INFO: task syz.0.1864:12138 blocked for more than 143 seconds.
Not tainted syzkaller #0
"echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message.
task:syz.0.1864 state:D stack:28744 pid:12138 tgid:12137 ppid:5820 task_flags:0x400140 flags:0x00080002
Call Trace:
context_switch kernel/sched/core.c:5264 [inline]
__schedule+0x1848/0x4ec0 kernel/sched/core.c:6872
__schedule_loop kernel/sched/core.c:6954 [inline]
schedule+0x165/0x360 kernel/sched/core.c:6969
schedule_preempt_disabled+0x13/0x30 kernel/sched/core.c:7026
__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: 0033:0x7fcc3e18f6c9
RSP: 002b:00007fcc3ef6d038 EFLAGS: 00000246 ORIG_RAX: 00000000000000a5
RAX: ffffffffffffffda RBX: 00007fcc3e3e5fa0 RCX: 00007fcc3e18f6c9
RDX: 0000200000000000 RSI: 0000200000000100 RDI: 0000200000000040
RBP: 00007fcc3e211f91 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000001000080 R11: 0000000000000246 R12: 0000000000000000
R13: 00007fcc3e3e6038 R14: 00007fcc3e3e5fa0 R15: 00007ffd9517bb68
Showing all locks held in the system:
1 lock held by rcu_exp_gp_kthr/18:
#0: ffff8880b873a3d8 (&rq->__lock){-.-.}-{2:2}, at: raw_spin_rq_lock_nested+0x2a/0x140 kernel/sched/core.c:638
2 locks held by kworker/1:0/24:
#0: ffff88813fe55948 ((wq_completion)events){+.+.}-{0:0}, at: process_one_work+0x841/0x15d0 kernel/workqueue.c:3242
#1: ffffc900001e7b80 ((work_completion)(&fw_work->work)){+.+.}-{0:0}, at: process_one_work+0x868/0x15d0 kernel/workqueue.c:3243
1 lock held by khungtaskd/31:
#0: ffffffff8e33b720 (rcu_read_lock){....}-{1:3}, at: rcu_lock_acquire include/linux/rcupdate.h:331 [inline]
#0: ffffffff8e33b720 (rcu_read_lock){....}-{1:3}, at: rcu_read_lock include/linux/rcupdate.h:867 [inline]
#0: ffffffff8e33b720 (rcu_read_lock){....}-{1:3}, at: debug_show_all_locks+0x2e/0x180 kernel/locking/lockdep.c:6775
3 locks held by acpid/5178:
#0: ffff888034396118 (&evdev->mutex){+.+.}-{4:4}, at: evdev_close_device drivers/input/evdev.c:402 [inline]
#0: ffff888034396118 (&evdev->mutex){+.+.}-{4:4}, at: evdev_release+0x706/0x800 drivers/input/evdev.c:447
#1: ffff88807a5402c0 (&dev->mutex#2){+.+.}-{4:4}, at: class_mutex_constructor include/linux/mutex.h:228 [inline]
#1: ffff88807a5402c0 (&dev->mutex#2){+.+.}-{4:4}, at: input_close_device+0x4c/0x280 drivers/input/input.c:646
#2: ffffffff8e3411f8 (rcu_state.exp_mutex){+.+.}-{4:4}, at: exp_funnel_lock kernel/rcu/tree_exp.h:343 [inline]
#2: ffffffff8e3411f8 (rcu_state.exp_mutex){+.+.}-{4:4}, at: synchronize_rcu_expedited+0x3b9/0x730 kernel/rcu/tree_exp.h:957
2 locks held by getty/5585:
#0: ffff88814df3d0a0 (&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/5829:
#0: ffff8880256ae358 (&disk->open_mutex){+.+.}-{4:4}, at: bdev_open+0xe0/0xd30 block/bdev.c:945
5 locks held by kworker/1:4/5914:
#0: ffff88801fea6948 ((wq_completion)usb_hub_wq){+.+.}-{0:0}, at: process_one_work+0x841/0x15d0 kernel/workqueue.c:3242
#1: ffffc90004d5fb80 ((work_completion)(&hub->events)){+.+.}-{0:0}, at: process_one_work+0x868/0x15d0 kernel/workqueue.c:3243
#2: ffff888142f3d198 (&dev->mutex){....}-{4:4}, at: device_lock include/linux/device.h:914 [inline]
#2: ffff888142f3d198 (&dev->mutex){....}-{4:4}, at: hub_event+0x187/0x4ef0 drivers/usb/core/hub.c:5899
#3: ffff8880b873a3d8 (&rq->__lock){-.-.}-{2:2}, at: raw_spin_rq_lock_nested+0x2a/0x140 kernel/sched/core.c:638
#4: ffff8880b8724048 (psi_seq){-.-.}-{0:0}, at: psi_task_switch+0x53/0x880 kernel/sched/psi.c:933
7 locks held by kworker/u8:7/5928:
1 lock held by syz-executor/10886:
#0: ffffffff8e3411f8 (rcu_state.exp_mutex){+.+.}-{4:4}, at: exp_funnel_lock kernel/rcu/tree_exp.h:311 [inline]
#0: ffffffff8e3411f8 (rcu_state.exp_mutex){+.+.}-{4:4}, at: synchronize_rcu_expedited+0x2f6/0x730 kernel/rcu/tree_exp.h:957
2 locks held by syz.0.1864/12138:
#0: ffff88807ce540e0 (&type->s_umount_key#92/1){+.+.}-{4:4}, at: alloc_super+0x1bb/0x960 fs/super.c:344
#1: ffff8880256ae358 (&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 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:336 [inline]
watchdog+0xfa9/0xff0 kernel/hung_task.c:499
kthread+0x711/0x8a0 kernel/kthread.c:463
ret_from_fork+0x599/0xb30 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: 5914 Comm: kworker/1:4 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:io_serial_out+0x7c/0xc0 drivers/tty/serial/8250/8250_port.c:407
Code: ce 9b fc 44 89 f9 d3 e5 49 83 c6 40 4c 89 f0 48 c1 e8 03 42 80 3c 20 00 74 08 4c 89 f7 e8 8c 39 02 fd 41 03 2e 89 d8 89 ea ee <5b> 41 5c 41 5e 41 5f 5d e9 87 9c 42 06 cc 44 89 f9 80 e1 07 38 c1
RSP: 0018:ffffc90004d5ee50 EFLAGS: 00000002
RAX: 0000000000000033 RBX: 0000000000000033 RCX: 0000000000000000
RDX: 00000000000003f8 RSI: 0000000000064d36 RDI: 0000000000064d37
RBP: 00000000000003f8 R08: ffff8881413e0237 R09: 1ffff1102827c046
R10: dffffc0000000000 R11: ffffffff85260110 R12: dffffc0000000000
R13: ffffffff99c9b98b R14: ffffffff99faf4c0 R15: 0000000000000000
FS: 0000000000000000(0000) GS:ffff888125b79000(0000) knlGS:0000000000000000
CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 00007fb344fb12f8 CR3: 0000000078d6c000 CR4: 00000000003526f0
DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000400
DR3: 0000000000000000 DR6: 00000000ffff4ff0 DR7: 0000000000000400
Call Trace:
serial_port_out include/linux/serial_core.h:811 [inline]
serial8250_console_putchar drivers/tty/serial/8250/8250_port.c:3192 [inline]
serial8250_console_fifo_write drivers/tty/serial/8250/8250_port.c:-1 [inline]
serial8250_console_write+0x1410/0x1ba0 drivers/tty/serial/8250/8250_port.c:3342
console_emit_next_record kernel/printk/printk.c:3108 [inline]
console_flush_one_record kernel/printk/printk.c:3194 [inline]
console_flush_all+0x6f6/0xb10 kernel/printk/printk.c:3268
__console_flush_and_unlock kernel/printk/printk.c:3298 [inline]
console_unlock+0xbb/0x190 kernel/printk/printk.c:3338
vprintk_emit+0x4c5/0x590 kernel/printk/printk.c:2423
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
hub_port_init+0x5e6/0x28e0 drivers/usb/core/hub.c:4996
hub_port_connect drivers/usb/core/hub.c:5496 [inline]
hub_port_connect_change drivers/usb/core/hub.c:5707 [inline]
port_event drivers/usb/core/hub.c:5871 [inline]
hub_event+0x2573/0x4ef0 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+0x599/0xb30 arch/x86/kernel/process.c:158
ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:245