INFO: task syz.0.855:8682 blocked for more than 143 seconds. Tainted: G L syzkaller #0 "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message. task:syz.0.855 state:D stack:24336 pid:8682 tgid:8681 ppid:5630 task_flags:0x400040 flags:0x00080002 Call Trace: context_switch kernel/sched/core.c:5520 [inline] __schedule+0x17d4/0x5820 kernel/sched/core.c:7270 __schedule_loop kernel/sched/core.c:7347 [inline] schedule+0x164/0x2b0 kernel/sched/core.c:7362 schedule_preempt_disabled+0x13/0x30 kernel/sched/core.c:7419 __mutex_lock_common kernel/locking/mutex.c:726 [inline] __mutex_lock+0x7c1/0x1550 kernel/locking/mutex.c:821 class_mutex_constructor include/linux/mutex.h:253 [inline] odev_open+0x5c/0xa0 sound/core/seq/oss/seq_oss.c:127 chrdev_open+0x4d9/0x600 fs/char_dev.c:411 do_dentry_open+0x816/0x1380 fs/open.c:996 vfs_open+0x3b/0x340 fs/open.c:1101 do_open fs/namei.c:4837 [inline] path_openat+0x1443/0x1d60 fs/namei.c:5000 do_file_open+0x23e/0x4a0 fs/namei.c:5029 do_sys_openat2+0x115/0x200 fs/open.c:1417 do_sys_open fs/open.c:1423 [inline] __do_sys_openat fs/open.c:1439 [inline] __se_sys_openat fs/open.c:1434 [inline] __x64_sys_openat+0x138/0x170 fs/open.c:1434 do_syscall_x64 arch/x86/entry/syscall_64.c:61 [inline] do_syscall_64+0x166/0x520 arch/x86/entry/syscall_64.c:84 entry_SYSCALL_64_after_hwframe+0x77/0x7f RIP: 0033:0x7f91b0b9e0d9 RSP: 002b:00007f91b1a51028 EFLAGS: 00000246 ORIG_RAX: 0000000000000101 RAX: ffffffffffffffda RBX: 00007f91b0e25fa0 RCX: 00007f91b0b9e0d9 RDX: 00000000001c3783 RSI: 0000200000000080 RDI: ffffffffffffff9c RBP: 00007f91b0c35024 R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000 R13: 00007f91b0e26038 R14: 00007f91b0e25fa0 R15: 00007f91b0f4fa48 Showing all locks held in the system: locks held by khungtaskd/30: 1, last CPU#1: #0: ffffffff8ed5a360 (rcu_read_lock){....}-{1:3}, at: rcu_lock_acquire include/linux/rcupdate.h:300 [inline] #0: ffffffff8ed5a360 (rcu_read_lock){....}-{1:3}, at: rcu_read_lock include/linux/rcupdate.h:840 [inline] #0: ffffffff8ed5a360 (rcu_read_lock){....}-{1:3}, at: debug_show_all_locks+0x2e/0x180 kernel/locking/lockdep.c:6793 locks held by getty/5369: 2, on CPU#0: #0: ffff888035acb0a0 (&tty->ldisc_sem){++++}-{0:0}, at: tty_ldisc_ref_wait+0x25/0x70 drivers/tty/tty_ldisc.c:243 #1: ffffc900032332e8 (&ldata->atomic_read_lock){+.+.}-{4:4}, at: n_tty_read+0x45a/0x1360 drivers/tty/n_tty.c:2211 locks held by kworker/0:8/5715: 6, on CPU#0: #0: ffff88823bed6140 ((wq_completion)usb_hub_wq){+.+.}-{0:0}, at: rcu_lock_acquire include/linux/rcupdate.h:300 [inline] #0: ffff88823bed6140 ((wq_completion)usb_hub_wq){+.+.}-{0:0}, at: rcu_read_lock include/linux/rcupdate.h:840 [inline] #0: ffff88823bed6140 ((wq_completion)usb_hub_wq){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:3352 [inline] #0: ffff88823bed6140 ((wq_completion)usb_hub_wq){+.+.}-{0:0}, at: process_scheduled_works+0x97a/0x1630 kernel/workqueue.c:3470 #1: ffffc90005067c40 ((work_completion)(&hub->events)){+.+.}-{0:0}, at: rcu_lock_acquire include/linux/rcupdate.h:300 [inline] #1: ffffc90005067c40 ((work_completion)(&hub->events)){+.+.}-{0:0}, at: rcu_read_lock include/linux/rcupdate.h:840 [inline] #1: ffffc90005067c40 ((work_completion)(&hub->events)){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:3352 [inline] #1: ffffc90005067c40 ((work_completion)(&hub->events)){+.+.}-{0:0}, at: process_scheduled_works+0x97a/0x1630 kernel/workqueue.c:3470 #2: ffff888029a111d8 (&dev->mutex){....}-{4:4}, at: device_lock include/linux/device.h:1104 [inline] #2: ffff888029a111d8 (&dev->mutex){....}-{4:4}, at: hub_event+0x184/0x4d30 drivers/usb/core/hub.c:5907 #3: ffff888029942568 (&port_dev->status_lock){+.+.}-{4:4}, at: usb_lock_port drivers/usb/core/hub.c:3260 [inline] #3: ffff888029942568 (&port_dev->status_lock){+.+.}-{4:4}, at: hub_port_connect drivers/usb/core/hub.c:5472 [inline] #3: ffff888029942568 (&port_dev->status_lock){+.+.}-{4:4}, at: hub_port_connect_change drivers/usb/core/hub.c:5715 [inline] #3: ffff888029942568 (&port_dev->status_lock){+.+.}-{4:4}, at: port_event drivers/usb/core/hub.c:5879 [inline] #3: ffff888029942568 (&port_dev->status_lock){+.+.}-{4:4}, at: hub_event+0x20a1/0x4d30 drivers/usb/core/hub.c:5961 #4: ffff88802a8dd760 (hcd->address0_mutex){+.+.}-{4:4}, at: hub_port_connect drivers/usb/core/hub.c:5473 [inline] #4: ffff88802a8dd760 (hcd->address0_mutex){+.+.}-{4:4}, at: hub_port_connect_change drivers/usb/core/hub.c:5715 [inline] #4: ffff88802a8dd760 (hcd->address0_mutex){+.+.}-{4:4}, at: port_event drivers/usb/core/hub.c:5879 [inline] #4: ffff88802a8dd760 (hcd->address0_mutex){+.+.}-{4:4}, at: hub_event+0x20c9/0x4d30 drivers/usb/core/hub.c:5961 #5: ffff8880b863b520 (&rq->__lock){-.-.}-{2:2}, at: raw_spin_rq_lock_nested+0xb2/0x160 kernel/sched/core.c:685 locks held by kworker/1:7/5749: 3, on CPU#1: #0: ffff88823bed6140 ((wq_completion)usb_hub_wq){+.+.}-{0:0}, at: rcu_lock_acquire include/linux/rcupdate.h:300 [inline] #0: ffff88823bed6140 ((wq_completion)usb_hub_wq){+.+.}-{0:0}, at: rcu_read_lock include/linux/rcupdate.h:840 [inline] #0: ffff88823bed6140 ((wq_completion)usb_hub_wq){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:3352 [inline] #0: ffff88823bed6140 ((wq_completion)usb_hub_wq){+.+.}-{0:0}, at: process_scheduled_works+0x97a/0x1630 kernel/workqueue.c:3470 #1: ffffc900050e7c40 ((work_completion)(&hub->events)){+.+.}-{0:0}, at: rcu_lock_acquire include/linux/rcupdate.h:300 [inline] #1: ffffc900050e7c40 ((work_completion)(&hub->events)){+.+.}-{0:0}, at: rcu_read_lock include/linux/rcupdate.h:840 [inline] #1: ffffc900050e7c40 ((work_completion)(&hub->events)){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:3352 [inline] #1: ffffc900050e7c40 ((work_completion)(&hub->events)){+.+.}-{0:0}, at: process_scheduled_works+0x97a/0x1630 kernel/workqueue.c:3470 #2: ffff888026a601d8 (&dev->mutex){....}-{4:4}, at: device_lock include/linux/device.h:1104 [inline] #2: ffff888026a601d8 (&dev->mutex){....}-{4:4}, at: hub_event+0x184/0x4d30 drivers/usb/core/hub.c:5907 locks held by kworker/u8:15/6835: 3, on CPU#1: #0: ffff88801b0ac140 ((wq_completion)events_unbound){+.+.}-{0:0}, at: rcu_lock_acquire include/linux/rcupdate.h:300 [inline] #0: ffff88801b0ac140 ((wq_completion)events_unbound){+.+.}-{0:0}, at: rcu_read_lock include/linux/rcupdate.h:840 [inline] #0: ffff88801b0ac140 ((wq_completion)events_unbound){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:3352 [inline] #0: ffff88801b0ac140 ((wq_completion)events_unbound){+.+.}-{0:0}, at: process_scheduled_works+0x97a/0x1630 kernel/workqueue.c:3470 #1: ffffc90005717c40 ((linkwatch_work).work){+.+.}-{0:0}, at: rcu_lock_acquire include/linux/rcupdate.h:300 [inline] #1: ffffc90005717c40 ((linkwatch_work).work){+.+.}-{0:0}, at: rcu_read_lock include/linux/rcupdate.h:840 [inline] #1: ffffc90005717c40 ((linkwatch_work).work){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:3352 [inline] #1: ffffc90005717c40 ((linkwatch_work).work){+.+.}-{0:0}, at: process_scheduled_works+0x97a/0x1630 kernel/workqueue.c:3470 #2: ffffffff902444c0 (rtnl_mutex){+.+.}-{4:4}, at: linkwatch_event+0xe/0x60 net/core/link_watch.c:313 locks held by syz.3.829/8588: 3, on CPU#0: #0: ffffffff901a2820 (register_mutex#4){+.+.}-{4:4}, at: class_mutex_constructor include/linux/mutex.h:253 [inline] #0: ffffffff901a2820 (register_mutex#4){+.+.}-{4:4}, at: odev_release+0x4b/0x70 sound/core/seq/oss/seq_oss.c:140 #1: ffff8880772410b0 (&mdev->open_mutex){+.+.}-{4:4}, at: class_mutex_constructor include/linux/mutex.h:253 [inline] #1: ffff8880772410b0 (&mdev->open_mutex){+.+.}-{4:4}, at: snd_seq_oss_midi_close+0x17e/0x650 sound/core/seq/oss/seq_oss_midi.c:373 #2: ffff88807a73b990 (&grp->list_mutex){++++}-{4:4}, at: class_rwsem_write_constructor include/linux/rwsem.h:270 [inline] #2: ffff88807a73b990 (&grp->list_mutex){++++}-{4:4}, at: snd_seq_port_disconnect+0x54/0x950 sound/core/seq/seq_ports.c:625 locks held by syz.0.855/8682: 1, on CPU#0: #0: ffffffff901a2820 (register_mutex#4){+.+.}-{4:4}, at: class_mutex_constructor include/linux/mutex.h:253 [inline] #0: ffffffff901a2820 (register_mutex#4){+.+.}-{4:4}, at: odev_open+0x5c/0xa0 sound/core/seq/oss/seq_oss.c:127 locks held by udevd/8687: 4, on CPU#0: #0: ffff88807a49ebd8 (&p->lock){+.+.}-{4:4}, at: seq_read_iter+0xa4/0xca0 fs/seq_file.c:183 #1: ffff888029b85480 (&of->mutex#2){+.+.}-{4:4}, at: kernfs_seq_start+0x5d/0x420 fs/kernfs/file.c:165 #2: ffff88807bbb0f08 (kn->active#30){.+.+}-{0:0}, at: kernfs_get_active_of fs/kernfs/file.c:73 [inline] #2: ffff88807bbb0f08 (kn->active#30){.+.+}-{0:0}, at: kernfs_seq_start+0xb2/0x420 fs/kernfs/file.c:166 #3: ffff8880863a81d8 (&dev->mutex){....}-{4:4}, at: device_lock_interruptible include/linux/device.h:1109 [inline] #3: ffff8880863a81d8 (&dev->mutex){....}-{4:4}, at: manufacturer_show+0x26/0xa0 drivers/usb/core/sysfs.c:142 locks held by syz.5.925/8996: 1, on CPU#0: #0: ffffffff901a2820 (register_mutex#4){+.+.}-{4:4}, at: class_mutex_constructor include/linux/mutex.h:253 [inline] #0: ffffffff901a2820 (register_mutex#4){+.+.}-{4:4}, at: odev_open+0x5c/0xa0 sound/core/seq/oss/seq_oss.c:127 locks held by syz.5.925/8997: 1, on CPU#1: #0: ffffffff901a2820 (register_mutex#4){+.+.}-{4:4}, at: class_mutex_constructor include/linux/mutex.h:253 [inline] #0: ffffffff901a2820 (register_mutex#4){+.+.}-{4:4}, at: odev_open+0x5c/0xa0 sound/core/seq/oss/seq_oss.c:127 locks held by syz.5.925/8998: 1, on CPU#1: #0: ffffffff901a2820 (register_mutex#4){+.+.}-{4:4}, at: class_mutex_constructor include/linux/mutex.h:253 [inline] #0: ffffffff901a2820 (register_mutex#4){+.+.}-{4:4}, at: odev_open+0x5c/0xa0 sound/core/seq/oss/seq_oss.c:127 locks held by syz.2.952/9103: 1, on CPU#0: #0: ffffffff901a2820 (register_mutex#4){+.+.}-{4:4}, at: class_mutex_constructor include/linux/mutex.h:253 [inline] #0: ffffffff901a2820 (register_mutex#4){+.+.}-{4:4}, at: odev_open+0x5c/0xa0 sound/core/seq/oss/seq_oss.c:127 locks held by syz.7.956/9117: 1, on CPU#1: #0: ffffffff901a2820 (register_mutex#4){+.+.}-{4:4}, at: class_mutex_constructor include/linux/mutex.h:253 [inline] #0: ffffffff901a2820 (register_mutex#4){+.+.}-{4:4}, at: odev_open+0x5c/0xa0 sound/core/seq/oss/seq_oss.c:127 locks held by syz.6.973/9179: 1, on CPU#0: #0: ffffffff901a2820 (register_mutex#4){+.+.}-{4:4}, at: class_mutex_constructor include/linux/mutex.h:253 [inline] #0: ffffffff901a2820 (register_mutex#4){+.+.}-{4:4}, at: odev_open+0x5c/0xa0 sound/core/seq/oss/seq_oss.c:127 locks held by syz.4.1037/9473: 1, on CPU#1: #0: ffffffff901a2820 (register_mutex#4){+.+.}-{4:4}, at: class_mutex_constructor include/linux/mutex.h:253 [inline] #0: ffffffff901a2820 (register_mutex#4){+.+.}-{4:4}, at: odev_open+0x5c/0xa0 sound/core/seq/oss/seq_oss.c:127 locks held by kworker/u8:25/9718: 4, on CPU#1: #0: ffff88801c2d6140 ((wq_completion)netns){+.+.}-{0:0}, at: rcu_lock_acquire include/linux/rcupdate.h:300 [inline] #0: ffff88801c2d6140 ((wq_completion)netns){+.+.}-{0:0}, at: rcu_read_lock include/linux/rcupdate.h:840 [inline] #0: ffff88801c2d6140 ((wq_completion)netns){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:3352 [inline] #0: ffff88801c2d6140 ((wq_completion)netns){+.+.}-{0:0}, at: process_scheduled_works+0x97a/0x1630 kernel/workqueue.c:3470 #1: ffffc900048c7c40 (net_cleanup_work){+.+.}-{0:0}, at: rcu_lock_acquire include/linux/rcupdate.h:300 [inline] #1: ffffc900048c7c40 (net_cleanup_work){+.+.}-{0:0}, at: rcu_read_lock include/linux/rcupdate.h:840 [inline] #1: ffffc900048c7c40 (net_cleanup_work){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:3352 [inline] #1: ffffc900048c7c40 (net_cleanup_work){+.+.}-{0:0}, at: process_scheduled_works+0x97a/0x1630 kernel/workqueue.c:3470 #2: ffffffff90235c68 (pernet_ops_rwsem){++++}-{4:4}, at: cleanup_net+0xf5/0x810 net/core/net_namespace.c:677 #3: ffffffff902444c0 (rtnl_mutex){+.+.}-{4:4}, at: rtnl_net_lock include/linux/rtnetlink.h:134 [inline] #3: ffffffff902444c0 (rtnl_mutex){+.+.}-{4:4}, at: unregister_netdevice_notifier_net+0x18/0x60 net/core/dev.c:2157 locks held by syz.0.1194/10053: 1, on CPU#1: #0: ffffffff901a2820 (register_mutex#4){+.+.}-{4:4}, at: class_mutex_constructor include/linux/mutex.h:253 [inline] #0: ffffffff901a2820 (register_mutex#4){+.+.}-{4:4}, at: odev_open+0x5c/0xa0 sound/core/seq/oss/seq_oss.c:127 locks held by syz.3.1266/10330: 1, on CPU#0: #0: ffffffff901a2820 (register_mutex#4){+.+.}-{4:4}, at: class_mutex_constructor include/linux/mutex.h:253 [inline] #0: ffffffff901a2820 (register_mutex#4){+.+.}-{4:4}, at: odev_open+0x5c/0xa0 sound/core/seq/oss/seq_oss.c:127 locks held by syz.9.1273/10344: 1, on CPU#1: #0: ffffffff901a2820 (register_mutex#4){+.+.}-{4:4}, at: class_mutex_constructor include/linux/mutex.h:253 [inline] #0: ffffffff901a2820 (register_mutex#4){+.+.}-{4:4}, at: odev_open+0x5c/0xa0 sound/core/seq/oss/seq_oss.c:127 locks held by syz.9.1273/10348: 1, on CPU#0: #0: ffffffff901a2820 (register_mutex#4){+.+.}-{4:4}, at: class_mutex_constructor include/linux/mutex.h:253 [inline] #0: ffffffff901a2820 (register_mutex#4){+.+.}-{4:4}, at: odev_open+0x5c/0xa0 sound/core/seq/oss/seq_oss.c:127 locks held by syz.9.1273/10349: 1, on CPU#1: #0: ffffffff901a2820 (register_mutex#4){+.+.}-{4:4}, at: class_mutex_constructor include/linux/mutex.h:253 [inline] #0: ffffffff901a2820 (register_mutex#4){+.+.}-{4:4}, at: odev_open+0x5c/0xa0 sound/core/seq/oss/seq_oss.c:127 locks held by syz.9.1273/10352: 1, on CPU#0: #0: ffffffff901a2820 (register_mutex#4){+.+.}-{4:4}, at: class_mutex_constructor include/linux/mutex.h:253 [inline] #0: ffffffff901a2820 (register_mutex#4){+.+.}-{4:4}, at: odev_open+0x5c/0xa0 sound/core/seq/oss/seq_oss.c:127 locks held by syz.9.1273/10357: 1, on CPU#0: #0: ffffffff901a2820 (register_mutex#4){+.+.}-{4:4}, at: class_mutex_constructor include/linux/mutex.h:253 [inline] #0: ffffffff901a2820 (register_mutex#4){+.+.}-{4:4}, at: odev_open+0x5c/0xa0 sound/core/seq/oss/seq_oss.c:127 locks held by syz.9.1273/10360: 1, on CPU#1: #0: ffffffff901a2820 (register_mutex#4){+.+.}-{4:4}, at: class_mutex_constructor include/linux/mutex.h:253 [inline] #0: ffffffff901a2820 (register_mutex#4){+.+.}-{4:4}, at: odev_open+0x5c/0xa0 sound/core/seq/oss/seq_oss.c:127 locks held by syz.9.1273/10361: 1, on CPU#0: #0: ffffffff901a2820 (register_mutex#4){+.+.}-{4:4}, at: class_mutex_constructor include/linux/mutex.h:253 [inline] #0: ffffffff901a2820 (register_mutex#4){+.+.}-{4:4}, at: odev_open+0x5c/0xa0 sound/core/seq/oss/seq_oss.c:127 locks held by syz-executor/10475: 7, on CPU#0: #0: ffff88807f8d6460 (sb_writers#7){.+.+}-{0:0}, at: file_start_write include/linux/fs.h:2754 [inline] #0: ffff88807f8d6460 (sb_writers#7){.+.+}-{0:0}, at: vfs_write+0x22b/0xba0 fs/read_write.c:683 #1: ffff88808cc72c80 (&of->mutex){+.+.}-{4:4}, at: kernfs_fop_write_iter+0x1d8/0x540 fs/kernfs/file.c:336 #2: ffff888029a502d8 (kn->active#51){.+.+}-{0:0}, at: kernfs_get_active_of fs/kernfs/file.c:73 [inline] #2: ffff888029a502d8 (kn->active#51){.+.+}-{0:0}, at: kernfs_fop_write_iter+0x22b/0x540 fs/kernfs/file.c:337 #3: ffffffff8fabce80 (nsim_bus_dev_list_lock){+.+.}-{4:4}, at: del_device_store+0xd6/0x370 drivers/net/netdevsim/bus.c:234 #4: ffff88802a533128 (&dev->mutex){....}-{4:4}, at: device_lock include/linux/device.h:1104 [inline] #4: ffff88802a533128 (&dev->mutex){....}-{4:4}, at: __device_driver_lock drivers/base/dd.c:1171 [inline] #4: ffff88802a533128 (&dev->mutex){....}-{4:4}, at: device_release_driver_internal+0xb9/0x880 drivers/base/dd.c:1369 #5: ffff88803397d258 (&devlink->lock_key){+.+.}-{4:4}, at: nsim_drv_remove+0x50/0x170 drivers/net/netdevsim/dev.c:1724 #6: ffffffff8ed60668 (rcu_state.exp_mutex){+.+.}-{4:4}, at: exp_funnel_lock kernel/rcu/tree_exp.h:343 [inline] #6: ffffffff8ed60668 (rcu_state.exp_mutex){+.+.}-{4:4}, at: synchronize_rcu_expedited+0x38d/0x770 kernel/rcu/tree_exp.h:964 locks held by syz-executor/10490: 2, on CPU#1: #0: ffffffff8f9ad308 (&ops->srcu#2){.+.+}-{0:0}, at: rcu_lock_acquire include/linux/rcupdate.h:300 [inline] #0: ffffffff8f9ad308 (&ops->srcu#2){.+.+}-{0:0}, at: rcu_read_lock include/linux/rcupdate.h:840 [inline] #0: ffffffff8f9ad308 (&ops->srcu#2){.+.+}-{0:0}, at: rtnl_link_ops_get+0x23/0x250 net/core/rtnetlink.c:595 #1: ffffffff902444c0 (rtnl_mutex){+.+.}-{4:4}, at: rtnl_lock net/core/rtnetlink.c:80 [inline] #1: ffffffff902444c0 (rtnl_mutex){+.+.}-{4:4}, at: rtnl_nets_lock net/core/rtnetlink.c:366 [inline] #1: ffffffff902444c0 (rtnl_mutex){+.+.}-{4:4}, at: rtnl_newlink+0xc10/0x1c30 net/core/rtnetlink.c:4214 ============================================= NMI backtrace for cpu 1 CPU: 1 UID: 0 PID: 30 Comm: khungtaskd Tainted: G L syzkaller #0 PREEMPT(full) Tainted: [L]=SOFTLOCKUP Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 07/24/2026 Call Trace: dump_stack_lvl+0xe8/0x150 lib/dump_stack.c:120 nmi_cpu_backtrace+0x274/0x2d0 lib/nmi_backtrace.c:123 nmi_trigger_cpumask_backtrace+0x17d/0x390 lib/nmi_backtrace.c:66 trigger_all_cpu_backtrace include/linux/nmi.h:164 [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:353 [inline] watchdog+0xfd7/0x1030 kernel/hung_task.c:561 kthread+0x38b/0x480 kernel/kthread.c:436 ret_from_fork+0x514/0xb70 arch/x86/kernel/process.c:158 ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:245 Sending NMI from CPU 1 to CPUs 0: NMI backtrace for cpu 0 CPU: 0 UID: 0 PID: 58 Comm: kworker/u8:4 Tainted: G L syzkaller #0 PREEMPT(full) Tainted: [L]=SOFTLOCKUP Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 07/24/2026 Workqueue: events_unbound nsim_dev_trap_report_work RIP: 0010:__lock_acquire+0x3e/0x2cf0 kernel/locking/lockdep.c:5109 Code: 05 0f 8a ef 11 48 89 84 24 e0 00 00 00 65 4c 8b 35 df 89 ef 11 31 ed 83 3d fe 0b d7 0e 00 0f 84 6e 13 00 00 49 89 fb 48 8b 07 <48> 3d 20 d5 53 94 0f 84 5c 13 00 00 41 89 cd 41 89 d2 8b 0d 6a dd RSP: 0018:ffffc90000007640 EFLAGS: 00000002 RAX: ffffffff9a9fc3c0 RBX: 0000000000000000 RCX: 0000000000000002 RDX: 0000000000000000 RSI: 0000000000000000 RDI: ffffffff9a9fa788 RBP: 0000000000000000 R08: 0000000000000001 R09: 0000000000000001 R10: 000000000000000b R11: ffffffff9a9fa788 R12: 0000000000000002 R13: ffffffff9a9fa788 R14: ffff88801c3b3e80 R15: 0000000000000046 FS: 0000000000000000(0000) GS:ffff888124cfd000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 0000555555888a38 CR3: 00000000120fc000 CR4: 00000000003526f0 DR0: ffffffffffffffff DR1: 00000000000001f8 DR2: 0000000000000002 DR3: ffffffffefffff15 DR6: 00000000ffff0ff0 DR7: 0000000000000400 Call Trace: lock_acquire+0x106/0x350 kernel/locking/lockdep.c:5886 seqcount_lockdep_reader_access+0x55/0x100 include/linux/seqlock.h:73 ktime_get+0x45/0x220 kernel/time/timekeeping.c:1002 __hrtimer_start_range_ns kernel/time/hrtimer.c:1410 [inline] hrtimer_start_range_ns_common+0x26f/0xb90 kernel/time/hrtimer.c:1508 hrtimer_start_range_ns+0x111/0x3e0 kernel/time/hrtimer.c:1530 hrtimer_start include/linux/hrtimer.h:222 [inline] dummy_urb_enqueue+0x55a/0x780 drivers/usb/gadget/udc/dummy_hcd.c:1332 usb_hcd_submit_urb+0x328/0x1b60 drivers/usb/core/hcd.c:1542 keyspan_irq_recv+0x1864/0x2110 drivers/input/misc/keyspan_remote.c:398 __usb_hcd_giveback_urb+0x378/0x540 drivers/usb/core/hcd.c:1657 dummy_timer+0xa91/0x4cf0 drivers/usb/gadget/udc/dummy_hcd.c:2019 __run_hrtimer kernel/time/hrtimer.c:2067 [inline] __hrtimer_run_queues+0x3bc/0xa10 kernel/time/hrtimer.c:2124 hrtimer_run_softirq+0x1e3/0x2e0 kernel/time/hrtimer.c:2141 handle_softirqs+0x226/0x860 kernel/softirq.c:645 __do_softirq kernel/softirq.c:679 [inline] invoke_softirq kernel/softirq.c:519 [inline] __irq_exit_rcu+0xcb/0x220 kernel/softirq.c:767 irq_exit_rcu+0x9/0x30 kernel/softirq.c:784 instr_sysvec_apic_timer_interrupt arch/x86/kernel/apic/apic.c:1062 [inline] sysvec_apic_timer_interrupt+0xa6/0xc0 arch/x86/kernel/apic/apic.c:1062 asm_sysvec_apic_timer_interrupt+0x1a/0x20 arch/x86/include/asm/idtentry.h:674 RIP: 0010:__raw_spin_unlock_irq include/linux/spinlock_api_smp.h:220 [inline] RIP: 0010:_raw_spin_unlock_irq+0x29/0x50 kernel/locking/spinlock.c:229 Code: 90 f3 0f 1e fa 53 48 89 fb 48 83 c7 18 48 8b 74 24 08 e8 ca 90 c1 f5 48 89 df e8 22 06 c2 f5 e8 fd 2b ee f5 fb bf 01 00 00 00 42 26 b3 f5 65 48 8b 05 ba ed b0 07 48 85 c0 74 07 5b e9 bf 49 RSP: 0018:ffffc900015f7ad0 EFLAGS: 00000206 RAX: 00000000000ec9ed RBX: ffff88801b68b000 RCX: 8000000000000001 RDX: 0000000000000000 RSI: ffffffff8e467f31 RDI: 0000000000000001 RBP: ffffc900015f7ce8 R08: ffffffff90798137 R09: 1ffffffff20f3026 R10: dffffc0000000000 R11: fffffbfff20f3027 R12: dffffc0000000000 R13: ffffffff818f24fa R14: 0000000000000001 R15: 0000000000000000 process_one_work kernel/workqueue.c:3353 [inline] process_scheduled_works+0xa23/0x1630 kernel/workqueue.c:3470 worker_thread+0xa47/0xfb0 kernel/workqueue.c:3551 kthread+0x38b/0x480 kernel/kthread.c:436 ret_from_fork+0x514/0xb70 arch/x86/kernel/process.c:158 ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:245