INFO: task syz.1.4578:22691 blocked for more than 143 seconds. Not tainted syzkaller #0 "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message. task:syz.1.4578 state:D stack:26792 pid:22691 tgid:22690 ppid:21903 task_flags:0x400140 flags:0x00080002 Call Trace: context_switch kernel/sched/core.c:5254 [inline] __schedule+0x17c4/0x4d60 kernel/sched/core.c:6862 __schedule_loop kernel/sched/core.c:6944 [inline] schedule+0x165/0x360 kernel/sched/core.c:6959 schedule_preempt_disabled+0x13/0x30 kernel/sched/core.c:7016 __mutex_lock_common kernel/locking/mutex.c:676 [inline] __mutex_lock+0x7e6/0x1350 kernel/locking/mutex.c:760 bdev_open+0xe0/0xd30 block/bdev.c:945 bdev_file_open_by_dev+0x1be/0x240 block/bdev.c:1059 setup_bdev_super+0x5a/0x5b0 fs/super.c:1610 get_tree_bdev_flags+0x366/0x4d0 fs/super.c:1690 vfs_get_tree+0x92/0x2b0 fs/super.c:1752 fc_mount fs/namespace.c:1198 [inline] do_new_mount_fc fs/namespace.c:3641 [inline] do_new_mount+0x302/0xa10 fs/namespace.c:3717 do_mount fs/namespace.c:4040 [inline] __do_sys_mount fs/namespace.c:4228 [inline] __se_sys_mount+0x313/0x410 fs/namespace.c:4205 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: 0033:0x7eff7618efc9 RSP: 002b:00007eff77003038 EFLAGS: 00000246 ORIG_RAX: 00000000000000a5 RAX: ffffffffffffffda RBX: 00007eff763e5fa0 RCX: 00007eff7618efc9 RDX: 0000200000000000 RSI: 0000200000000100 RDI: 0000200000000040 RBP: 00007eff76211f91 R08: 0000000000000000 R09: 0000000000000000 R10: 0000000001000080 R11: 0000000000000246 R12: 0000000000000000 R13: 00007eff763e6038 R14: 00007eff763e5fa0 R15: 00007ffd9b8f4b68 Showing all locks held in the system: 1 lock held by khungtaskd/31: #0: ffffffff8e33d960 (rcu_read_lock){....}-{1:3}, at: rcu_lock_acquire include/linux/rcupdate.h:331 [inline] #0: ffffffff8e33d960 (rcu_read_lock){....}-{1:3}, at: rcu_read_lock include/linux/rcupdate.h:867 [inline] #0: ffffffff8e33d960 (rcu_read_lock){....}-{1:3}, at: debug_show_all_locks+0x2e/0x180 kernel/locking/lockdep.c:6775 2 locks held by getty/5580: #0: ffff8880307560a0 (&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 1 lock held by udevd/15344: #0: ffff88802582b358 (&disk->open_mutex){+.+.}-{4:4}, at: bdev_open+0xe0/0xd30 block/bdev.c:945 1 lock held by udevd/15448: #0: ffff88802586b358 (&disk->open_mutex){+.+.}-{4:4}, at: bdev_open+0xe0/0xd30 block/bdev.c:945 4 locks held by udevd/15449: #0: ffff8880b873a018 (&rq->__lock){-.-.}-{2:2}, at: raw_spin_rq_lock_nested+0x2a/0x140 kernel/sched/core.c:638 #1: ffff8880b8724048 (psi_seq){-.-.}-{0:0}, at: psi_task_switch+0x53/0x880 kernel/sched/psi.c:933 #2: ffff8880b8724048 (psi_seq){-.-.}-{0:0}, at: psi_task_switch+0x53/0x880 kernel/sched/psi.c:933 #3: ffff88805dea2ca8 (&ep->wq){....}-{3:3}, at: __wake_up_common_lock+0x2f/0x1f0 kernel/sched/wait.c:124 4 locks held by kworker/0:3/20208: #0: ffff88823be18148 ((wq_completion)usb_hub_wq){+.+.}-{0:0}, at: process_one_work+0x841/0x15d0 kernel/workqueue.c:3242 #1: ffffc9000cb3fba0 ((work_completion)(&hub->events)){+.+.}-{0:0}, at: process_one_work+0x868/0x15d0 kernel/workqueue.c:3243 #2: ffff888143b30198 (&dev->mutex){....}-{4:4}, at: device_lock include/linux/device.h:914 [inline] #2: ffff888143b30198 (&dev->mutex){....}-{4:4}, at: hub_event+0x187/0x4ef0 drivers/usb/core/hub.c:5899 #3: ffff8880361f8198 (&dev->mutex){....}-{4:4}, at: device_lock include/linux/device.h:914 [inline] #3: ffff8880361f8198 (&dev->mutex){....}-{4:4}, at: __device_attach+0x88/0x430 drivers/base/dd.c:1006 2 locks held by syz.1.4578/22691: #0: ffff88806b29e0e0 (&type->s_umount_key#100/1){+.+.}-{4:4}, at: alloc_super+0x1bb/0x960 fs/super.c:344 #1: ffff88802586b358 (&disk->open_mutex){+.+.}-{4:4}, at: bdev_open+0xe0/0xd30 block/bdev.c:945 ============================================= 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: 20208 Comm: kworker/0:3 Not tainted syzkaller #0 PREEMPT(full) Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 10/02/2025 Workqueue: usb_hub_wq hub_event RIP: 0010:idle_cpu kernel/sched/syscalls.c:185 [inline] RIP: 0010:available_idle_cpu+0x6c/0x170 kernel/sched/syscalls.c:205 Code: 8b 06 4c 8d b0 00 e0 b9 92 48 8d b8 00 eb b9 92 48 89 f8 48 c1 e8 03 42 80 3c 20 00 74 05 e8 8b 91 8d 00 4d 8b ae 00 0b 00 00 <4d> 8d be 10 0b 00 00 4c 89 f8 48 c1 e8 03 42 80 3c 20 00 74 08 4c RSP: 0018:ffffc90000007bc0 EFLAGS: 00000046 RAX: 1ffff110170e7560 RBX: 0000000000000001 RCX: ffffffff8195111f RDX: 0000000000000000 RSI: 0000000000000008 RDI: ffff8880b873ab00 RBP: ffff88801c2d6548 R08: ffff88801c2d654f R09: 1ffff1100385aca9 R10: dffffc0000000000 R11: ffffed100385acaa R12: dffffc0000000000 R13: ffff88801defbc80 R14: ffff8880b873a000 R15: 0000000000000001 FS: 0000000000000000(0000) GS:ffff888125a9c000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 000000110c456222 CR3: 000000004aca0000 CR4: 00000000003526f0 Call Trace: select_idle_smt kernel/sched/fair.c:7653 [inline] select_idle_sibling kernel/sched/fair.c:7926 [inline] select_task_rq_fair+0x20d2/0x3570 kernel/sched/fair.c:8631 select_task_rq kernel/sched/core.c:3501 [inline] try_to_wake_up+0x4d8/0x12b0 kernel/sched/core.c:4210 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 42 f7 1f 00 fb eb 44 e8 3a f7 1f 00 e8 85 23 bd 09 4d 85 f6 74 94 e8 2b f7 1f 00 fb 48 c7 c7 80 1a 33 8e <31> f6 ba 01 00 00 00 31 c9 41 b8 01 00 00 00 45 31 c9 53 e8 4b 2b RSP: 0018:ffffc9000cb3ece0 EFLAGS: 00000287 RAX: ffffffff81a0de95 RBX: ffffffff81a0dcee RCX: 0000000000100000 RDX: ffffc90015398000 RSI: 00000000000ec28a RDI: ffffffff8e331a80 RBP: ffffc9000cb3edf0 R08: ffffffff8fbf0777 R09: 1ffffffff1f7e0ee R10: dffffc0000000000 R11: fffffbfff1f7e0ef R12: 0000000000000000 R13: 000000000000002c R14: 0000000000000200 R15: 1ffff92001967da0 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_get_langid drivers/usb/core/message.c:936 [inline] usb_string+0x474/0x7e0 drivers/usb/core/message.c:984 usb_cache_string+0x80/0x140 drivers/usb/core/message.c:1030 usb_set_configuration+0x1934/0x2110 drivers/usb/core/message.c:2182 usb_generic_driver_probe+0x8d/0x150 drivers/usb/core/generic.c:250 usb_probe_device+0x1c4/0x3c0 drivers/usb/core/driver.c:291 call_driver_probe drivers/base/dd.c:-1 [inline] really_probe+0x26d/0xad0 drivers/base/dd.c:659 __driver_probe_device+0x18c/0x320 drivers/base/dd.c:801 driver_probe_device+0x4f/0x240 drivers/base/dd.c:831 __device_attach_driver+0x279/0x430 drivers/base/dd.c:959 bus_for_each_drv+0x251/0x2e0 drivers/base/bus.c:462 __device_attach+0x2b8/0x430 drivers/base/dd.c:1031 bus_probe_device+0x185/0x260 drivers/base/bus.c:537 device_add+0x7b6/0xb80 drivers/base/core.c:3689 usb_new_device+0xa39/0x1720 drivers/usb/core/hub.c:2695 hub_port_connect drivers/usb/core/hub.c:5567 [inline] hub_port_connect_change drivers/usb/core/hub.c:5707 [inline] port_event drivers/usb/core/hub.c:5871 [inline] hub_event+0x29b1/0x4ef0 drivers/usb/core/hub.c:5953 process_one_work+0x94a/0x15d0 kernel/workqueue.c:3267 process_scheduled_works kernel/workqueue.c:3350 [inline] worker_thread+0x9b0/0xee0 kernel/workqueue.c:3431 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