INFO: task syz.3.1137:9992 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.3.1137 state:D stack:24424 pid:9992 tgid:9990 ppid:5633 task_flags:0x400140 flags:0x00080002 Call Trace: context_switch kernel/sched/core.c:5510 [inline] __schedule+0x17d9/0x56c0 kernel/sched/core.c:7234 __schedule_loop kernel/sched/core.c:7311 [inline] schedule+0x164/0x2b0 kernel/sched/core.c:7326 schedule_preempt_disabled+0x13/0x30 kernel/sched/core.c:7383 __mutex_lock_common kernel/locking/mutex.c:726 [inline] __mutex_lock+0x7bf/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:947 vfs_open+0x3b/0x340 fs/open.c:1052 do_open fs/namei.c:4700 [inline] path_openat+0x2e44/0x3830 fs/namei.c:4863 do_file_open+0x23e/0x4a0 fs/namei.c:4892 do_sys_openat2+0x115/0x200 fs/open.c:1368 do_sys_open fs/open.c:1374 [inline] __do_sys_openat fs/open.c:1390 [inline] __se_sys_openat fs/open.c:1385 [inline] __x64_sys_openat+0x138/0x170 fs/open.c:1385 do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline] do_syscall_64+0x174/0x580 arch/x86/entry/syscall_64.c:94 entry_SYSCALL_64_after_hwframe+0x77/0x7f RIP: 0033:0x7f93d9b9e0d9 RSP: 002b:00007f93dab2e028 EFLAGS: 00000246 ORIG_RAX: 0000000000000101 RAX: ffffffffffffffda RBX: 00007f93d9e25fa0 RCX: 00007f93d9b9e0d9 RDX: 0000000000020001 RSI: 0000200000000000 RDI: ffffffffffffff9c RBP: 00007f93d9c35024 R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000 R13: 00007f93d9e26038 R14: 00007f93d9e25fa0 R15: 00007f93d9f4fa48 INFO: task syz.3.1137:9993 blocked for more than 144 seconds. Tainted: G L syzkaller #0 "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message. task:syz.3.1137 state:D stack:28424 pid:9993 tgid:9990 ppid:5633 task_flags:0x400040 flags:0x00080002 Call Trace: context_switch kernel/sched/core.c:5510 [inline] __schedule+0x17d9/0x56c0 kernel/sched/core.c:7234 __schedule_loop kernel/sched/core.c:7311 [inline] schedule+0x164/0x2b0 kernel/sched/core.c:7326 schedule_preempt_disabled+0x13/0x30 kernel/sched/core.c:7383 __mutex_lock_common kernel/locking/mutex.c:726 [inline] __mutex_lock+0x7bf/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:947 vfs_open+0x3b/0x340 fs/open.c:1052 do_open fs/namei.c:4700 [inline] path_openat+0x2e44/0x3830 fs/namei.c:4863 do_file_open+0x23e/0x4a0 fs/namei.c:4892 do_sys_openat2+0x115/0x200 fs/open.c:1368 do_sys_open fs/open.c:1374 [inline] __do_sys_openat fs/open.c:1390 [inline] __se_sys_openat fs/open.c:1385 [inline] __x64_sys_openat+0x138/0x170 fs/open.c:1385 do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline] do_syscall_64+0x174/0x580 arch/x86/entry/syscall_64.c:94 entry_SYSCALL_64_after_hwframe+0x77/0x7f RIP: 0033:0x7f93d9b9e0d9 RSP: 002b:00007f93dab0d028 EFLAGS: 00000246 ORIG_RAX: 0000000000000101 RAX: ffffffffffffffda RBX: 00007f93d9e26090 RCX: 00007f93d9b9e0d9 RDX: 0000000000000000 RSI: 0000200000000200 RDI: ffffffffffffff9c RBP: 00007f93d9c35024 R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000 R13: 00007f93d9e26128 R14: 00007f93d9e26090 R15: 00007f93d9f4fa48 INFO: task syz.3.1137:9996 blocked for more than 145 seconds. Tainted: G L syzkaller #0 "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message. task:syz.3.1137 state:D stack:26584 pid:9996 tgid:9990 ppid:5633 task_flags:0x400040 flags:0x00080002 Call Trace: context_switch kernel/sched/core.c:5510 [inline] __schedule+0x17d9/0x56c0 kernel/sched/core.c:7234 __schedule_loop kernel/sched/core.c:7311 [inline] schedule+0x164/0x2b0 kernel/sched/core.c:7326 schedule_preempt_disabled+0x13/0x30 kernel/sched/core.c:7383 __mutex_lock_common kernel/locking/mutex.c:726 [inline] __mutex_lock+0x7bf/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:947 vfs_open+0x3b/0x340 fs/open.c:1052 do_open fs/namei.c:4700 [inline] path_openat+0x2e44/0x3830 fs/namei.c:4863 do_file_open+0x23e/0x4a0 fs/namei.c:4892 do_sys_openat2+0x115/0x200 fs/open.c:1368 do_sys_open fs/open.c:1374 [inline] __do_sys_openat fs/open.c:1390 [inline] __se_sys_openat fs/open.c:1385 [inline] __x64_sys_openat+0x138/0x170 fs/open.c:1385 do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline] do_syscall_64+0x174/0x580 arch/x86/entry/syscall_64.c:94 entry_SYSCALL_64_after_hwframe+0x77/0x7f RIP: 0033:0x7f93d9b9e0d9 RSP: 002b:00007f93daaec028 EFLAGS: 00000246 ORIG_RAX: 0000000000000101 RAX: ffffffffffffffea RBX: 00007f93d9e26180 RCX: 00007f93d9b9e0d9 RDX: 000000000000c000 RSI: 00002000000001c0 RDI: ffffffffffffff9c RBP: 00007f93d9c35024 R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000 R13: 00007f93d9e26218 R14: 00007f93d9e26180 R15: 00007f93d9f4fa48 Showing all locks held in the system: 1 lock held by khungtaskd/30: #0: ffffffff8eb59c60 (rcu_read_lock){....}-{1:3}, at: rcu_lock_acquire include/linux/rcupdate.h:300 [inline] #0: ffffffff8eb59c60 (rcu_read_lock){....}-{1:3}, at: rcu_read_lock include/linux/rcupdate.h:840 [inline] #0: ffffffff8eb59c60 (rcu_read_lock){....}-{1:3}, at: debug_show_all_locks+0x2e/0x180 kernel/locking/lockdep.c:6775 9 locks held by kworker/1:1/42: #0: ffff8880226cfd40 ((wq_completion)usb_hub_wq){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:3297 [inline] #0: ffff8880226cfd40 ((wq_completion)usb_hub_wq){+.+.}-{0:0}, at: process_scheduled_works+0xa20/0x14e0 kernel/workqueue.c:3405 #1: ffffc90000b27c40 ((work_completion)(&hub->events)){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:3297 [inline] #1: ffffc90000b27c40 ((work_completion)(&hub->events)){+.+.}-{0:0}, at: process_scheduled_works+0xa20/0x14e0 kernel/workqueue.c:3405 #2: ffff88802a53c1d8 (&dev->mutex){....}-{4:4}, at: device_lock include/linux/device.h:1104 [inline] #2: ffff88802a53c1d8 (&dev->mutex){....}-{4:4}, at: hub_event+0x184/0x4d30 drivers/usb/core/hub.c:5907 #3: ffff88807b1651d8 (&dev->mutex){....}-{4:4}, at: device_lock include/linux/device.h:1104 [inline] #3: ffff88807b1651d8 (&dev->mutex){....}-{4:4}, at: usb_disconnect+0xfc/0x9a0 drivers/usb/core/hub.c:2336 #4: ffff888056a551a0 (&dev->mutex){....}-{4:4}, at: device_lock include/linux/device.h:1104 [inline] #4: ffff888056a551a0 (&dev->mutex){....}-{4:4}, at: __device_driver_lock drivers/base/dd.c:1171 [inline] #4: ffff888056a551a0 (&dev->mutex){....}-{4:4}, at: device_release_driver_internal+0xb9/0x880 drivers/base/dd.c:1369 #5: ffffffff8ff8db40 (register_mutex#6){+.+.}-{4:4}, at: class_mutex_constructor include/linux/mutex.h:253 [inline] #5: ffffffff8ff8db40 (register_mutex#6){+.+.}-{4:4}, at: __usb_audio_disconnect sound/usb/card.c:1096 [inline] #5: ffffffff8ff8db40 (register_mutex#6){+.+.}-{4:4}, at: usb_audio_disconnect+0x72/0x540 sound/usb/card.c:1158 #6: ffff8880795b61b0 (&dev->mutex){....}-{4:4}, at: device_lock include/linux/device.h:1104 [inline] #6: ffff8880795b61b0 (&dev->mutex){....}-{4:4}, at: __device_driver_lock drivers/base/dd.c:1171 [inline] #6: ffff8880795b61b0 (&dev->mutex){....}-{4:4}, at: device_release_driver_internal+0xb9/0x880 drivers/base/dd.c:1369 #7: ffffffff8ff88f00 (register_mutex#7){+.+.}-{4:4}, at: class_mutex_constructor include/linux/mutex.h:253 [inline] #7: ffffffff8ff88f00 (register_mutex#7){+.+.}-{4:4}, at: snd_seq_midisynth_remove+0x66/0x550 sound/core/seq/seq_midi.c:450 #8: ffff8880344949e0 (&grp->list_mutex){+.+.}-{4:4}, at: class_rwsem_write_constructor include/linux/rwsem.h:270 [inline] #8: ffff8880344949e0 (&grp->list_mutex){+.+.}-{4:4}, at: delete_and_unsubscribe_port sound/core/seq/seq_ports.c:571 [inline] #8: ffff8880344949e0 (&grp->list_mutex){+.+.}-{4:4}, at: clear_subscriber_list+0x3a7/0x580 sound/core/seq/seq_ports.c:233 6 locks held by kworker/u8:3/48: #0: ffff88801c296140 ((wq_completion)netns){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:3297 [inline] #0: ffff88801c296140 ((wq_completion)netns){+.+.}-{0:0}, at: process_scheduled_works+0xa20/0x14e0 kernel/workqueue.c:3405 #1: ffffc90000b87c40 (net_cleanup_work){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:3297 [inline] #1: ffffc90000b87c40 (net_cleanup_work){+.+.}-{0:0}, at: process_scheduled_works+0xa20/0x14e0 kernel/workqueue.c:3405 #2: ffffffff90019828 (pernet_ops_rwsem){++++}-{4:4}, at: cleanup_net+0xf5/0x810 net/core/net_namespace.c:673 #3: ffff88807c1a2128 (&dev->mutex){....}-{4:4}, at: device_lock include/linux/device.h:1104 [inline] #3: ffff88807c1a2128 (&dev->mutex){....}-{4:4}, at: devl_dev_lock net/devlink/devl_internal.h:124 [inline] #3: ffff88807c1a2128 (&dev->mutex){....}-{4:4}, at: devlink_pernet_pre_exit+0x129/0x420 net/devlink/core.c:557 #4: ffff88807c1a0258 (&devlink->lock_key#2){+.+.}-{4:4}, at: devl_lock net/devlink/core.c:292 [inline] #4: ffff88807c1a0258 (&devlink->lock_key#2){+.+.}-{4:4}, at: devl_dev_lock net/devlink/devl_internal.h:125 [inline] #4: ffff88807c1a0258 (&devlink->lock_key#2){+.+.}-{4:4}, at: devlink_pernet_pre_exit+0x142/0x420 net/devlink/core.c:557 #5: ffffffff900283c0 (rtnl_mutex){+.+.}-{4:4}, at: rtnl_net_lock include/linux/rtnetlink.h:130 [inline] #5: ffffffff900283c0 (rtnl_mutex){+.+.}-{4:4}, at: rtnl_net_dev_lock+0x257/0x2f0 net/core/dev.c:2163 5 locks held by kworker/1:2/986: #0: ffff8880226cfd40 ((wq_completion)usb_hub_wq){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:3297 [inline] #0: ffff8880226cfd40 ((wq_completion)usb_hub_wq){+.+.}-{0:0}, at: process_scheduled_works+0xa20/0x14e0 kernel/workqueue.c:3405 #1: ffffc90004d17c40 ((work_completion)(&hub->events)){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:3297 [inline] #1: ffffc90004d17c40 ((work_completion)(&hub->events)){+.+.}-{0:0}, at: process_scheduled_works+0xa20/0x14e0 kernel/workqueue.c:3405 #2: ffff888029fe81d8 (&dev->mutex){....}-{4:4}, at: device_lock include/linux/device.h:1104 [inline] #2: ffff888029fe81d8 (&dev->mutex){....}-{4:4}, at: hub_event+0x184/0x4d30 drivers/usb/core/hub.c:5907 #3: ffff888031e6d1d8 (&dev->mutex){....}-{4:4}, at: device_lock include/linux/device.h:1104 [inline] #3: ffff888031e6d1d8 (&dev->mutex){....}-{4:4}, at: __device_attach+0x88/0x450 drivers/base/dd.c:1073 #4: ffff88802a4f9f60 (hcd->bandwidth_mutex){+.+.}-{4:4}, at: usb_set_configuration+0x552/0x2180 drivers/usb/core/message.c:2135 2 locks held by getty/5369: #0: ffff8880360390a0 (&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 5 locks held by kworker/1:4/5673: #0: ffff8880226cfd40 ((wq_completion)usb_hub_wq){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:3297 [inline] #0: ffff8880226cfd40 ((wq_completion)usb_hub_wq){+.+.}-{0:0}, at: process_scheduled_works+0xa20/0x14e0 kernel/workqueue.c:3405 #1: ffffc9000409fc40 ((work_completion)(&hub->events)){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:3297 [inline] #1: ffffc9000409fc40 ((work_completion)(&hub->events)){+.+.}-{0:0}, at: process_scheduled_works+0xa20/0x14e0 kernel/workqueue.c:3405 #2: ffff88802ba131d8 (&dev->mutex){....}-{4:4}, at: device_lock include/linux/device.h:1104 [inline] #2: ffff88802ba131d8 (&dev->mutex){....}-{4:4}, at: hub_event+0x184/0x4d30 drivers/usb/core/hub.c:5907 #3: ffff88802ba10568 (&port_dev->status_lock){+.+.}-{4:4}, at: usb_lock_port drivers/usb/core/hub.c:3260 [inline] #3: ffff88802ba10568 (&port_dev->status_lock){+.+.}-{4:4}, at: hub_port_connect drivers/usb/core/hub.c:5472 [inline] #3: ffff88802ba10568 (&port_dev->status_lock){+.+.}-{4:4}, at: hub_port_connect_change drivers/usb/core/hub.c:5715 [inline] #3: ffff88802ba10568 (&port_dev->status_lock){+.+.}-{4:4}, at: port_event drivers/usb/core/hub.c:5879 [inline] #3: ffff88802ba10568 (&port_dev->status_lock){+.+.}-{4:4}, at: hub_event+0x20a1/0x4d30 drivers/usb/core/hub.c:5961 #4: ffff88802bc3ed60 (hcd->address0_mutex){+.+.}-{4:4}, at: hub_port_connect drivers/usb/core/hub.c:5473 [inline] #4: ffff88802bc3ed60 (hcd->address0_mutex){+.+.}-{4:4}, at: hub_port_connect_change drivers/usb/core/hub.c:5715 [inline] #4: ffff88802bc3ed60 (hcd->address0_mutex){+.+.}-{4:4}, at: port_event drivers/usb/core/hub.c:5879 [inline] #4: ffff88802bc3ed60 (hcd->address0_mutex){+.+.}-{4:4}, at: hub_event+0x20c9/0x4d30 drivers/usb/core/hub.c:5961 3 locks held by kworker/0:10/7523: #0: ffff88801b02b140 ((wq_completion)events){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:3297 [inline] #0: ffff88801b02b140 ((wq_completion)events){+.+.}-{0:0}, at: process_scheduled_works+0xa20/0x14e0 kernel/workqueue.c:3405 #1: ffffc9000dc97c40 (free_ipc_work){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:3297 [inline] #1: ffffc9000dc97c40 (free_ipc_work){+.+.}-{0:0}, at: process_scheduled_works+0xa20/0x14e0 kernel/workqueue.c:3405 #2: ffffffff8eb5ff68 (rcu_state.exp_mutex){+.+.}-{4:4}, at: exp_funnel_lock kernel/rcu/tree_exp.h:343 [inline] #2: ffffffff8eb5ff68 (rcu_state.exp_mutex){+.+.}-{4:4}, at: synchronize_rcu_expedited+0x38d/0x770 kernel/rcu/tree_exp.h:961 5 locks held by kworker/0:11/7524: #0: ffff8880226cfd40 ((wq_completion)usb_hub_wq){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:3297 [inline] #0: ffff8880226cfd40 ((wq_completion)usb_hub_wq){+.+.}-{0:0}, at: process_scheduled_works+0xa20/0x14e0 kernel/workqueue.c:3405 #1: ffffc9000dce7c40 ((work_completion)(&hub->events)){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:3297 [inline] #1: ffffc9000dce7c40 ((work_completion)(&hub->events)){+.+.}-{0:0}, at: process_scheduled_works+0xa20/0x14e0 kernel/workqueue.c:3405 #2: ffff88802a11b1d8 (&dev->mutex){....}-{4:4}, at: device_lock include/linux/device.h:1104 [inline] #2: ffff88802a11b1d8 (&dev->mutex){....}-{4:4}, at: hub_event+0x184/0x4d30 drivers/usb/core/hub.c:5907 #3: ffff8880860be1d8 (&dev->mutex){....}-{4:4}, at: device_lock include/linux/device.h:1104 [inline] #3: ffff8880860be1d8 (&dev->mutex){....}-{4:4}, at: usb_disconnect+0xfc/0x9a0 drivers/usb/core/hub.c:2336 #4: ffff8880448791a0 (&dev->mutex){....}-{4:4}, at: device_lock include/linux/device.h:1104 [inline] #4: ffff8880448791a0 (&dev->mutex){....}-{4:4}, at: __device_driver_lock drivers/base/dd.c:1171 [inline] #4: ffff8880448791a0 (&dev->mutex){....}-{4:4}, at: device_release_driver_internal+0xb9/0x880 drivers/base/dd.c:1369 2 locks held by kworker/0:13/7527: 1 lock held by syz.3.1137/9996: #0: ffff88807a3dcea0 (&hdev->req_lock){+.+.}-{4:4}, at: hci_dev_do_close net/bluetooth/hci_core.c:497 [inline] #0: ffff88807a3dcea0 (&hdev->req_lock){+.+.}-{4:4}, at: hci_unregister_dev+0x22a/0x5b0 net/bluetooth/hci_core.c:2678 1 lock held by syz.0.1145/10029: #0: ffff88802a2ccea0 (&hdev->req_lock){+.+.}-{4:4}, at: hci_dev_do_close net/bluetooth/hci_core.c:497 [inline] #0: ffff88802a2ccea0 (&hdev->req_lock){+.+.}-{4:4}, at: hci_unregister_dev+0x22a/0x5b0 net/bluetooth/hci_core.c:2678 1 lock held by syz.6.1222/10378: #0: ffffffff8ff86a40 (register_mutex#4){+.+.}-{4:4}, at: class_mutex_constructor include/linux/mutex.h:253 [inline] #0: ffffffff8ff86a40 (register_mutex#4){+.+.}-{4:4}, at: odev_release+0x4b/0x70 sound/core/seq/oss/seq_oss.c:140 1 lock held by syz.8.1226/10392: #0: ffff888056ce8ea0 (&hdev->req_lock){+.+.}-{4:4}, at: hci_dev_do_close net/bluetooth/hci_core.c:497 [inline] #0: ffff888056ce8ea0 (&hdev->req_lock){+.+.}-{4:4}, at: hci_unregister_dev+0x22a/0x5b0 net/bluetooth/hci_core.c:2678 1 lock held by cxacru/11064: #0: ffffffff8e9f5988 (umhelper_sem){++++}-{4:4}, at: usermodehelper_read_trylock+0xfc/0x2c0 kernel/umh.c:214 1 lock held by syz.9.1457/11409: #0: ffff888044bacea0 (&hdev->req_lock){+.+.}-{4:4}, at: hci_dev_do_close net/bluetooth/hci_core.c:497 [inline] #0: ffff888044bacea0 (&hdev->req_lock){+.+.}-{4:4}, at: hci_unregister_dev+0x22a/0x5b0 net/bluetooth/hci_core.c:2678 1 lock held by syz.1.1493/11530: #0: ffffffff900283c0 (rtnl_mutex){+.+.}-{4:4}, at: tun_detach drivers/net/tun.c:634 [inline] #0: ffffffff900283c0 (rtnl_mutex){+.+.}-{4:4}, at: tun_chr_close+0x3e/0x1c0 drivers/net/tun.c:3442 3 locks held by syz-executor/11538: #0: ffff88805646cea0 (&hdev->req_lock){+.+.}-{4:4}, at: hci_dev_do_close net/bluetooth/hci_core.c:497 [inline] #0: ffff88805646cea0 (&hdev->req_lock){+.+.}-{4:4}, at: hci_unregister_dev+0x22a/0x5b0 net/bluetooth/hci_core.c:2678 #1: ffff88805646c0b8 (&hdev->lock){+.+.}-{4:4}, at: hci_dev_close_sync+0x61f/0x10a0 net/bluetooth/hci_sync.c:5501 #2: ffffffff901b3f00 (hci_cb_list_lock){+.+.}-{4:4}, at: hci_disconn_cfm include/net/bluetooth/hci_core.h:2151 [inline] #2: ffffffff901b3f00 (hci_cb_list_lock){+.+.}-{4:4}, at: hci_conn_hash_flush+0x99/0x260 net/bluetooth/hci_conn.c:2735 4 locks held by syz.4.1500/11556: #0: ffff888032204ea0 (&hdev->req_lock){+.+.}-{4:4}, at: hci_dev_do_close net/bluetooth/hci_core.c:497 [inline] #0: ffff888032204ea0 (&hdev->req_lock){+.+.}-{4:4}, at: hci_unregister_dev+0x22a/0x5b0 net/bluetooth/hci_core.c:2678 #1: ffff8880322040b8 (&hdev->lock){+.+.}-{4:4}, at: hci_dev_close_sync+0x61f/0x10a0 net/bluetooth/hci_sync.c:5501 #2: ffffffff901b3f00 (hci_cb_list_lock){+.+.}-{4:4}, at: hci_disconn_cfm include/net/bluetooth/hci_core.h:2151 [inline] #2: ffffffff901b3f00 (hci_cb_list_lock){+.+.}-{4:4}, at: hci_conn_hash_flush+0x99/0x260 net/bluetooth/hci_conn.c:2735 #3: ffff888032b4d2f8 (&conn->lock#2){+.+.}-{4:4}, at: l2cap_conn_del+0x9f/0x520 net/bluetooth/l2cap_core.c:1808 ============================================= NMI backtrace for cpu 0 CPU: 0 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:122 nmi_trigger_cpumask_backtrace+0x17a/0x380 lib/nmi_backtrace.c:65 trigger_all_cpu_backtrace include/linux/nmi.h:162 [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+0x388/0x470 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 0 to CPUs 1: NMI backtrace for cpu 1 CPU: 1 UID: 0 PID: 35 Comm: kworker/u8:2 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:stack_trace_save+0x61/0x100 kernel/stacktrace.c:114 Code: 1d 8e 48 c7 44 24 10 a0 fb b1 81 48 89 e3 48 c1 eb 03 48 b9 f1 f1 f1 f1 f8 f8 f8 f3 49 be 00 00 00 00 00 fc ff df 4a 89 0c 33 <42> c7 44 33 08 f3 f3 f3 f3 66 42 c7 44 33 04 00 00 42 c6 44 33 06 RSP: 0018:ffffc90000ab76c0 EFLAGS: 00000a06 RAX: ffffc90000ab76e0 RBX: 1ffff92000156ed8 RCX: f3f8f8f8f1f1f1f1 RDX: 0000000000000000 RSI: 0000000000000040 RDI: ffffc90000ab7770 RBP: ffffc90000ab7760 R08: dffffc0000000000 R09: 0000000000000000 R10: ffffc90000ab7770 R11: fffffbfff20af1e7 R12: ffff8880428d3c80 R13: 0000000000000000 R14: dffffc0000000000 R15: ffffc90000ab7770 FS: 0000000000000000(0000) GS:ffff888125049000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 00005613ead7b5e0 CR3: 000000000e946000 CR4: 00000000003526f0 DR0: ffffffffffffffff DR1: 00000000000001f8 DR2: 0000000000000002 DR3: ffffffffefffff15 DR6: 00000000ffff0ff0 DR7: 0000000000000400 Call Trace: kasan_save_stack mm/kasan/common.c:57 [inline] kasan_save_track+0x3e/0x80 mm/kasan/common.c:78 kasan_save_free_info+0x40/0x50 mm/kasan/generic.c:584 poison_slab_object mm/kasan/common.c:253 [inline] __kasan_slab_free+0x5c/0x80 mm/kasan/common.c:285 kasan_slab_free include/linux/kasan.h:235 [inline] slab_free_hook mm/slub.c:2677 [inline] slab_free mm/slub.c:6377 [inline] kmem_cache_free+0x182/0x650 mm/slub.c:6504 nsim_dev_trap_report drivers/net/netdevsim/dev.c:892 [inline] nsim_dev_trap_report_work+0x7ac/0xb40 drivers/net/netdevsim/dev.c:922 process_one_work kernel/workqueue.c:3322 [inline] process_scheduled_works+0xa8e/0x14e0 kernel/workqueue.c:3405 worker_thread+0xa47/0xfb0 kernel/workqueue.c:3486 kthread+0x388/0x470 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