INFO: task syz.1.320:7303 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.1.320 state:D stack:27960 pid:7303 tgid:7301 ppid:5806 task_flags:0x400040 flags:0x00080002
Call Trace:
context_switch kernel/sched/core.c:5298 [inline]
__schedule+0xfee/0x6120 kernel/sched/core.c:6911
__schedule_loop kernel/sched/core.c:6993 [inline]
schedule+0xdd/0x390 kernel/sched/core.c:7008
schedule_preempt_disabled+0x13/0x30 kernel/sched/core.c:7065
__mutex_lock_common kernel/locking/mutex.c:692 [inline]
__mutex_lock+0xc9a/0x1b90 kernel/locking/mutex.c:776
sync_bdevs+0x153/0x480 block/bdev.c:1296
ksys_sync+0xb0/0xf0 fs/sync.c:105
__do_sys_sync+0xe/0x20 fs/sync.c:111
do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline]
do_syscall_64+0x10b/0xf80 arch/x86/entry/syscall_64.c:94
entry_SYSCALL_64_after_hwframe+0x77/0x7f
RIP: 0033:0x7f495139c819
RSP: 002b:00007f49521d0028 EFLAGS: 00000246 ORIG_RAX: 00000000000000a2
RAX: ffffffffffffffda RBX: 00007f4951616090 RCX: 00007f495139c819
RDX: 0000000000000000 RSI: 0000000000000000 RDI: 0000000000000000
RBP: 00007f4951616090 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000
R13: 00007f4951616128 R14: 00007f4951616090 R15: 00007fffa83f77b8
INFO: task syz.1.320:7306 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.1.320 state:D stack:27336 pid:7306 tgid:7301 ppid:5806 task_flags:0x400040 flags:0x00080002
Call Trace:
context_switch kernel/sched/core.c:5298 [inline]
__schedule+0xfee/0x6120 kernel/sched/core.c:6911
__schedule_loop kernel/sched/core.c:6993 [inline]
schedule+0xdd/0x390 kernel/sched/core.c:7008
schedule_preempt_disabled+0x13/0x30 kernel/sched/core.c:7065
__mutex_lock_common kernel/locking/mutex.c:692 [inline]
__mutex_lock+0xc9a/0x1b90 kernel/locking/mutex.c:776
sync_bdevs+0x153/0x480 block/bdev.c:1296
ksys_sync+0xb0/0xf0 fs/sync.c:105
__do_sys_sync+0xe/0x20 fs/sync.c:111
do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline]
do_syscall_64+0x10b/0xf80 arch/x86/entry/syscall_64.c:94
entry_SYSCALL_64_after_hwframe+0x77/0x7f
RIP: 0033:0x7f495139c819
RSP: 002b:00007f49521af028 EFLAGS: 00000246 ORIG_RAX: 00000000000000a2
RAX: ffffffffffffffda RBX: 00007f4951616180 RCX: 00007f495139c819
RDX: 0000000000000000 RSI: 0000000000000000 RDI: 0000000000000000
RBP: 00007f4951616180 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000
R13: 00007f4951616218 R14: 00007f4951616180 R15: 00007fffa83f77b8
Showing all locks held in the system:
3 locks held by kworker/0:0/9:
3 locks held by kworker/0:1/10:
#0: ffff88813fe67148 ((wq_completion)events){+.+.}-{0:0}, at: process_one_work+0x1310/0x19a0 kernel/workqueue.c:3263
#1: ffffc900000f7d08 (free_ipc_work){+.+.}-{0:0}, at: process_one_work+0x988/0x19a0 kernel/workqueue.c:3264
#2: ffffffff8e7f2678 (rcu_state.exp_mutex){+.+.}-{4:4}, at: exp_funnel_lock+0x19e/0x3c0 kernel/rcu/tree_exp.h:343
1 lock held by khungtaskd/31:
#0: ffffffff8e7e6b20 (rcu_read_lock){....}-{1:3}, at: rcu_lock_acquire include/linux/rcupdate.h:309 [inline]
#0: ffffffff8e7e6b20 (rcu_read_lock){....}-{1:3}, at: rcu_read_lock include/linux/rcupdate.h:847 [inline]
#0: ffffffff8e7e6b20 (rcu_read_lock){....}-{1:3}, at: debug_show_all_locks+0x3d/0x184 kernel/locking/lockdep.c:6775
5 locks held by kworker/1:2/792:
#0: ffff88802368dd48 ((wq_completion)usb_hub_wq){+.+.}-{0:0}, at: process_one_work+0x1310/0x19a0 kernel/workqueue.c:3263
#1: ffffc90004047d08 ((work_completion)(&hub->events)){+.+.}-{0:0}, at: process_one_work+0x988/0x19a0 kernel/workqueue.c:3264
#2: ffff88802bb941e0 (&dev->mutex){....}-{4:4}, at: device_lock include/linux/device.h:949 [inline]
#2: ffff88802bb941e0 (&dev->mutex){....}-{4:4}, at: hub_event+0x1bd/0x4af0 drivers/usb/core/hub.c:5899
#3: ffff88802bbcc560 (&port_dev->status_lock){+.+.}-{4:4}, at: usb_lock_port drivers/usb/core/hub.c:3252 [inline]
#3: ffff88802bbcc560 (&port_dev->status_lock){+.+.}-{4:4}, at: hub_port_connect drivers/usb/core/hub.c:5464 [inline]
#3: ffff88802bbcc560 (&port_dev->status_lock){+.+.}-{4:4}, at: hub_port_connect_change drivers/usb/core/hub.c:5707 [inline]
#3: ffff88802bbcc560 (&port_dev->status_lock){+.+.}-{4:4}, at: port_event drivers/usb/core/hub.c:5871 [inline]
#3: ffff88802bbcc560 (&port_dev->status_lock){+.+.}-{4:4}, at: hub_event+0x2bd2/0x4af0 drivers/usb/core/hub.c:5953
#4: ffff88802ba3b668 (hcd->address0_mutex){+.+.}-{4:4}, at: hub_port_connect drivers/usb/core/hub.c:5465 [inline]
#4: ffff88802ba3b668 (hcd->address0_mutex){+.+.}-{4:4}, at: hub_port_connect_change drivers/usb/core/hub.c:5707 [inline]
#4: ffff88802ba3b668 (hcd->address0_mutex){+.+.}-{4:4}, at: port_event drivers/usb/core/hub.c:5871 [inline]
#4: ffff88802ba3b668 (hcd->address0_mutex){+.+.}-{4:4}, at: hub_event+0x2bfb/0x4af0 drivers/usb/core/hub.c:5953
6 locks held by kworker/0:2/1615:
#0: ffff88802368dd48 ((wq_completion)usb_hub_wq){+.+.}-{0:0}, at: process_one_work+0x1310/0x19a0 kernel/workqueue.c:3263
#1: ffffc90005e6fd08 ((work_completion)(&hub->events)){+.+.}-{0:0}, at: process_one_work+0x988/0x19a0 kernel/workqueue.c:3264
#2: ffff88802ba861e0 (&dev->mutex){....}-{4:4}, at: device_lock include/linux/device.h:949 [inline]
#2: ffff88802ba861e0 (&dev->mutex){....}-{4:4}, at: hub_event+0x1bd/0x4af0 drivers/usb/core/hub.c:5899
#3: ffff8880562601e0 (&dev->mutex){....}-{4:4}, at: device_lock include/linux/device.h:949 [inline]
#3: ffff8880562601e0 (&dev->mutex){....}-{4:4}, at: usb_disconnect+0x10a/0x9a0 drivers/usb/core/hub.c:2336
#4: ffff8880361411a8 (&dev->mutex){....}-{4:4}, at: device_lock include/linux/device.h:949 [inline]
#4: ffff8880361411a8 (&dev->mutex){....}-{4:4}, at: __device_driver_lock drivers/base/dd.c:1154 [inline]
#4: ffff8880361411a8 (&dev->mutex){....}-{4:4}, at: device_release_driver_internal+0xb2/0x620 drivers/base/dd.c:1352
#5: ffffffff8fe21028 (input_mutex){+.+.}-{4:4}, at: class_mutex_constructor include/linux/mutex.h:253 [inline]
#5: ffffffff8fe21028 (input_mutex){+.+.}-{4:4}, at: __input_unregister_device+0x184/0x4d0 drivers/input/input.c:2187
1 lock held by acpid/5164:
#0: ffffffff8e7f2678 (rcu_state.exp_mutex){+.+.}-{4:4}, at: exp_funnel_lock+0x19e/0x3c0 kernel/rcu/tree_exp.h:343
1 lock held by klogd/5168:
#0: ffff8880b843b220 (&rq->__lock){-.-.}-{2:2}, at: raw_spin_rq_lock_nested+0x2c/0x140 kernel/sched/core.c:647
2 locks held by getty/5566:
#0: ffff8880398b10a0 (&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+0x419/0x1500 drivers/tty/n_tty.c:2211
5 locks held by kworker/0:3/5807:
#0: ffff88802368dd48 ((wq_completion)usb_hub_wq){+.+.}-{0:0}, at: process_one_work+0x1310/0x19a0 kernel/workqueue.c:3263
#1: ffffc90003bd7d08 ((work_completion)(&hub->events)){+.+.}-{0:0}, at: process_one_work+0x988/0x19a0 kernel/workqueue.c:3264
#2: ffff88802b93a1e0 (&dev->mutex){....}-{4:4}, at: device_lock include/linux/device.h:949 [inline]
#2: ffff88802b93a1e0 (&dev->mutex){....}-{4:4}, at: hub_event+0x1bd/0x4af0 drivers/usb/core/hub.c:5899
#3: ffff88802b983560 (&port_dev->status_lock){+.+.}-{4:4}, at: usb_lock_port drivers/usb/core/hub.c:3252 [inline]
#3: ffff88802b983560 (&port_dev->status_lock){+.+.}-{4:4}, at: hub_port_connect drivers/usb/core/hub.c:5464 [inline]
#3: ffff88802b983560 (&port_dev->status_lock){+.+.}-{4:4}, at: hub_port_connect_change drivers/usb/core/hub.c:5707 [inline]
#3: ffff88802b983560 (&port_dev->status_lock){+.+.}-{4:4}, at: port_event drivers/usb/core/hub.c:5871 [inline]
#3: ffff88802b983560 (&port_dev->status_lock){+.+.}-{4:4}, at: hub_event+0x2bd2/0x4af0 drivers/usb/core/hub.c:5953
#4: ffff88802b84d668 (hcd->address0_mutex){+.+.}-{4:4}, at: hub_port_connect drivers/usb/core/hub.c:5465 [inline]
#4: ffff88802b84d668 (hcd->address0_mutex){+.+.}-{4:4}, at: hub_port_connect_change drivers/usb/core/hub.c:5707 [inline]
#4: ffff88802b84d668 (hcd->address0_mutex){+.+.}-{4:4}, at: port_event drivers/usb/core/hub.c:5871 [inline]
#4: ffff88802b84d668 (hcd->address0_mutex){+.+.}-{4:4}, at: hub_event+0x2bfb/0x4af0 drivers/usb/core/hub.c:5953
1 lock held by udevd/6066:
#0: ffff8880282c3358 (&disk->open_mutex){+.+.}-{4:4}, at: bdev_open+0x41a/0xe40 block/bdev.c:953
1 lock held by syz.1.320/7303:
#0: ffff8880282c3358 (&disk->open_mutex){+.+.}-{4:4}, at: sync_bdevs+0x153/0x480 block/bdev.c:1296
1 lock held by syz.1.320/7306:
#0: ffff8880282c3358 (&disk->open_mutex){+.+.}-{4:4}, at: sync_bdevs+0x153/0x480 block/bdev.c:1296
3 locks held by syz.4.462/7857:
#0: ffff88805eb54ec0 (&hdev->req_lock){+.+.}-{4:4}, at: hci_dev_do_close+0x26/0xb0 net/bluetooth/hci_core.c:500
#1: ffff88805eb540c0 (&hdev->lock){+.+.}-{4:4}, at: hci_dev_close_sync+0x35c/0x1240 net/bluetooth/hci_sync.c:5356
#2: ffffffff908b25c8 (hci_cb_list_lock){+.+.}-{4:4}, at: hci_disconn_cfm include/net/bluetooth/hci_core.h:2151 [inline]
#2: ffffffff908b25c8 (hci_cb_list_lock){+.+.}-{4:4}, at: hci_conn_hash_flush+0xbb/0x280 net/bluetooth/hci_conn.c:2650
3 locks held by syz.6.884/9601:
#0: ffff88807a3c4ec0 (&hdev->req_lock){+.+.}-{4:4}, at: hci_dev_do_close+0x26/0xb0 net/bluetooth/hci_core.c:500
#1: ffff88807a3c40c0 (&hdev->lock){+.+.}-{4:4}, at: hci_dev_close_sync+0x35c/0x1240 net/bluetooth/hci_sync.c:5356
#2: ffffffff908b25c8 (hci_cb_list_lock){+.+.}-{4:4}, at: hci_disconn_cfm include/net/bluetooth/hci_core.h:2151 [inline]
#2: ffffffff908b25c8 (hci_cb_list_lock){+.+.}-{4:4}, at: hci_conn_hash_flush+0xbb/0x280 net/bluetooth/hci_conn.c:2650
3 locks held by syz.2.885/9603:
#0: ffff888034bb4ec0 (&hdev->req_lock){+.+.}-{4:4}, at: hci_dev_do_close+0x26/0xb0 net/bluetooth/hci_core.c:500
#1: ffff888034bb40c0 (&hdev->lock){+.+.}-{4:4}, at: hci_dev_close_sync+0x35c/0x1240 net/bluetooth/hci_sync.c:5356
#2: ffffffff908b25c8 (hci_cb_list_lock){+.+.}-{4:4}, at: hci_disconn_cfm include/net/bluetooth/hci_core.h:2151 [inline]
#2: ffffffff908b25c8 (hci_cb_list_lock){+.+.}-{4:4}, at: hci_conn_hash_flush+0xbb/0x280 net/bluetooth/hci_conn.c:2650
3 locks held by syz.3.887/9609:
#0: ffff88805eb44ec0 (&hdev->req_lock){+.+.}-{4:4}, at: hci_dev_do_close+0x26/0xb0 net/bluetooth/hci_core.c:500
#1: ffff88805eb440c0 (&hdev->lock){+.+.}-{4:4}, at: hci_dev_close_sync+0x35c/0x1240 net/bluetooth/hci_sync.c:5356
#2: ffffffff908b25c8 (hci_cb_list_lock){+.+.}-{4:4}, at: hci_disconn_cfm include/net/bluetooth/hci_core.h:2151 [inline]
#2: ffffffff908b25c8 (hci_cb_list_lock){+.+.}-{4:4}, at: hci_conn_hash_flush+0xbb/0x280 net/bluetooth/hci_conn.c:2650
4 locks held by syz.5.888/9616:
#0: ffff8880538b4ec0 (&hdev->req_lock){+.+.}-{4:4}, at: hci_dev_do_close+0x26/0xb0 net/bluetooth/hci_core.c:500
#1: ffff8880538b40c0 (&hdev->lock){+.+.}-{4:4}, at: hci_dev_close_sync+0x35c/0x1240 net/bluetooth/hci_sync.c:5356
#2: ffffffff908b25c8 (hci_cb_list_lock){+.+.}-{4:4}, at: hci_disconn_cfm include/net/bluetooth/hci_core.h:2151 [inline]
#2: ffffffff908b25c8 (hci_cb_list_lock){+.+.}-{4:4}, at: hci_conn_hash_flush+0xbb/0x280 net/bluetooth/hci_conn.c:2650
#3: ffff888035d50b00 (&conn->lock#2){+.+.}-{4:4}, at: l2cap_conn_del+0x95/0x710 net/bluetooth/l2cap_core.c:1777
=============================================
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 03/18/2026
Call Trace:
__dump_stack lib/dump_stack.c:94 [inline]
dump_stack_lvl+0x100/0x190 lib/dump_stack.c:120
nmi_cpu_backtrace.cold+0x12d/0x151 lib/nmi_backtrace.c:113
nmi_trigger_cpumask_backtrace+0x1d7/0x230 lib/nmi_backtrace.c:62
trigger_all_cpu_backtrace include/linux/nmi.h:161 [inline]
__sys_info lib/sys_info.c:157 [inline]
sys_info+0x141/0x190 lib/sys_info.c:165
check_hung_uninterruptible_tasks kernel/hung_task.c:346 [inline]
watchdog+0xd25/0x1050 kernel/hung_task.c:515
kthread+0x370/0x450 kernel/kthread.c:436
ret_from_fork+0x72b/0xd50 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: 0 Comm: swapper/0 Tainted: G L syzkaller #0 PREEMPT(full)
Tainted: [L]=SOFTLOCKUP
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 03/18/2026
RIP: 0010:arch_atomic_read arch/x86/include/asm/atomic.h:23 [inline]
RIP: 0010:raw_atomic_read include/linux/atomic/atomic-arch-fallback.h:457 [inline]
RIP: 0010:rcu_is_watching_curr_cpu include/linux/context_tracking.h:128 [inline]
RIP: 0010:rcu_is_watching+0x60/0xc0 kernel/rcu/tree.c:752
Code: 48 89 fa 48 c1 ea 03 80 3c 02 00 75 5c 48 03 1c ed e0 48 13 8e 48 b8 00 00 00 00 00 fc ff df 48 89 da 48 c1 ea 03 0f b6 14 02 <48> 89 d8 83 e0 07 83 c0 03 38 d0 7c 04 84 d2 75 24 8b 03 c1 e8 02
RSP: 0018:ffffc90000007b20 EFLAGS: 00000802
RAX: dffffc0000000000 RBX: ffff8880b8433ce8 RCX: ffffffff81f49602
RDX: 0000000000000000 RSI: ffffffff8c1b6220 RDI: ffffffff8e1348e0
RBP: 0000000000000000 R08: 0000000000000001 R09: 0000000000000000
R10: 0000000000000001 R11: 0000000000000000 R12: 0000000000000001
R13: 0000000000000005 R14: 0000000000000004 R15: ffff8880b8428740
FS: 0000000000000000(0000) GS:ffff88812432b000(0000) knlGS:0000000000000000
CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 000000110c398d5b CR3: 0000000056f74000 CR4: 00000000003526f0
Call Trace:
trace_hrtimer_start include/trace/events/timer.h:222 [inline]
debug_activate kernel/time/hrtimer.c:486 [inline]
enqueue_hrtimer+0x31b/0x3e0 kernel/time/hrtimer.c:1089
__hrtimer_start_range_ns kernel/time/hrtimer.c:1271 [inline]
hrtimer_start_range_ns+0xa74/0xfd0 kernel/time/hrtimer.c:1330
hrtimer_start include/linux/hrtimer.h:244 [inline]
dummy_timer+0x216f/0x36c0 drivers/usb/gadget/udc/dummy_hcd.c:2018
__run_hrtimer kernel/time/hrtimer.c:1785 [inline]
__hrtimer_run_queues+0x50e/0xa70 kernel/time/hrtimer.c:1849
hrtimer_run_softirq+0x17d/0x350 kernel/time/hrtimer.c:1866
handle_softirqs+0x1eb/0x9e0 kernel/softirq.c:622
__do_softirq kernel/softirq.c:656 [inline]
invoke_softirq kernel/softirq.c:496 [inline]
__irq_exit_rcu+0xef/0x150 kernel/softirq.c:723
irq_exit_rcu+0x9/0x30 kernel/softirq.c:739
instr_sysvec_apic_timer_interrupt arch/x86/kernel/apic/apic.c:1056 [inline]
sysvec_apic_timer_interrupt+0xa3/0xc0 arch/x86/kernel/apic/apic.c:1056
asm_sysvec_apic_timer_interrupt+0x1a/0x20 arch/x86/include/asm/idtentry.h:697
RIP: 0010:pv_native_safe_halt+0xf/0x20 arch/x86/kernel/paravirt.c:63
Code: f7 80 02 c3 cc cc cc cc 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 33 1f 19 00 fb f4 cc 35 03 00 66 2e 0f 1f 84 00 00 00 00 00 66 90 90 90 90 90 90
RSP: 0018:ffffffff8e407e00 EFLAGS: 00000242
RAX: 0000000000dbec4f RBX: ffffffff8e4975c0 RCX: ffffffff8b926d45
RDX: 0000000000000000 RSI: ffffffff8de8208a RDI: ffffffff8c1b62a0
RBP: 0000000000000000 R08: 0000000000000001 R09: ffffed101708679d
R10: ffff8880b8433ceb R11: 0000000000000000 R12: 0000000000000000
R13: fffffbfff1c92eb8 R14: 0000000000000000 R15: ffffffff90da2a10
arch_safe_halt arch/x86/include/asm/paravirt.h:73 [inline]
default_idle+0x9/0x10 arch/x86/kernel/process.c:767
default_idle_call+0x6c/0xb0 kernel/sched/idle.c:122
cpuidle_idle_call kernel/sched/idle.c:199 [inline]
do_idle+0x464/0x590 kernel/sched/idle.c:352
cpu_startup_entry+0x4f/0x60 kernel/sched/idle.c:451
rest_init+0x251/0x260 init/main.c:761
start_kernel+0x47f/0x480 init/main.c:1218
x86_64_start_reservations+0x24/0x30 arch/x86/kernel/head64.c:310
x86_64_start_kernel+0x12b/0x130 arch/x86/kernel/head64.c:291
common_startup_64+0x13e/0x148