INFO: task kworker/u8:1:12736 blocked for more than 143 seconds. Not tainted syzkaller #0 "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message. task:kworker/u8:1 state:D stack:22776 pid:12736 tgid:12736 ppid:2 task_flags:0x4208060 flags:0x00004000 Workqueue: ib-unreg-wq ib_unregister_work Call Trace: context_switch kernel/sched/core.c:5357 [inline] __schedule+0x1190/0x5de0 kernel/sched/core.c:6961 __schedule_loop kernel/sched/core.c:7043 [inline] schedule+0xe7/0x3a0 kernel/sched/core.c:7058 schedule_timeout+0x257/0x290 kernel/time/sleep_timeout.c:75 do_wait_for_common kernel/sched/completion.c:100 [inline] __wait_for_common+0x2fc/0x4e0 kernel/sched/completion.c:121 disable_device+0x16f/0x280 drivers/infiniband/core/device.c:1325 __ib_unregister_device+0x2b4/0x480 drivers/infiniband/core/device.c:1555 ib_unregister_work+0x19/0x30 drivers/infiniband/core/device.c:1667 process_one_work+0x9cc/0x1b70 kernel/workqueue.c:3236 process_scheduled_works kernel/workqueue.c:3319 [inline] worker_thread+0x6c8/0xf10 kernel/workqueue.c:3400 kthread+0x3c2/0x780 kernel/kthread.c:463 ret_from_fork+0x56a/0x730 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: 6 locks held by kworker/1:0/24: #0: ffff88801c6b7d48 ((wq_completion)usb_hub_wq){+.+.}-{0:0}, at: process_one_work+0x12a2/0x1b70 kernel/workqueue.c:3211 #1: ffffc900001e7d10 ((work_completion)(&hub->events)){+.+.}-{0:0}, at: process_one_work+0x929/0x1b70 kernel/workqueue.c:3212 #2: ffff888144fe3198 (&dev->mutex){....}-{4:4}, at: device_lock include/linux/device.h:911 [inline] #2: ffff888144fe3198 (&dev->mutex){....}-{4:4}, at: hub_event+0x1c0/0x4fe0 drivers/usb/core/hub.c:5898 #3: ffff888144fe6518 (&port_dev->status_lock){+.+.}-{4:4}, at: usb_lock_port drivers/usb/core/hub.c:3251 [inline] #3: ffff888144fe6518 (&port_dev->status_lock){+.+.}-{4:4}, at: hub_port_connect drivers/usb/core/hub.c:5463 [inline] #3: ffff888144fe6518 (&port_dev->status_lock){+.+.}-{4:4}, at: hub_port_connect_change drivers/usb/core/hub.c:5706 [inline] #3: ffff888144fe6518 (&port_dev->status_lock){+.+.}-{4:4}, at: port_event drivers/usb/core/hub.c:5870 [inline] #3: ffff888144fe6518 (&port_dev->status_lock){+.+.}-{4:4}, at: hub_event+0x2981/0x4fe0 drivers/usb/core/hub.c:5952 #4: ffff8880b8724088 (psi_seq){-.-.}-{0:0}, at: psi_sched_switch kernel/sched/stats.h:220 [inline] #4: ffff8880b8724088 (psi_seq){-.-.}-{0:0}, at: __schedule+0x1861/0x5de0 kernel/sched/core.c:6955 #5: ffffffff9a898988 (&____s->seqcount#2){----}-{0:0}, at: clockevents_program_event+0x155/0x380 kernel/time/clockevents.c:326 1 lock held by khungtaskd/31: #0: ffffffff8e1c2120 (rcu_read_lock){....}-{1:3}, at: rcu_lock_acquire include/linux/rcupdate.h:331 [inline] #0: ffffffff8e1c2120 (rcu_read_lock){....}-{1:3}, at: rcu_read_lock include/linux/rcupdate.h:841 [inline] #0: ffffffff8e1c2120 (rcu_read_lock){....}-{1:3}, at: debug_show_all_locks+0x36/0x1c0 kernel/locking/lockdep.c:6775 4 locks held by kworker/u8:3/49: #0: ffff88801beec148 ((wq_completion)netns){+.+.}-{0:0}, at: process_one_work+0x12a2/0x1b70 kernel/workqueue.c:3211 #1: ffffc90000b97d10 ( net_cleanup_work ){+.+.}-{0:0}, at: process_one_work+0x929/0x1b70 kernel/workqueue.c:3212 #2: ffffffff8feaad50 (pernet_ops_rwsem){++++}-{4:4}, at: cleanup_net+0xad/0x8b0 net/core/net_namespace.c:669 #3: ffffffff8fec1088 (rtnl_mutex){+.+.}-{4:4}, at: netdev_wait_allrefs_any net/core/dev.c:11374 [inline] #3: ffffffff8fec1088 (rtnl_mutex){+.+.}-{4:4}, at: netdev_run_todo+0xe33/0x1320 net/core/dev.c:11494 2 locks held by getty/5584: #0: ffff888035b420a0 (&tty->ldisc_sem){++++}-{0:0}, at: tty_ldisc_ref_wait+0x24/0x80 drivers/tty/tty_ldisc.c:243 #1: ffffc9000332b2f0 (&ldata->atomic_read_lock){+.+.}-{4:4}, at: n_tty_read+0x41b/0x14f0 drivers/tty/n_tty.c:2222 3 locks held by kworker/u8:10/7104: #0: ffff8880b863a318 (&rq->__lock){-.-.}-{2:2}, at: raw_spin_rq_lock_nested kernel/sched/core.c:644 [inline] #0: ffff8880b863a318 (&rq->__lock){-.-.}-{2:2}, at: raw_spin_rq_lock_nested+0x7e/0x130 kernel/sched/core.c:629 #1: ffff8880b8724088 (psi_seq){-.-.}-{0:0}, at: psi_sched_switch kernel/sched/stats.h:220 [inline] #1: ffff8880b8724088 (psi_seq){-.-.}-{0:0}, at: __schedule+0x1861/0x5de0 kernel/sched/core.c:6955 #2: ffff8880b8725b18 (&base->lock){-.-.}-{2:2}, at: lock_timer_base+0x127/0x1d0 kernel/time/timer.c:1004 3 locks held by kworker/u8:13/8331: #0: ffff88801b081148 ((wq_completion)events_unbound){+.+.}-{0:0}, at: process_one_work+0x12a2/0x1b70 kernel/workqueue.c:3211 #1: ffffc90003d9fd10 ((linkwatch_work).work){+.+.}-{0:0}, at: process_one_work+0x929/0x1b70 kernel/workqueue.c:3212 #2: ffffffff8fec1088 (rtnl_mutex){+.+.}-{4:4}, at: linkwatch_event+0x51/0xc0 net/core/link_watch.c:303 3 locks held by kworker/u8:14/8333: #0: ffff88801b081148 ((wq_completion)events_unbound){+.+.}-{0:0}, at: process_one_work+0x12a2/0x1b70 kernel/workqueue.c:3211 #1: ffffc90003027d10 ((work_completion)(&map->work)){+.+.}-{0:0}, at: process_one_work+0x929/0x1b70 kernel/workqueue.c:3212 #2: ffffffff8e1cd6b8 (rcu_state.exp_mutex){+.+.}-{4:4}, at: exp_funnel_lock+0x284/0x3c0 kernel/rcu/tree_exp.h:311 3 locks held by kworker/u8:17/8339: 3 locks held by kworker/u8:1/12736: #0: ffff8881442ed948 ((wq_completion)ib-unreg-wq){+.+.}-{0:0}, at: process_one_work+0x12a2/0x1b70 kernel/workqueue.c:3211 #1: ffffc9001be9fd10 ((work_completion)(&device->unregistration_work)){+.+.}-{0:0}, at: process_one_work+0x929/0x1b70 kernel/workqueue.c:3212 #2: ffff888033190700 (&device->unregistration_lock){+.+.}-{4:4}, at: __ib_unregister_device+0x23b/0x480 drivers/infiniband/core/device.c:1551 6 locks held by kworker/0:2/16025: #0: ffff88801c6b7d48 ((wq_completion)usb_hub_wq){+.+.}-{0:0}, at: process_one_work+0x12a2/0x1b70 kernel/workqueue.c:3211 #1: ffffc900031d7d10 ((work_completion)(&hub->events)){+.+.}-{0:0}, at: process_one_work+0x929/0x1b70 kernel/workqueue.c:3212 #2: ffff88802903b198 (&dev->mutex){....}-{4:4}, at: device_lock include/linux/device.h:911 [inline] #2: ffff88802903b198 (&dev->mutex){....}-{4:4}, at: hub_event+0x1c0/0x4fe0 drivers/usb/core/hub.c:5898 #3: ffff888052e0e198 (&dev->mutex){....}-{4:4}, at: device_lock include/linux/device.h:911 [inline] #3: ffff888052e0e198 (&dev->mutex){....}-{4:4}, at: __device_attach+0x7e/0x4b0 drivers/base/dd.c:1006 #4: ffff88804b8da160 (&dev->mutex){....}-{4:4}, at: device_lock include/linux/device.h:911 [inline] #4: ffff88804b8da160 (&dev->mutex){....}-{4:4}, at: __device_attach+0x7e/0x4b0 drivers/base/dd.c:1006 #5: ffffffff8fec1088 (rtnl_mutex){+.+.}-{4:4}, at: rtnl_net_lock_killable include/linux/rtnetlink.h:145 [inline] #5: ffffffff8fec1088 (rtnl_mutex){+.+.}-{4:4}, at: register_netdev+0x18/0x50 net/core/dev.c:11319 5 locks held by kworker/0:4/18562: #0: ffff88801c6b7d48 ((wq_completion)usb_hub_wq){+.+.}-{0:0}, at: process_one_work+0x12a2/0x1b70 kernel/workqueue.c:3211 #1: ffffc9000558fd10 ((work_completion)(&hub->events)){+.+.}-{0:0}, at: process_one_work+0x929/0x1b70 kernel/workqueue.c:3212 #2: ffff88802911b198 (&dev->mutex){....}-{4:4}, at: device_lock include/linux/device.h:911 [inline] #2: ffff88802911b198 (&dev->mutex){....}-{4:4}, at: hub_event+0x1c0/0x4fe0 drivers/usb/core/hub.c:5898 #3: ffff888029d2c198 (&dev->mutex){....}-{4:4}, at: device_lock include/linux/device.h:911 [inline] #3: ffff888029d2c198 (&dev->mutex){....}-{4:4}, at: __device_attach+0x7e/0x4b0 drivers/base/dd.c:1006 #4: ffff8880206b7278 (&(&priv->bus_notifier)->rwsem){++++}-{4:4}, at: blocking_notifier_call_chain kernel/notifier.c:379 [inline] #4: ffff8880206b7278 (&(&priv->bus_notifier)->rwsem){++++}-{4:4}, at: blocking_notifier_call_chain+0x53/0xa0 kernel/notifier.c:368 4 locks held by udevd/18764: #0: ffff888066a16b08 (&p->lock){+.+.}-{4:4}, at: seq_read_iter+0xe1/0x12c0 fs/seq_file.c:182 #1: ffff88805a89e088 (&of->mutex#2){+.+.}-{4:4}, at: kernfs_seq_start+0x4f/0x2a0 fs/kernfs/file.c:172 #2: ffff888030a53f08 (kn->active#19){++++}-{0:0}, at: kernfs_get_active_of fs/kernfs/file.c:80 [inline] #2: ffff888030a53f08 (kn->active#19){++++}-{0:0}, at: kernfs_seq_start+0xbc/0x2a0 fs/kernfs/file.c:173 #3: ffff888052e0e198 (&dev->mutex){....}-{4:4}, at: device_lock_interruptible include/linux/device.h:916 [inline] #3: ffff888052e0e198 (&dev->mutex){....}-{4:4}, at: manufacturer_show+0x26/0xa0 drivers/usb/core/sysfs.c:142 4 locks held by udevd/20047: #0: ffff888057b9f418 (&p->lock){+.+.}-{4:4}, at: seq_read_iter+0xe1/0x12c0 fs/seq_file.c:182 #1: ffff888073037c88 (&of->mutex#2){+.+.}-{4:4}, at: kernfs_seq_start+0x4f/0x2a0 fs/kernfs/file.c:172 #2: ffff8880687b72d8 (kn->active#19){++++}-{0:0}, at: kernfs_get_active_of fs/kernfs/file.c:80 [inline] #2: ffff8880687b72d8 (kn->active#19){++++}-{0:0}, at: kernfs_seq_start+0xbc/0x2a0 fs/kernfs/file.c:173 #3: ffff888029d2c198 (&dev->mutex){....}-{4:4}, at: device_lock_interruptible include/linux/device.h:916 [inline] #3: ffff888029d2c198 (&dev->mutex){....}-{4:4}, at: manufacturer_show+0x26/0xa0 drivers/usb/core/sysfs.c:142 2 locks held by syz.3.3730/20457: #0: ffffffff8feaad50 (pernet_ops_rwsem){++++}-{4:4}, at: copy_net_ns+0x2d6/0x690 net/core/net_namespace.c:576 #1: ffff888033190700 (&device->unregistration_lock){+.+.}-{4:4}, at: rdma_dev_change_netns+0x30/0x320 drivers/infiniband/core/device.c:1703 2 locks held by syz.5.4026/21583: #0: ffffffff8fec1088 (rtnl_mutex){+.+.}-{4:4}, at: tun_detach drivers/net/tun.c:634 [inline] #0: ffffffff8fec1088 (rtnl_mutex){+.+.}-{4:4}, at: tun_chr_close+0x38/0x230 drivers/net/tun.c:3436 #1: ffffffff8e1cd6b8 (rcu_state.exp_mutex){+.+.}-{4:4}, at: exp_funnel_lock+0x1a3/0x3c0 kernel/rcu/tree_exp.h:343 1 lock held by syz.4.4032/21614: #0: ffffffff8fec1088 (rtnl_mutex){+.+.}-{4:4}, at: rtnl_lock net/core/rtnetlink.c:80 [inline] #0: ffffffff8fec1088 (rtnl_mutex){+.+.}-{4:4}, at: rtnl_nets_lock net/core/rtnetlink.c:341 [inline] #0: ffffffff8fec1088 (rtnl_mutex){+.+.}-{4:4}, at: rtnl_newlink+0x600/0x2000 net/core/rtnetlink.c:4056 2 locks held by syz.0.4040/21643: #0: ffffffff8fe95368 (br_ioctl_mutex){+.+.}-{4:4}, at: br_ioctl_call+0x34/0xa0 net/socket.c:1212 #1: ffffffff8fec1088 (rtnl_mutex){+.+.}-{4:4}, at: br_ioctl_stub+0xf4/0x4c0 net/bridge/br_ioctl.c:418 2 locks held by syz.0.4040/21644: #0: ffffffff905f4800 (&ops->srcu#2){.+.+}-{0:0}, at: srcu_lock_acquire include/linux/srcu.h:161 [inline] #0: ffffffff905f4800 (&ops->srcu#2){.+.+}-{0:0}, at: srcu_read_lock include/linux/srcu.h:253 [inline] #0: ffffffff905f4800 (&ops->srcu#2){.+.+}-{0:0}, at: rtnl_link_ops_get+0x113/0x2c0 net/core/rtnetlink.c:574 #1: ffffffff8fec1088 (rtnl_mutex){+.+.}-{4:4}, at: rtnl_lock net/core/rtnetlink.c:80 [inline] #1: ffffffff8fec1088 (rtnl_mutex){+.+.}-{4:4}, at: rtnl_nets_lock net/core/rtnetlink.c:341 [inline] #1: ffffffff8fec1088 (rtnl_mutex){+.+.}-{4:4}, at: rtnl_newlink+0x600/0x2000 net/core/rtnetlink.c:4056 1 lock held by syz.1.4042/21652: #0: ffffffff8fec1088 (rtnl_mutex){+.+.}-{4:4}, at: rtnl_net_lock include/linux/rtnetlink.h:130 [inline] #0: ffffffff8fec1088 (rtnl_mutex){+.+.}-{4:4}, at: dev_ioctl+0x1a1/0x10e0 net/core/dev_ioctl.c:864 ============================================= 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 08/18/2025 Call Trace: __dump_stack lib/dump_stack.c:94 [inline] dump_stack_lvl+0x116/0x1f0 lib/dump_stack.c:120 nmi_cpu_backtrace+0x27b/0x390 lib/nmi_backtrace.c:113 nmi_trigger_cpumask_backtrace+0x29c/0x300 lib/nmi_backtrace.c:62 trigger_all_cpu_backtrace include/linux/nmi.h:160 [inline] check_hung_uninterruptible_tasks kernel/hung_task.c:328 [inline] watchdog+0xf0e/0x1260 kernel/hung_task.c:491 kthread+0x3c2/0x780 kernel/kthread.c:463 ret_from_fork+0x56a/0x730 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: 0 Comm: swapper/1 Not tainted syzkaller #0 PREEMPT(full) Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 08/18/2025 RIP: 0010:pv_native_safe_halt+0xf/0x20 arch/x86/kernel/paravirt.c:82 Code: 1f 5d 02 e9 13 0a 03 00 0f 1f 00 90 90 90 90 90 90 90 90 90 90 90 90 90 90 90 90 f3 0f 1e fa 66 90 0f 00 2d 73 78 1b 00 fb f4 cc cc cc cc 66 2e 0f 1f 84 00 00 00 00 00 66 90 90 90 90 90 90 RSP: 0018:ffffc90000197df8 EFLAGS: 000002c2 RAX: 00000000067fa91d RBX: 0000000000000001 RCX: ffffffff8b4e99a9 RDX: 0000000000000000 RSI: ffffffff8d9b0735 RDI: ffffffff8bcf9d40 RBP: ffffed1003b5c488 R08: 0000000000000001 R09: ffffed10170e6655 R10: ffff8880b87332ab R11: 0000000000000000 R12: 0000000000000001 R13: ffff88801dae2440 R14: ffffffff905f0490 R15: 0000000000000000 FS: 0000000000000000(0000) GS:ffff888124f81000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 0000001b34010ff8 CR3: 000000005e3b6000 CR4: 00000000003526f0 Call Trace: arch_safe_halt arch/x86/include/asm/paravirt.h:107 [inline] default_idle+0x13/0x20 arch/x86/kernel/process.c:757 default_idle_call+0x6d/0xb0 kernel/sched/idle.c:122 cpuidle_idle_call kernel/sched/idle.c:190 [inline] do_idle+0x391/0x510 kernel/sched/idle.c:330 cpu_startup_entry+0x4f/0x60 kernel/sched/idle.c:428 start_secondary+0x21d/0x2b0 arch/x86/kernel/smpboot.c:315 common_startup_64+0x13e/0x148