INFO: task syz.7.733:8736 blocked for more than 143 seconds.
Not tainted syzkaller #0
"echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message.
task:syz.7.733 state:D stack:28016 pid:8736 tgid:8735 ppid:7272 task_flags:0x400140 flags:0x00004004
Call Trace:
context_switch kernel/sched/core.c:5360 [inline]
__schedule+0x1798/0x4cc0 kernel/sched/core.c:6964
__schedule_loop kernel/sched/core.c:7046 [inline]
schedule+0x165/0x360 kernel/sched/core.c:7061
schedule_preempt_disabled+0x13/0x30 kernel/sched/core.c:7118
__mutex_lock_common kernel/locking/mutex.c:676 [inline]
__mutex_lock+0x7e6/0x1350 kernel/locking/mutex.c:760
device_lock include/linux/device.h:914 [inline]
usbdev_open+0x16e/0x760 drivers/usb/core/devio.c:1054
chrdev_open+0x4cc/0x5e0 fs/char_dev.c:414
do_dentry_open+0x953/0x13f0 fs/open.c:965
vfs_open+0x3b/0x340 fs/open.c:1095
do_open fs/namei.c:3887 [inline]
path_openat+0x2ee5/0x3830 fs/namei.c:4046
do_filp_open+0x1fa/0x410 fs/namei.c:4073
do_sys_openat2+0x121/0x1c0 fs/open.c:1435
do_sys_open fs/open.c:1450 [inline]
__do_sys_openat fs/open.c:1466 [inline]
__se_sys_openat fs/open.c:1461 [inline]
__x64_sys_openat+0x138/0x170 fs/open.c:1461
do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline]
do_syscall_64+0xfa/0xfa0 arch/x86/entry/syscall_64.c:94
entry_SYSCALL_64_after_hwframe+0x77/0x7f
RIP: 0033:0x7ff8aad8d510
RSP: 002b:00007ff8abbe5b70 EFLAGS: 00000293 ORIG_RAX: 0000000000000101
RAX: ffffffffffffffda RBX: 0000000000101242 RCX: 00007ff8aad8d510
RDX: 0000000000101242 RSI: 00007ff8abbe5c10 RDI: 00000000ffffff9c
RBP: 00007ff8abbe5c10 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000293 R12: cccccccccccccccd
R13: 00007ff8aafd6038 R14: 00007ff8aafd5fa0 R15: 00007fff791f1298
INFO: task syz.6.741:8759 blocked for more than 144 seconds.
Not tainted syzkaller #0
"echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message.
task:syz.6.741 state:D stack:26280 pid:8759 tgid:8758 ppid:6086 task_flags:0x400140 flags:0x00004004
Call Trace:
context_switch kernel/sched/core.c:5360 [inline]
__schedule+0x1798/0x4cc0 kernel/sched/core.c:6964
__schedule_loop kernel/sched/core.c:7046 [inline]
schedule+0x165/0x360 kernel/sched/core.c:7061
schedule_preempt_disabled+0x13/0x30 kernel/sched/core.c:7118
__mutex_lock_common kernel/locking/mutex.c:676 [inline]
__mutex_lock+0x7e6/0x1350 kernel/locking/mutex.c:760
device_lock include/linux/device.h:914 [inline]
usbdev_open+0x16e/0x760 drivers/usb/core/devio.c:1054
chrdev_open+0x4cc/0x5e0 fs/char_dev.c:414
do_dentry_open+0x953/0x13f0 fs/open.c:965
vfs_open+0x3b/0x340 fs/open.c:1095
do_open fs/namei.c:3887 [inline]
path_openat+0x2ee5/0x3830 fs/namei.c:4046
do_filp_open+0x1fa/0x410 fs/namei.c:4073
do_sys_openat2+0x121/0x1c0 fs/open.c:1435
do_sys_open fs/open.c:1450 [inline]
__do_sys_openat fs/open.c:1466 [inline]
__se_sys_openat fs/open.c:1461 [inline]
__x64_sys_openat+0x138/0x170 fs/open.c:1461
do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline]
do_syscall_64+0xfa/0xfa0 arch/x86/entry/syscall_64.c:94
entry_SYSCALL_64_after_hwframe+0x77/0x7f
RIP: 0033:0x7f5f5fb8d510
RSP: 002b:00007f5f60a58b70 EFLAGS: 00000293 ORIG_RAX: 0000000000000101
RAX: ffffffffffffffda RBX: 0000000000101301 RCX: 00007f5f5fb8d510
RDX: 0000000000101301 RSI: 00007f5f60a58c10 RDI: 00000000ffffff9c
RBP: 00007f5f60a58c10 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000293 R12: cccccccccccccccd
R13: 00007f5f5fdd6038 R14: 00007f5f5fdd5fa0 R15: 00007fff96ba21d8
Showing all locks held in the system:
6 locks held by kworker/0:0/9:
1 lock held by khungtaskd/31:
#0: ffffffff8e53c560 (rcu_read_lock){....}-{1:3}, at: rcu_lock_acquire include/linux/rcupdate.h:331 [inline]
#0: ffffffff8e53c560 (rcu_read_lock){....}-{1:3}, at: rcu_read_lock include/linux/rcupdate.h:841 [inline]
#0: ffffffff8e53c560 (rcu_read_lock){....}-{1:3}, at: debug_show_all_locks+0x2e/0x180 kernel/locking/lockdep.c:6775
2 locks held by getty/5626:
#0: ffff88814d90f0a0 (&tty->ldisc_sem){++++}-{0:0}, at: tty_ldisc_ref_wait+0x25/0x70 drivers/tty/tty_ldisc.c:243
#1: ffffc9000332e2f0 (&ldata->atomic_read_lock){+.+.}-{4:4}, at: n_tty_read+0x43e/0x1400 drivers/tty/n_tty.c:2222
4 locks held by udevd/5870:
#0: ffff88805edd0d58
(&p->lock){+.+.}-{4:4}, at: seq_read_iter+0xb7/0xe20 fs/seq_file.c:182
#1: ffff888059b87c88 (&of->mutex#2){+.+.}-{4:4}, at: kernfs_seq_start+0x5c/0x420 fs/kernfs/file.c:172
#2: ffff88805abfa878 (kn->active#19){++++}-{0:0}, at: kernfs_get_active_of fs/kernfs/file.c:80 [inline]
#2: ffff88805abfa878 (kn->active#19){++++}-{0:0}, at: kernfs_seq_start+0xb2/0x420 fs/kernfs/file.c:173
#3: ffff888076926198 (&dev->mutex){....}-{4:4}, at: device_lock_interruptible include/linux/device.h:919 [inline]
#3: ffff888076926198 (&dev->mutex){....}-{4:4}, at: manufacturer_show+0x26/0xa0 drivers/usb/core/sysfs.c:142
5 locks held by kworker/0:4/5913:
#0: ffff888144688d48 ((wq_completion)usb_hub_wq){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:3238 [inline]
#0: ffff888144688d48 ((wq_completion)usb_hub_wq){+.+.}-{0:0}, at: process_scheduled_works+0x9b4/0x17b0 kernel/workqueue.c:3346
#1: ffffc900042bfba0 ((work_completion)(&hub->events)){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:3239 [inline]
#1: ffffc900042bfba0 ((work_completion)(&hub->events)){+.+.}-{0:0}, at: process_scheduled_works+0x9ef/0x17b0 kernel/workqueue.c:3346
#2: ffff888144bff198 (&dev->mutex){....}-{4:4}, at: device_lock include/linux/device.h:914 [inline]
#2: ffff888144bff198 (&dev->mutex){....}-{4:4}, at: hub_event+0x184/0x4a20 drivers/usb/core/hub.c:5898
#3: ffff88807d713198 (&dev->mutex){....}-{4:4}, at: device_lock include/linux/device.h:914 [inline]
#3: ffff88807d713198 (&dev->mutex){....}-{4:4}, at: __device_attach+0x88/0x400 drivers/base/dd.c:1006
#4: ffff888032d72160 (&dev->mutex){....}-{4:4}, at: device_lock include/linux/device.h:914 [inline]
#4: ffff888032d72160 (&dev->mutex){....}-{4:4}, at: __device_attach+0x88/0x400 drivers/base/dd.c:1006
4 locks held by kworker/0:5/5920:
#0: ffff8880b8639f98 (&rq->__lock){-.-.}-{2:2}, at: raw_spin_rq_lock_nested+0x2a/0x140 kernel/sched/core.c:636
#1: ffff8880b8624008 (psi_seq){-.-.}-{0:0}, at: psi_task_switch+0x53/0x880 kernel/sched/psi.c:933
#2: ffffe8ffffc9bb98 (&ACCESS_PRIVATE(sdp, lock)){....}-{3:3}, at: spin_lock_irq include/linux/spinlock.h:376 [inline]
#2: ffffe8ffffc9bb98 (&ACCESS_PRIVATE(sdp, lock)){....}-{3:3}, at: srcu_invoke_callbacks+0x30b/0x450 kernel/rcu/srcutree.c:1816
#3: ffffffff9a1c2ad8 (&obj_hash[i].lock){-.-.}-{2:2}, at: debug_object_activate+0xbb/0x420 lib/debugobjects.c:818
2 locks held by dhcpcd/6435:
#0: ffff88805adbde08 (&sb->s_type->i_mutex_key#11){+.+.}-{4:4}, at: inode_lock include/linux/fs.h:861 [inline]
#0: ffff88805adbde08 (&sb->s_type->i_mutex_key#11){+.+.}-{4:4}, at: __sock_release net/socket.c:648 [inline]
#0: ffff88805adbde08 (&sb->s_type->i_mutex_key#11){+.+.}-{4:4}, at: sock_close+0x9b/0x240 net/socket.c:1439
#1: ffffffff8e541ff8 (rcu_state.exp_mutex){+.+.}-{4:4}, at: exp_funnel_lock kernel/rcu/tree_exp.h:311 [inline]
#1: ffffffff8e541ff8 (rcu_state.exp_mutex){+.+.}-{4:4}, at: synchronize_rcu_expedited+0x2f6/0x730 kernel/rcu/tree_exp.h:957
1 lock held by syz.7.733/8736:
#0: ffff8880281cd198 (&dev->mutex){....}-{4:4}, at: device_lock include/linux/device.h:914 [inline]
#0: ffff8880281cd198 (&dev->mutex){....}-{4:4}, at: usbdev_open+0x16e/0x760 drivers/usb/core/devio.c:1054
1 lock held by syz.6.741/8759:
#0: ffff8880281cd198 (&dev->mutex){....}-{4:4}, at: device_lock include/linux/device.h:914 [inline]
#0: ffff8880281cd198 (&dev->mutex){....}-{4:4}, at: usbdev_open+0x16e/0x760 drivers/usb/core/devio.c:1054
1 lock held by syz.3.778/8860:
#0: ffff8880281cd198 (&dev->mutex){....}-{4:4}, at: device_lock include/linux/device.h:914 [inline]
#0: ffff8880281cd198 (&dev->mutex){....}-{4:4}, at: usbdev_open+0x16e/0x760 drivers/usb/core/devio.c:1054
1 lock held by syz.9.939/9594:
#0: ffff8880281cd198 (&dev->mutex){....}-{4:4}, at: device_lock include/linux/device.h:914 [inline]
#0: ffff8880281cd198 (&dev->mutex){....}-{4:4}, at: usbdev_open+0x16e/0x760 drivers/usb/core/devio.c:1054
1 lock held by syz.8.953/9640:
#0: ffffffff8e541ec0 (rcu_state.barrier_mutex){+.+.}-{4:4}, at: rcu_barrier+0x4c/0x570 kernel/rcu/tree.c:3820
3 locks held by syz-executor/10584:
#0: ffff888020f30dc8 (&hdev->req_lock){+.+.}-{4:4}, at: hci_dev_do_close net/bluetooth/hci_core.c:499 [inline]
#0: ffff888020f30dc8 (&hdev->req_lock){+.+.}-{4:4}, at: hci_unregister_dev+0x212/0x510 net/bluetooth/hci_core.c:2715
#1: ffff888020f300b8 (&hdev->lock){+.+.}-{4:4}, at: hci_dev_close_sync+0x66a/0x1330 net/bluetooth/hci_sync.c:5289
#2: ffffffff8fab69e8 (hci_cb_list_lock){+.+.}-{4:4}, at: hci_disconn_cfm include/net/bluetooth/hci_core.h:2097 [inline]
#2: ffffffff8fab69e8 (hci_cb_list_lock){+.+.}-{4:4}, at: hci_conn_hash_flush+0xa1/0x230 net/bluetooth/hci_conn.c:2602
3 locks held by syz.2.1276/10839:
#0: ffff8880542acdc8 (&hdev->req_lock){+.+.}-{4:4}, at: hci_dev_do_close net/bluetooth/hci_core.c:499 [inline]
#0: ffff8880542acdc8 (&hdev->req_lock){+.+.}-{4:4}, at: hci_unregister_dev+0x212/0x510 net/bluetooth/hci_core.c:2715
#1: ffff8880542ac0b8 (&hdev->lock){+.+.}-{4:4}, at: hci_dev_close_sync+0x66a/0x1330 net/bluetooth/hci_sync.c:5289
#2: ffffffff8fab69e8 (hci_cb_list_lock){+.+.}-{4:4}, at: hci_disconn_cfm include/net/bluetooth/hci_core.h:2097 [inline]
#2: ffffffff8fab69e8 (hci_cb_list_lock){+.+.}-{4:4}, at: hci_conn_hash_flush+0xa1/0x230 net/bluetooth/hci_conn.c:2602
5 locks held by syz.1.1280/10859:
#0: ffff888054c94dc8 (&hdev->req_lock){+.+.}-{4:4}, at: hci_dev_do_close net/bluetooth/hci_core.c:499 [inline]
#0: ffff888054c94dc8 (&hdev->req_lock){+.+.}-{4:4}, at: hci_unregister_dev+0x212/0x510 net/bluetooth/hci_core.c:2715
#1: ffff888054c940b8 (&hdev->lock){+.+.}-{4:4}, at: hci_dev_close_sync+0x66a/0x1330 net/bluetooth/hci_sync.c:5289
#2: ffffffff8fab69e8 (hci_cb_list_lock){+.+.}-{4:4}, at: hci_disconn_cfm include/net/bluetooth/hci_core.h:2097 [inline]
#2: ffffffff8fab69e8 (hci_cb_list_lock){+.+.}-{4:4}, at: hci_conn_hash_flush+0xa1/0x230 net/bluetooth/hci_conn.c:2602
#3: ffff88803246d338 (&conn->lock#2){+.+.}-{4:4}, at: l2cap_conn_del+0x70/0x680 net/bluetooth/l2cap_core.c:1762
#4: ffffffff8e541ff8 (rcu_state.exp_mutex){+.+.}-{4:4}, at: exp_funnel_lock kernel/rcu/tree_exp.h:343 [inline]
#4: ffffffff8e541ff8 (rcu_state.exp_mutex){+.+.}-{4:4}, at: synchronize_rcu_expedited+0x3b9/0x730 kernel/rcu/tree_exp.h:957
1 lock held by syz.8.1282/10870:
#0: ffffffff8e541ec0 (rcu_state.barrier_mutex){+.+.}-{4:4}, at: rcu_barrier+0x4c/0x570 kernel/rcu/tree.c:3820
3 locks held by dhcpcd-run-hook/10898:
=============================================
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 07/12/2025
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]
check_hung_uninterruptible_tasks kernel/hung_task.c:332 [inline]
watchdog+0xf60/0xfa0 kernel/hung_task.c:495
kthread+0x711/0x8a0 kernel/kthread.c:463
ret_from_fork+0x47c/0x820 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: 5953 Comm: kworker/1:4 Not tainted syzkaller #0 PREEMPT(full)
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 07/12/2025
Workqueue: usb_hub_wq hub_event
RIP: 0010:irqtime_account_irq+0x5/0x1c0 kernel/sched/cputime.c:57
Code: 00 00 00 e9 cd 03 f5 09 cc 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 66 0f 1f 00 55 <41> 57 41 56 41 55 41 54 53 89 f5 49 89 fe e8 c8 39 f2 09 89 c3 83
RSP: 0018:ffffc90000a08f50 EFLAGS: 00000046
RAX: 0000000000000802 RBX: ffff88807f6fbc80 RCX: 7e6c55aa9d387300
RDX: 0000000000000000 RSI: 0000000000000000 RDI: ffff88807f6fbc80
RBP: ffffc90000a08fe0 R08: ffffffff8fe50637 R09: 1ffffffff1fca0c6
R10: dffffc0000000000 R11: fffffbfff1fca0c7 R12: 0000000000000000
R13: 0000000000000000 R14: 1ffff920001411ec R15: dffffc0000000000
FS: 0000000000000000(0000) GS:ffff8881258b3000(0000) knlGS:0000000000000000
CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 00007fc03c981d20 CR3: 00000000313d0000 CR4: 00000000003526f0
DR0: 0000000000000007 DR1: 000000000000000b DR2: 0000000000000002
DR3: 0000000000000009 DR6: 00000000ffff0ff0 DR7: 0000000000000400
Call Trace:
account_hardirq_exit include/linux/vtime.h:154 [inline]
__irq_exit_rcu+0x8d/0x1f0 kernel/softirq.c:677
irq_exit_rcu+0x9/0x30 kernel/softirq.c:696
instr_sysvec_apic_timer_interrupt arch/x86/kernel/apic/apic.c:1052 [inline]
sysvec_apic_timer_interrupt+0xa6/0xc0 arch/x86/kernel/apic/apic.c:1052
asm_sysvec_apic_timer_interrupt+0x1a/0x20 arch/x86/include/asm/idtentry.h:697
RIP: 0010:console_trylock_spinning kernel/printk/printk.c:2034 [inline]
RIP: 0010:vprintk_emit+0x49d/0x590 kernel/printk/printk.c:2422
Code: 0f 84 34 ff ff ff e8 52 99 1f 00 fb eb 44 e8 4a 99 1f 00 e8 45 3f e9 09 4d 85 f6 74 94 e8 3b 99 1f 00 fb 48 c7 c7 80 05 53 8e <31> f6 ba 01 00 00 00 31 c9 41 b8 01 00 00 00 45 31 c9 53 e8 6b 3b
RSP: 0018:ffffc900044ff2a0 EFLAGS: 00000293
RAX: ffffffff81a062d5 RBX: ffffffff81a0612e RCX: ffff88807f6fbc80
RDX: 0000000000000000 RSI: 0000000000000000 RDI: ffffffff8e530580
RBP: ffffc900044ff3b0 R08: ffffffff8fe50637 R09: 1ffffffff1fca0c6
R10: dffffc0000000000 R11: fffffbfff1fca0c7 R12: 0000000000000000
R13: 0000000000000029 R14: 0000000000000200 R15: 1ffff9200089fe58
dev_vprintk_emit+0x337/0x3f0 drivers/base/core.c:4914
dev_printk_emit+0xe0/0x130 drivers/base/core.c:4925
_dev_info+0x10a/0x160 drivers/base/core.c:4983
usb_disconnect+0xdd/0x950 drivers/usb/core/hub.c:2326
hub_port_connect drivers/usb/core/hub.c:5406 [inline]
hub_port_connect_change drivers/usb/core/hub.c:5706 [inline]
port_event drivers/usb/core/hub.c:5870 [inline]
hub_event+0x1cf5/0x4a20 drivers/usb/core/hub.c:5952
process_one_work kernel/workqueue.c:3263 [inline]
process_scheduled_works+0xae1/0x17b0 kernel/workqueue.c:3346
worker_thread+0x8a0/0xda0 kernel/workqueue.c:3427
kthread+0x711/0x8a0 kernel/kthread.c:463
ret_from_fork+0x47c/0x820 arch/x86/kernel/process.c:158
ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:245