lock include/linux/device.h:884 [inline] #4: ffff88807e5ba160 (&dev->mutex){....}-{4:4}, at: __device_driver_lock drivers/base/dd.c:1094 [inline] #4: ffff88807e5ba160 (&dev->mutex){....}-{4:4}, at: device_release_driver_internal+0xb6/0x7c0 drivers/base/dd.c:1292 5 locks held by kworker/0:6/5954: #0: ffff888143ef1548 ((wq_completion)usb_hub_wq){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:3214 [inline] #0: ffff888143ef1548 ((wq_completion)usb_hub_wq){+.+.}-{0:0}, at: process_scheduled_works+0x9b4/0x17b0 kernel/workqueue.c:3322 #1: ffffc90004a77bc0 ((work_completion)(&hub->events)){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:3215 [inline] #1: ffffc90004a77bc0 ((work_completion)(&hub->events)){+.+.}-{0:0}, at: process_scheduled_works+0x9ef/0x17b0 kernel/workqueue.c:3322 #2: ffff888027f63198 (&dev->mutex){....}-{4:4}, at: device_lock include/linux/device.h:884 [inline] #2: ffff888027f63198 (&dev->mutex){....}-{4:4}, at: hub_event+0x184/0x4a00 drivers/usb/core/hub.c:5899 #3: ffff88806e52d198 (&dev->mutex){....}-{4:4}, at: device_lock include/linux/device.h:884 [inline] #3: ffff88806e52d198 (&dev->mutex){....}-{4:4}, at: usb_disconnect+0xf8/0x950 drivers/usb/core/hub.c:2340 #4: ffff888029284160 (&dev->mutex){....}-{4:4}, at: device_lock include/linux/device.h:884 [inline] #4: ffff888029284160 (&dev->mutex){....}-{4:4}, at: __device_driver_lock drivers/base/dd.c:1094 [inline] #4: ffff888029284160 (&dev->mutex){....}-{4:4}, at: device_release_driver_internal+0xb6/0x7c0 drivers/base/dd.c:1292 3 locks held by kworker/0:1/9064: #0: ffff88801a482148 ((wq_completion)events_power_efficient){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:3214 [inline] #0: ffff88801a482148 ((wq_completion)events_power_efficient){+.+.}-{0:0}, at: process_scheduled_works+0x9b4/0x17b0 kernel/workqueue.c:3322 #1: ffffc9000b197bc0 ((work_completion)(&(&hub->init_work)->work)){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:3215 [inline] #1: ffffc9000b197bc0 ((work_completion)(&(&hub->init_work)->work)){+.+.}-{0:0}, at: process_scheduled_works+0x9ef/0x17b0 kernel/workqueue.c:3322 #2: ffff88807a64a198 (&dev->mutex){....}-{4:4}, at: device_lock include/linux/device.h:884 [inline] #2: ffff88807a64a198 (&dev->mutex){....}-{4:4}, at: hub_activate+0xb7/0x1ea0 drivers/usb/core/hub.c:1096 3 locks held by kworker/0:2/17551: #0: ffff88801a482148 ((wq_completion)events_power_efficient){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:3214 [inline] #0: ffff88801a482148 ((wq_completion)events_power_efficient){+.+.}-{0:0}, at: process_scheduled_works+0x9b4/0x17b0 kernel/workqueue.c:3322 #1: ffffc900043afbc0 ((work_completion)(&(&hub->init_work)->work)){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:3215 [inline] #1: ffffc900043afbc0 ((work_completion)(&(&hub->init_work)->work)){+.+.}-{0:0}, at: process_scheduled_works+0x9ef/0x17b0 kernel/workqueue.c:3322 #2: ffff88806e52d198 (&dev->mutex){....}-{4:4}, at: device_lock include/linux/device.h:884 [inline] #2: ffff88806e52d198 (&dev->mutex){....}-{4:4}, at: hub_activate+0xb7/0x1ea0 drivers/usb/core/hub.c:1096 2 locks held by getty/18205: #0: ffff88814ce570a0 (&tty->ldisc_sem){++++}-{0:0}, at: tty_ldisc_ref_wait+0x25/0x70 drivers/tty/tty_ldisc.c:243 #1: ffffc900077432f0 (&ldata->atomic_read_lock){+.+.}-{4:4}, at: n_tty_read+0x43e/0x1400 drivers/tty/n_tty.c:2222 1 lock held by syz.1.2595/18813: #0: ffffffff8e1418c0 (rcu_state.barrier_mutex){+.+.}-{4:4}, at: rcu_barrier+0x4c/0x570 kernel/rcu/tree.c:3792 1 lock held by dhcpcd-run-hook/18841: ============================================= NMI backtrace for cpu 0 CPU: 0 UID: 0 PID: 31 Comm: khungtaskd Not tainted 6.16.0-rc4-next-20250630-syzkaller #0 PREEMPT(full) Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 05/07/2025 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:158 [inline] check_hung_uninterruptible_tasks kernel/hung_task.c:307 [inline] watchdog+0xfee/0x1030 kernel/hung_task.c:470 kthread+0x70e/0x8a0 kernel/kthread.c:463 ret_from_fork+0x3fc/0x770 arch/x86/kernel/process.c:148 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: 18835 Comm: dhcpcd-run-hook Not tainted 6.16.0-rc4-next-20250630-syzkaller #0 PREEMPT(full) Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 05/07/2025 RIP: 0010:slab_update_freelist mm/slub.c:775 [inline] RIP: 0010:__slab_free+0x251/0x3c0 mm/slub.c:4532 Code: ea 48 8b 4c 24 10 4d 89 f8 e8 1b e1 ff ff 41 89 c7 e9 44 fe ff ff 48 8b 5c 24 10 4c 89 f9 4c 89 e0 4c 89 ea f0 48 0f c7 4e 20 <0f> 85 95 fe ff ff 48 85 ed 75 2c 45 85 ed 79 57 65 48 8b 05 17 9b RSP: 0018:ffffc90011d3f490 EFLAGS: 00000242 RAX: ffff888078b7e3c0 RBX: ffff888078b7e8c0 RCX: 00000000000c000a RDX: 00000000000c000b RSI: ffffea0001e2df80 RDI: 0000000000000000 RBP: 0000000000000000 R08: 0000000000000001 R09: 0000000000000000 R10: dffffc0000000000 R11: fffffbfff1f42e87 R12: ffff888078b7e3c0 R13: 00000000000c000b R14: ffff88801e2f98c0 R15: 00000000000c000a FS: 00007fe90ec7ec80(0000) GS:ffff888125d1d000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 0000559721962048 CR3: 0000000061d04000 CR4: 00000000003526f0 Call Trace: qlink_free mm/kasan/quarantine.c:163 [inline] qlist_free_all+0x97/0x140 mm/kasan/quarantine.c:179 kasan_quarantine_reduce+0x148/0x160 mm/kasan/quarantine.c:286 __kasan_slab_alloc+0x22/0x80 mm/kasan/common.c:329 kasan_slab_alloc include/linux/kasan.h:250 [inline] slab_post_alloc_hook mm/slub.c:4180 [inline] slab_alloc_node mm/slub.c:4229 [inline] kmem_cache_alloc_lru_noprof+0x1c6/0x3d0 mm/slub.c:4248 __d_alloc+0x36/0x7a0 fs/dcache.c:1690 d_alloc_parallel+0xe5/0x15e0 fs/dcache.c:2549 __lookup_slow+0x116/0x3d0 fs/namei.c:1793 lookup_slow+0x53/0x70 fs/namei.c:1825 walk_component+0x2d2/0x400 fs/namei.c:2129 lookup_last fs/namei.c:2630 [inline] path_lookupat+0x163/0x430 fs/namei.c:2654 filename_lookup+0x212/0x570 fs/namei.c:2683 vfs_statx+0xf8/0x550 fs/stat.c:353 vfs_fstatat+0x118/0x170 fs/stat.c:375 __do_sys_newfstatat fs/stat.c:542 [inline] __se_sys_newfstatat fs/stat.c:536 [inline] __x64_sys_newfstatat+0x116/0x190 fs/stat.c:536 do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline] do_syscall_64+0xfa/0x3b0 arch/x86/entry/syscall_64.c:94 entry_SYSCALL_64_after_hwframe+0x77/0x7f RIP: 0033:0x7fe90ee38b0a Code: 48 8b 15 f1 f2 0d 00 f7 d8 64 89 02 b8 ff ff ff ff c3 66 2e 0f 1f 84 00 00 00 00 00 0f 1f 40 00 41 89 ca b8 06 01 00 00 0f 05 <3d> 00 f0 ff ff 77 07 31 c0 c3 0f 1f 40 00 48 8b 15 b9 f2 0d 00 f7 RSP: 002b:00007ffd166d1308 EFLAGS: 00000246 ORIG_RAX: 0000000000000106 RAX: ffffffffffffffda RBX: 0000000000000005 RCX: 00007fe90ee38b0a RDX: 00007ffd166d1318 RSI: 0000559721970f58 RDI: 00000000ffffff9c RBP: 0000559721962040 R08: 0000000000000001 R09: 3c00000040001201 R10: 0000000000000000 R11: 0000000000000246 R12: 00007fe90efc0322 R13: 0000000000000000 R14: 0000000000000001 R15: 0000000000000000 vkms_vblank_simulate: vblank timer overrun