INFO: task poweroff:15437 blocked for more than 143 seconds. Not tainted syzkaller #0 "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message. task:poweroff state:D stack:24488 pid:15437 tgid:15437 ppid:5180 task_flags:0x400000 flags:0x00080001 Call Trace: context_switch kernel/sched/core.c:5325 [inline] __schedule+0x1798/0x4cc0 kernel/sched/core.c:6929 __schedule_loop kernel/sched/core.c:7011 [inline] schedule+0x165/0x360 kernel/sched/core.c:7026 schedule_preempt_disabled+0x13/0x30 kernel/sched/core.c:7083 __mutex_lock_common kernel/locking/mutex.c:676 [inline] __mutex_lock+0x7e6/0x1350 kernel/locking/mutex.c:760 sync_bdevs+0x1ac/0x340 block/bdev.c:1288 ksys_sync+0xb9/0x150 fs/sync.c:105 __ia32_sys_sync+0xe/0x20 fs/sync.c:113 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: 0033:0x7f73cfe40f37 RSP: 002b:00007ffe00bdead8 EFLAGS: 00000246 ORIG_RAX: 00000000000000a2 RAX: ffffffffffffffda RBX: 0000000000000001 RCX: 00007f73cfe40f37 RDX: ffffffffffffff88 RSI: 00007f73cffd9e51 RDI: 00000000ffffff9c RBP: 0000000000000000 R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000 R13: 00007ffe00bdec38 R14: 00007f73d0023000 R15: 000056071e473d98 Showing all locks held in the system: 1 lock held by khungtaskd/31: #0: ffffffff8e13d2e0 (rcu_read_lock){....}-{1:3}, at: rcu_lock_acquire include/linux/rcupdate.h:331 [inline] #0: ffffffff8e13d2e0 (rcu_read_lock){....}-{1:3}, at: rcu_read_lock include/linux/rcupdate.h:867 [inline] #0: ffffffff8e13d2e0 (rcu_read_lock){....}-{1:3}, at: debug_show_all_locks+0x2e/0x180 kernel/locking/lockdep.c:6775 2 locks held by getty/5591: #0: ffff88814ce5a0a0 (&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 6 locks held by kworker/1:3/5822: #0: ffff88801faed148 ((wq_completion)usb_hub_wq){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:3238 [inline] #0: ffff88801faed148 ((wq_completion)usb_hub_wq){+.+.}-{0:0}, at: process_scheduled_works+0x9b4/0x17b0 kernel/workqueue.c:3346 #1: ffffc90003e6fba0 ((work_completion)(&hub->events)){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:3239 [inline] #1: ffffc90003e6fba0 ((work_completion)(&hub->events)){+.+.}-{0:0}, at: process_scheduled_works+0x9ef/0x17b0 kernel/workqueue.c:3346 #2: ffff888144bec198 (&dev->mutex){....}-{4:4}, at: device_lock include/linux/device.h:914 [inline] #2: ffff888144bec198 (&dev->mutex){....}-{4:4}, at: hub_event+0x184/0x4a20 drivers/usb/core/hub.c:5893 #3: ffff88807cba3198 (&dev->mutex){....}-{4:4}, at: device_lock include/linux/device.h:914 [inline] #3: ffff88807cba3198 (&dev->mutex){....}-{4:4}, at: __device_attach+0x88/0x400 drivers/base/dd.c:1006 #4: ffff8881436ac160 (&dev->mutex){....}-{4:4}, at: device_lock include/linux/device.h:914 [inline] #4: ffff8881436ac160 (&dev->mutex){....}-{4:4}, at: __device_attach+0x88/0x400 drivers/base/dd.c:1006 #5: ffffffff8f452b48 (register_mutex#6){+.+.}-{4:4}, at: class_mutex_constructor include/linux/mutex.h:228 [inline] #5: ffffffff8f452b48 (register_mutex#6){+.+.}-{4:4}, at: usb_audio_probe+0x7f8/0x22f0 sound/usb/card.c:950 2 locks held by kworker/1:8/5939: 1 lock held by udevd/9847: #0: ffff88802529d358 (&disk->open_mutex){+.+.}-{4:4}, at: bdev_open+0xe0/0xd30 block/bdev.c:945 4 locks held by udevd/9855: #0: ffff8880392038b8 (&p->lock){+.+.}-{4:4}, at: seq_read_iter+0xb7/0xe20 fs/seq_file.c:182 #1: ffff88805d95d088 (&of->mutex#2){+.+.}-{4:4}, at: kernfs_seq_start+0x5c/0x420 fs/kernfs/file.c:172 #2: ffff88805fbbdb48 (kn->active#19){++++}-{0:0}, at: kernfs_get_active_of fs/kernfs/file.c:80 [inline] #2: ffff88805fbbdb48 (kn->active#19){++++}-{0:0}, at: kernfs_seq_start+0xb2/0x420 fs/kernfs/file.c:173 #3: ffff88807cba3198 (&dev->mutex){....}-{4:4}, at: device_lock_interruptible include/linux/device.h:919 [inline] #3: ffff88807cba3198 (&dev->mutex){....}-{4:4}, at: manufacturer_show+0x26/0xa0 drivers/usb/core/sysfs.c:142 1 lock held by poweroff/15437: #0: ffff88802529d358 (&disk->open_mutex){+.+.}-{4:4}, at: sync_bdevs+0x1ac/0x340 block/bdev.c:1288 1 lock held by syz.4.3740/18103: #0: ffffffff8e142c40 (rcu_state.barrier_mutex){+.+.}-{4:4}, at: rcu_barrier+0x4c/0x570 kernel/rcu/tree.c:3820 ============================================= NMI backtrace for cpu 1 CPU: 1 UID: 0 PID: 31 Comm: khungtaskd Not tainted syzkaller #0 PREEMPT(full) Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 10/02/2025 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:337 [inline] watchdog+0xfa9/0xff0 kernel/hung_task.c:500 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 1 to CPUs 0: NMI backtrace for cpu 0 CPU: 0 UID: 0 PID: 18109 Comm: syz.2.3736 Not tainted syzkaller #0 PREEMPT(full) Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 10/02/2025 RIP: 0010:update_min_vruntime kernel/sched/fair.c:774 [inline] RIP: 0010:update_curr+0x2ba/0x730 kernel/sched/fair.c:1229 Code: c5 70 48 89 e8 48 c1 e8 03 48 b9 00 00 00 00 00 fc ff df 80 3c 08 00 74 08 48 89 ef e8 0f bd 90 00 48 8b 6d 00 4d 85 ed 74 5f <49> 83 c5 30 4c 89 e8 48 c1 e8 03 48 b9 00 00 00 00 00 fc ff df 80 RSP: 0018:ffffc900001177c0 EFLAGS: 00000086 RAX: 1ffff1100482c98e RBX: ffff888024164c00 RCX: dffffc0000000000 RDX: 0000000000000000 RSI: ffffffff8d9df6dc RDI: ffffffff8bc0d6e0 RBP: 0000004e7876dc44 R08: ffffffff8f9dd677 R09: 1ffffffff1f3bace R10: dffffc0000000000 R11: fffffbfff1f3bacf R12: 1ffff110170c7426 R13: ffff888025501ec0 R14: 0000004e789abc5a R15: ffff8880b863a130 FS: 00007f334d98e6c0(0000) GS:ffff888125d22000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 00007f334d98cff0 CR3: 000000004c3b4000 CR4: 00000000003526f0 Call Trace: dequeue_entity kernel/sched/fair.c:5375 [inline] dequeue_entities+0x1b3/0x30b0 kernel/sched/fair.c:7066 dequeue_task_fair+0x20e/0x790 kernel/sched/fair.c:7165 block_task kernel/sched/core.c:2157 [inline] try_to_block_task kernel/sched/core.c:6553 [inline] __schedule+0x5f1/0x4cc0 kernel/sched/core.c:6864 __schedule_loop kernel/sched/core.c:7011 [inline] schedule+0x165/0x360 kernel/sched/core.c:7026 do_nanosleep+0x1c5/0x610 kernel/time/hrtimer.c:2116 hrtimer_nanosleep+0x169/0x360 kernel/time/hrtimer.c:2163 __do_sys_clock_nanosleep kernel/time/posix-timers.c:1398 [inline] __se_sys_clock_nanosleep+0x339/0x390 kernel/time/posix-timers.c:1375 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: 0033:0x7f334cbc1885 Code: 24 0c 89 3c 24 48 89 4c 24 18 e8 f6 54 ff ff 4c 8b 54 24 18 48 8b 54 24 10 41 89 c0 8b 74 24 0c 8b 3c 24 b8 e6 00 00 00 0f 05 <44> 89 c7 48 89 04 24 e8 4f 55 ff ff 48 8b 04 24 48 83 c4 28 f7 d8 RSP: 002b:00007f334d98bf50 EFLAGS: 00000293 ORIG_RAX: 00000000000000e6 RAX: ffffffffffffffda RBX: 0000000000000003 RCX: 00007f334cbc1885 RDX: 00007f334d98bf90 RSI: 0000000000000000 RDI: 0000000000000000 RBP: 0000000000000001 R08: 0000000000000000 R09: 0000000000000001 R10: 0000000000000000 R11: 0000000000000293 R12: 00007f334d98bfe8 R13: 0000000000000000 R14: 00007f334cde6180 R15: 00007ffe1bf9a9f8