INFO: task syz.3.185:6491 blocked for more than 143 seconds.
Not tainted syzkaller #0
"echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message.
task:syz.3.185 state:D stack:25608 pid:6491 tgid:6491 ppid:5862 task_flags:0x400040 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
bdev_release+0x1a9/0x650 block/bdev.c:1128
blkdev_release+0x15/0x20 block/fops.c:702
__fput+0x44c/0xa70 fs/file_table.c:468
task_work_run+0x1d4/0x260 kernel/task_work.c:227
resume_user_mode_work include/linux/resume_user_mode.h:50 [inline]
exit_to_user_mode_loop+0xec/0x130 kernel/entry/common.c:43
exit_to_user_mode_prepare include/linux/irq-entry-common.h:225 [inline]
syscall_exit_to_user_mode_work include/linux/entry-common.h:175 [inline]
syscall_exit_to_user_mode include/linux/entry-common.h:210 [inline]
do_syscall_64+0x2bd/0xfa0 arch/x86/entry/syscall_64.c:100
entry_SYSCALL_64_after_hwframe+0x77/0x7f
RIP: 0033:0x7f58adb8eba9
RSP: 002b:00007fffcd4ba9d8 EFLAGS: 00000246 ORIG_RAX: 00000000000001b4
RAX: 0000000000000000 RBX: 000000000001e524 RCX: 00007f58adb8eba9
RDX: 0000000000000000 RSI: 000000000000001e RDI: 0000000000000003
RBP: 00007f58addd7da0 R08: 0000000000000001 R09: 00000013cd4baccf
R10: 0000001b32020000 R11: 0000000000000246 R12: 00007f58addd5fac
R13: 00007f58addd5fa0 R14: ffffffffffffffff R15: 00007fffcd4baaf0
Showing all locks held in the system:
1 lock held by khungtaskd/31:
#0: ffffffff8e53c820 (rcu_read_lock){....}-{1:3}, at: rcu_lock_acquire include/linux/rcupdate.h:331 [inline]
#0: ffffffff8e53c820 (rcu_read_lock){....}-{1:3}, at: rcu_read_lock include/linux/rcupdate.h:841 [inline]
#0: ffffffff8e53c820 (rcu_read_lock){....}-{1:3}, at: debug_show_all_locks+0x2e/0x180 kernel/locking/lockdep.c:6775
6 locks held by kworker/1:2/937:
#0: ffff888144afed48 ((wq_completion)usb_hub_wq){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:3238 [inline]
#0: ffff888144afed48 ((wq_completion)usb_hub_wq){+.+.}-{0:0}, at: process_scheduled_works+0x9b4/0x17b0 kernel/workqueue.c:3346
#1:
ffffc90003abfba0
((work_completion)(&hub->events)){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:3239 [inline]
((work_completion)(&hub->events)){+.+.}-{0:0}, at: process_scheduled_works+0x9ef/0x17b0 kernel/workqueue.c:3346
#2: ffff888027e1a198 (&dev->mutex){....}-{4:4}, at: device_lock include/linux/device.h:914 [inline]
#2: ffff888027e1a198 (&dev->mutex){....}-{4:4}, at: hub_event+0x184/0x4a20 drivers/usb/core/hub.c:5898
#3: ffff88807cab1198 (&dev->mutex){....}-{4:4}, at: device_lock include/linux/device.h:914 [inline]
#3: ffff88807cab1198 (&dev->mutex){....}-{4:4}, at: __device_attach+0x88/0x400 drivers/base/dd.c:1006
#4: ffff88807dc30160 (&dev->mutex){....}-{4:4}, at: device_lock include/linux/device.h:914 [inline]
#4: ffff88807dc30160 (&dev->mutex){....}-{4:4}, at: __device_attach+0x88/0x400 drivers/base/dd.c:1006
#5: ffffffff8f8a9808 (register_mutex#6){+.+.}-{4:4}, at: class_mutex_constructor include/linux/mutex.h:228 [inline]
#5: ffffffff8f8a9808 (register_mutex#6){+.+.}-{4:4}, at: usb_audio_probe+0x390/0x1e40 sound/usb/card.c:903
3 locks held by kworker/u8:6/2138:
1 lock held by udevd/5231:
2 locks held by getty/5621:
#0: ffff88803031d0a0 (&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+0x43e/0x1400 drivers/tty/n_tty.c:2222
2 locks held by kworker/u9:5/5870:
#0: ffff8880259b9948 ((wq_completion)nbd3-recv){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:3238 [inline]
#0: ffff8880259b9948 ((wq_completion)nbd3-recv){+.+.}-{0:0}, at: process_scheduled_works+0x9b4/0x17b0 kernel/workqueue.c:3346
#1: ffffc90004057ba0 ((work_completion)(&args->work)){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:3239 [inline]
#1: ffffc90004057ba0 ((work_completion)(&args->work)){+.+.}-{0:0}, at: process_scheduled_works+0x9ef/0x17b0 kernel/workqueue.c:3346
1 lock held by udevd/5874:
#0: ffff8880259b3358 (&disk->open_mutex){+.+.}-{4:4}, at: bdev_open+0xe0/0xd30 block/bdev.c:945
1 lock held by syz.3.185/6491:
#0: ffff8880259b3358 (&disk->open_mutex){+.+.}-{4:4}, at: bdev_release+0x1a9/0x650 block/bdev.c:1128
4 locks held by udevd/6674:
#0: ffff8880767e80a0 (&p->lock){+.+.}-{4:4}, at: seq_read_iter+0xb7/0xe20 fs/seq_file.c:182
#1: ffff888145b70888 (&of->mutex#2){+.+.}-{4:4}, at: kernfs_seq_start+0x5c/0x420 fs/kernfs/file.c:172
#2: ffff88804bc1de18 (kn->active#19){++++}-{0:0}, at: kernfs_get_active_of fs/kernfs/file.c:80 [inline]
#2: ffff88804bc1de18 (kn->active#19){++++}-{0:0}, at: kernfs_seq_start+0xb2/0x420 fs/kernfs/file.c:173
#3: ffff88807cab1198 (&dev->mutex){....}-{4:4}, at: device_lock_interruptible include/linux/device.h:919 [inline]
#3: ffff88807cab1198 (&dev->mutex){....}-{4:4}, at: manufacturer_show+0x26/0xa0 drivers/usb/core/sysfs.c:142
1 lock held by udevd/7740:
#0: ffff888025844358 (&disk->open_mutex){+.+.}-{4:4}, at: bdev_open+0xe0/0xd30 block/bdev.c:945
=============================================
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 08/18/2025
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+0x4bc/0x870 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: 937 Comm: kworker/1:2 Not tainted syzkaller #0 PREEMPT(full)
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 08/18/2025
Workqueue: usb_hub_wq hub_event
RIP: 0010:avg_vruntime kernel/sched/fair.c:660 [inline]
RIP: 0010:place_entity+0xb1/0x580 kernel/sched/fair.c:5130
Code: 00 4c 89 7c 24 28 4d 8b 27 4d 85 ed 0f 84 b9 00 00 00 4d 8d 7d 50 4c 89 f8 48 c1 e8 03 42 0f b6 04 30 84 c0 0f 85 6a 04 00 00 <41> 80 3f 00 0f 84 97 00 00 00 4c 89 e8 48 c1 e8 03 42 80 3c 30 00
RSP: 0018:ffffc90000a08a28 EFLAGS: 00000046
RAX: 0000000000000000 RBX: ffff88805d679000 RCX: 000000000000b719
RDX: 0000000000000000 RSI: ffff88805d679000 RDI: ffff8880b873a060
RBP: ffff8880b873a040 R08: ffffffff8fe53a37 R09: 1ffffffff1fca746
R10: dffffc0000000000 R11: fffffbfff1fca747 R12: 0000000000000c00
R13: ffff888025c60080 R14: dffffc0000000000 R15: ffff888025c600d0
FS: 0000000000000000(0000) GS:ffff8881258a7000(0000) knlGS:0000000000000000
CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 0000001b32e22ff8 CR3: 000000007e8c6000 CR4: 00000000003526f0
DR0: ffffffffffffffff DR1: 0000000000000047 DR2: 0000000000000005
DR3: 0000000000000000 DR6: 00000000ffff0ff0 DR7: 0000000000000400
Call Trace:
reweight_entity+0x530/0x8a0 kernel/sched/fair.c:3806
enqueue_task_fair+0x1724/0x2430 kernel/sched/fair.c:6967
enqueue_task+0x75/0x420 kernel/sched/core.c:2090
activate_task kernel/sched/core.c:2132 [inline]
ttwu_do_activate+0x1f3/0x870 kernel/sched/core.c:3741
ttwu_queue kernel/sched/core.c:4004 [inline]
try_to_wake_up+0x721/0x12b0 kernel/sched/core.c:4328
hrtimer_wakeup+0x4e/0x60 kernel/time/hrtimer.c:2013
__run_hrtimer kernel/time/hrtimer.c:1777 [inline]
__hrtimer_run_queues+0x52c/0xc60 kernel/time/hrtimer.c:1841
hrtimer_interrupt+0x45b/0xaa0 kernel/time/hrtimer.c:1903
local_apic_timer_interrupt arch/x86/kernel/apic/apic.c:1041 [inline]
__sysvec_apic_timer_interrupt+0x10b/0x410 arch/x86/kernel/apic/apic.c:1058
instr_sysvec_apic_timer_interrupt arch/x86/kernel/apic/apic.c:1052 [inline]
sysvec_apic_timer_interrupt+0xa1/0xc0 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 72 9b 1f 00 fb eb 44 e8 6a 9b 1f 00 e8 15 12 eb 09 4d 85 f6 74 94 e8 5b 9b 1f 00 fb 48 c7 c7 60 08 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:ffffc90003abf2a0 EFLAGS: 00000283
RAX: ffffffff81a07015 RBX: ffffffff81a06e6e RCX: 0000000000100000
RDX: ffffc90016877000 RSI: 000000000001289d RDI: ffffffff8e530860
RBP: ffffc90003abf3b0 R08: ffffffff8fe53a37 R09: 1ffffffff1fca746
R10: dffffc0000000000 R11: fffffbfff1fca747 R12: 0000000000000000
R13: 0000000000000029 R14: 0000000000000200 R15: 1ffff92000757e58
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+0x4bc/0x870 arch/x86/kernel/process.c:158
ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:245