INFO: task syz.7.7536:5620 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.7.7536 state:D stack:25336 pid:5620 tgid:5619 ppid:3387 task_flags:0x400140 flags:0x00080002
Call Trace:
context_switch kernel/sched/core.c:5258 [inline]
__schedule+0x150e/0x5070 kernel/sched/core.c:6866
__schedule_loop kernel/sched/core.c:6948 [inline]
schedule+0x165/0x360 kernel/sched/core.c:6963
schedule_preempt_disabled+0x13/0x30 kernel/sched/core.c:7020
__mutex_lock_common kernel/locking/mutex.c:692 [inline]
__mutex_lock+0x7e6/0x1350 kernel/locking/mutex.c:776
device_lock include/linux/device.h:895 [inline]
usbdev_open+0x16e/0x760 drivers/usb/core/devio.c:1054
chrdev_open+0x4cc/0x5e0 fs/char_dev.c:414
do_dentry_open+0x785/0x14e0 fs/open.c:962
vfs_open+0x3b/0x340 fs/open.c:1094
do_open fs/namei.c:4627 [inline]
path_openat+0x2de0/0x3840 fs/namei.c:4786
do_filp_open+0x1fa/0x410 fs/namei.c:4813
do_sys_openat2+0x121/0x200 fs/open.c:1391
do_sys_open fs/open.c:1397 [inline]
__do_sys_openat fs/open.c:1413 [inline]
__se_sys_openat fs/open.c:1408 [inline]
__x64_sys_openat+0x138/0x170 fs/open.c:1408
do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline]
do_syscall_64+0xfa/0xf80 arch/x86/entry/syscall_64.c:94
entry_SYSCALL_64_after_hwframe+0x77/0x7f
RIP: 0033:0x7f98dcd8df90
RSP: 002b:00007f98ddc8cb70 EFLAGS: 00000293 ORIG_RAX: 0000000000000101
RAX: ffffffffffffffda RBX: 0000000000000082 RCX: 00007f98dcd8df90
RDX: 0000000000000082 RSI: 00007f98ddc8cc10 RDI: 00000000ffffff9c
RBP: 00007f98ddc8cc10 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000293 R12: cccccccccccccccd
R13: 00007f98dcfe6038 R14: 00007f98dcfe5fa0 R15: 00007ffd18bc16d8
Showing all locks held in the system:
1 lock held by khungtaskd/31:
#0: ffffffff8e13f2e0 (rcu_read_lock){....}-{1:3}, at: rcu_lock_acquire include/linux/rcupdate.h:331 [inline]
#0: ffffffff8e13f2e0 (rcu_read_lock){....}-{1:3}, at: rcu_read_lock include/linux/rcupdate.h:867 [inline]
#0: ffffffff8e13f2e0 (rcu_read_lock){....}-{1:3}, at: debug_show_all_locks+0x2e/0x180 kernel/locking/lockdep.c:6775
2 locks held by getty/5587:
#0: ffff888030c790a0 (&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+0x449/0x1460 drivers/tty/n_tty.c:2211
2 locks held by kworker/1:6/5941:
#0: ffff88813fe15948 ((wq_completion)events){+.+.}-{0:0}, at: process_one_work+0x841/0x15a0 kernel/workqueue.c:3254
#1: ffffc90004f37b80 (free_ipc_work){+.+.}-{0:0}, at: process_one_work+0x868/0x15a0 kernel/workqueue.c:3255
4 locks held by kworker/1:9/16498:
1 lock held by syz-executor/586:
6 locks held by kworker/1:10/1714:
#0: ffff8880206a1948 ((wq_completion)usb_hub_wq){+.+.}-{0:0}, at: process_one_work+0x841/0x15a0 kernel/workqueue.c:3254
#1: ffffc9000b2d7b80 ((work_completion)(&hub->events)){+.+.}-{0:0}, at: process_one_work+0x868/0x15a0 kernel/workqueue.c:3255
#2: ffff8880295cd198 (&dev->mutex){....}-{4:4}, at: device_lock include/linux/device.h:895 [inline]
#2: ffff8880295cd198 (&dev->mutex){....}-{4:4}, at: hub_event+0x187/0x4ef0 drivers/usb/core/hub.c:5899
#3: ffff8880622b3198 (&dev->mutex){....}-{4:4}, at: device_lock include/linux/device.h:895 [inline]
#3: ffff8880622b3198 (&dev->mutex){....}-{4:4}, at: __device_attach+0x88/0x430 drivers/base/dd.c:1006
#4: ffff88814430d160 (&dev->mutex){....}-{4:4}, at: device_lock include/linux/device.h:895 [inline]
#4: ffff88814430d160 (&dev->mutex){....}-{4:4}, at: __device_attach+0x88/0x430 drivers/base/dd.c:1006
#5: ffffffff8dfe4070 (umhelper_sem){++++}-{4:4}, at: usermodehelper_read_trylock+0xf0/0x2b0 kernel/umh.c:214
5 locks held by kworker/u8:30/3345:
#0: ffff88801baa7148 ((wq_completion)netns){+.+.}-{0:0}, at: process_one_work+0x841/0x15a0 kernel/workqueue.c:3254
#1: ffffc9000bac7b80 (net_cleanup_work){+.+.}-{0:0}, at: process_one_work+0x868/0x15a0 kernel/workqueue.c:3255
#2: ffffffff8f504e10 (pernet_ops_rwsem){++++}-{4:4}, at: cleanup_net+0xf7/0x7a0 net/core/net_namespace.c:670
#3: ffffffff8f512448 (rtnl_mutex){+.+.}-{4:4}, at: ops_exit_rtnl_list net/core/net_namespace.c:173 [inline]
#3: ffffffff8f512448 (rtnl_mutex){+.+.}-{4:4}, at: ops_undo_list+0x2a4/0x990 net/core/net_namespace.c:248
#4: ffffffff8e144e38 (rcu_state.exp_mutex){+.+.}-{4:4}, at: exp_funnel_lock kernel/rcu/tree_exp.h:343 [inline]
#4: ffffffff8e144e38 (rcu_state.exp_mutex){+.+.}-{4:4}, at: synchronize_rcu_expedited+0x3b9/0x730 kernel/rcu/tree_exp.h:956
1 lock held by syz-executor/3615:
5 locks held by syz-executor/3622:
#0: ffff8880a80f0ec0 (&hdev->req_lock){+.+.}-{4:4}, at: hci_dev_do_close net/bluetooth/hci_core.c:499 [inline]
#0: ffff8880a80f0ec0 (&hdev->req_lock){+.+.}-{4:4}, at: hci_unregister_dev+0x212/0x5b0 net/bluetooth/hci_core.c:2715
#1: ffff8880a80f00c0 (&hdev->lock){+.+.}-{4:4}, at: hci_dev_close_sync+0x640/0x1100 net/bluetooth/hci_sync.c:5329
#2: ffffffff8f683f08 (hci_cb_list_lock){+.+.}-{4:4}, at: hci_disconn_cfm include/net/bluetooth/hci_core.h:2151 [inline]
#2: ffffffff8f683f08 (hci_cb_list_lock){+.+.}-{4:4}, at: hci_conn_hash_flush+0xa1/0x260 net/bluetooth/hci_conn.c:2643
#3: ffff888028655338 (&conn->lock#2){+.+.}-{4:4}, at: l2cap_conn_del+0x7b/0x5b0 net/bluetooth/l2cap_core.c:1763
#4: ffffffff8e144e38 (rcu_state.exp_mutex){+.+.}-{4:4}, at: exp_funnel_lock kernel/rcu/tree_exp.h:343 [inline]
#4: ffffffff8e144e38 (rcu_state.exp_mutex){+.+.}-{4:4}, at: synchronize_rcu_expedited+0x3b9/0x730 kernel/rcu/tree_exp.h:956
3 locks held by kworker/0:2/3918:
#0: ffff88813fe15948 ((wq_completion)events){+.+.}-{0:0}, at: process_one_work+0x841/0x15a0 kernel/workqueue.c:3254
#1: ffffc9000437fb80 (deferred_process_work){+.+.}-{0:0}, at: process_one_work+0x868/0x15a0 kernel/workqueue.c:3255
#2: ffffffff8f512448 (rtnl_mutex){+.+.}-{4:4}, at: switchdev_deferred_process_work+0xe/0x20 net/switchdev/switchdev.c:104
1 lock held by syz.7.7536/5620:
#0: ffff8880295cd198 (&dev->mutex){....}-{4:4}, at: device_lock include/linux/device.h:895 [inline]
#0: ffff8880295cd198 (&dev->mutex){....}-{4:4}, at: usbdev_open+0x16e/0x760 drivers/usb/core/devio.c:1054
2 locks held by syz.2.7776/6664:
1 lock held by syz.9.7989/7505:
#0: ffffffff8f512448 (rtnl_mutex){+.+.}-{4:4}, at: tun_detach drivers/net/tun.c:634 [inline]
#0: ffffffff8f512448 (rtnl_mutex){+.+.}-{4:4}, at: tun_chr_close+0x3e/0x1c0 drivers/net/tun.c:3436
4 locks held by syz-executor/7703:
=============================================
NMI backtrace for cpu 1
CPU: 1 UID: 0 PID: 31 Comm: khungtaskd Tainted: G L syzkaller #0 PREEMPT(full)
Tainted: [L]=SOFTLOCKUP
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 10/25/2025
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]
__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:363 [inline]
watchdog+0xe40/0xe90 kernel/hung_task.c:557
kthread+0x711/0x8a0 kernel/kthread.c:463
ret_from_fork+0x599/0xb30 arch/x86/kernel/process.c:158
ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:246
Sending NMI from CPU 1 to CPUs 0:
NMI backtrace for cpu 0
CPU: 0 UID: 0 PID: 32448 Comm: kworker/u9:2 Tainted: G L syzkaller #0 PREEMPT(full)
Tainted: [L]=SOFTLOCKUP
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 10/25/2025
Workqueue: hci0 hci_rx_work
RIP: 0010:__this_cpu_preempt_check+0x7/0x20 lib/smp_processor_id.c:64
Code: 7f e1 ff ff 66 66 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 f3 0f 1e fa 48 89 fe <48> c7 c7 60 79 e0 8b e9 bd fe ff ff cc cc cc cc cc cc cc cc cc cc
RSP: 0018:ffffc90000007740 EFLAGS: 00000002
RAX: 0000000000000001 RBX: ffffffff81856b7e RCX: 20d3b9da412bcc00
RDX: 0000000000000004 RSI: ffffffff8d997e54 RDI: ffffffff8d997e54
RBP: ffffc90000007810 R08: ffffffff89332bb1 R09: ffff8880b8638860
R10: 0000000000000003 R11: 0000000000000100 R12: ffffffff89332820
R13: ffffffff89332820 R14: ffff8880282e8000 R15: 1ffff92000000ef0
FS: 0000000000000000(0000) GS:ffff888125c25000(0000) knlGS:0000000000000000
CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 00007f282dff6d00 CR3: 000000000df38000 CR4: 00000000003526f0
Call Trace:
lockdep_hardirqs_off+0x74/0x100 kernel/locking/lockdep.c:4511
trace_hardirqs_off+0x12/0x40 kernel/trace/trace_preemptirq.c:104
__local_bh_enable_ip+0xce/0x1c0 kernel/softirq.c:432
local_bh_enable include/linux/bottom_half.h:33 [inline]
__alloc_skb+0x224/0x430 net/core/skbuff.c:674
skb_copy+0x188/0x800 net/core/skbuff.c:2162
mac80211_hwsim_tx_frame_no_nl+0xcd3/0x11c0 drivers/net/wireless/virtual/mac80211_hwsim.c:1891
mac80211_hwsim_tx_frame+0x1b5/0x200 drivers/net/wireless/virtual/mac80211_hwsim.c:2264
mac80211_hwsim_beacon_tx+0x3e8/0x870 drivers/net/wireless/virtual/mac80211_hwsim.c:2365
__iterate_interfaces+0x2ab/0x590 net/mac80211/util.c:761
ieee80211_iterate_active_interfaces_atomic+0xdb/0x180 net/mac80211/util.c:797
mac80211_hwsim_beacon+0xbb/0x180 drivers/net/wireless/virtual/mac80211_hwsim.c:2395
__run_hrtimer kernel/time/hrtimer.c:1777 [inline]
__hrtimer_run_queues+0x51c/0xc30 kernel/time/hrtimer.c:1841
hrtimer_run_softirq+0x187/0x2b0 kernel/time/hrtimer.c:1858
handle_softirqs+0x27d/0x850 kernel/softirq.c:626
__do_softirq kernel/softirq.c:660 [inline]
invoke_softirq kernel/softirq.c:496 [inline]
__irq_exit_rcu+0xca/0x1f0 kernel/softirq.c:727
irq_exit_rcu+0x9/0x30 kernel/softirq.c:743
instr_sysvec_apic_timer_interrupt arch/x86/kernel/apic/apic.c:1056 [inline]
sysvec_apic_timer_interrupt+0xa6/0xc0 arch/x86/kernel/apic/apic.c:1056
asm_sysvec_apic_timer_interrupt+0x1a/0x20 arch/x86/include/asm/idtentry.h:697
RIP: 0010:console_trylock_spinning kernel/printk/printk.c:2037 [inline]
RIP: 0010:vprintk_emit+0x4d0/0x5f0 kernel/printk/printk.c:2425
Code: 0f 84 34 ff ff ff e8 4f 71 20 00 fb eb 44 e8 47 71 20 00 e8 f2 6a bc 09 4d 85 f6 74 94 e8 38 71 20 00 fb 48 c7 c7 e0 31 13 8e <31> f6 ba 01 00 00 00 31 c9 41 b8 01 00 00 00 45 31 c9 53 e8 28 26
RSP: 0018:ffffc900034874e0 EFLAGS: 00000283
RAX: ffffffff81a14728 RBX: ffffffff81a14581 RCX: 0000000000100000
RDX: ffffc90016097000 RSI: 0000000000004dcc RDI: ffffffff8e1331e0
RBP: ffffc900034875f0 R08: ffffffff8fa22f77 R09: 1ffffffff1f445ee
R10: dffffc0000000000 R11: fffffbfff1f445ef R12: 0000000000000000
R13: 0000000000000035 R14: 0000000000000200 R15: 1ffff92000690ea0
_printk+0xcf/0x120 kernel/printk/printk.c:2451
bt_warn+0x10b/0x160 net/bluetooth/lib.c:276
hci_cc_func net/bluetooth/hci_event.c:4254 [inline]
hci_cmd_complete_evt+0x486/0xa80 net/bluetooth/hci_event.c:4278
hci_event_func net/bluetooth/hci_event.c:7766 [inline]
hci_event_packet+0x78f/0x1260 net/bluetooth/hci_event.c:7823
hci_rx_work+0x3ee/0x1060 net/bluetooth/hci_core.c:4076
process_one_work+0x93a/0x15a0 kernel/workqueue.c:3279
process_scheduled_works kernel/workqueue.c:3362 [inline]
worker_thread+0x9b0/0xee0 kernel/workqueue.c:3443
kthread+0x711/0x8a0 kernel/kthread.c:463
ret_from_fork+0x599/0xb30 arch/x86/kernel/process.c:158
ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:246