INFO: task syz.5.1117:3878 blocked for more than 122 seconds.
Not tainted 6.12.38-syzkaller-ge5a17398e40d #0
"echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message.
task:syz.5.1117 state:D stack:0 pid:3878 tgid:3876 ppid:3594 flags:0x00000004
Call Trace:
context_switch kernel/sched/core.c:5945 [inline]
__schedule+0x1322/0x1df0 kernel/sched/core.c:7791
__schedule_loop kernel/sched/core.c:7872 [inline]
schedule+0xc6/0x240 kernel/sched/core.c:7887
schedule_preempt_disabled+0x14/0x30 kernel/sched/core.c:7944
__mutex_lock_common kernel/locking/mutex.c:707 [inline]
__mutex_lock+0x81e/0x1b50 kernel/locking/mutex.c:803
__mutex_lock_slowpath+0xe/0x20 kernel/locking/mutex.c:1134
mutex_lock+0x102/0x1c0 kernel/locking/mutex.c:285
device_lock include/linux/device.h:908 [inline]
usbdev_open+0x171/0x840 drivers/usb/core/devio.c:1051
chrdev_open+0x4db/0x5f0 fs/char_dev.c:414
do_dentry_open+0x97b/0x1510 fs/open.c:960
vfs_open+0x86/0x230 fs/open.c:1090
do_open fs/namei.c:3774 [inline]
path_openat+0x2b6c/0x34b0 fs/namei.c:3933
do_filp_open+0x1c6/0x3e0 fs/namei.c:3960
do_sys_openat2+0x12c/0x1c0 fs/open.c:1438
do_sys_open fs/open.c:1453 [inline]
__do_sys_openat fs/open.c:1469 [inline]
__se_sys_openat fs/open.c:1464 [inline]
__x64_sys_openat+0x13a/0x170 fs/open.c:1464
x64_sys_call+0xe69/0x2ee0 arch/x86/include/generated/asm/syscalls_64.h:258
do_syscall_x64 arch/x86/entry/common.c:52 [inline]
do_syscall_64+0x58/0xf0 arch/x86/entry/common.c:83
entry_SYSCALL_64_after_hwframe+0x76/0x7e
RIP: 0033:0x7fae8d38d550
RSP: 002b:00007fae8bdf6b70 EFLAGS: 00000293 ORIG_RAX: 0000000000000101
RAX: ffffffffffffffda RBX: 0000000000000082 RCX: 00007fae8d38d550
RDX: 0000000000000082 RSI: 00007fae8bdf6c10 RDI: 00000000ffffff9c
RBP: 00007fae8bdf6c10 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000293 R12: cccccccccccccccd
R13: 00007fae8d5b6038 R14: 00007fae8d5b5fa0 R15: 00007fff711c3808
NMI backtrace for cpu 1
CPU: 1 UID: 0 PID: 37 Comm: khungtaskd Not tainted 6.12.38-syzkaller-ge5a17398e40d #0 cff9d6c8e1f79ff946f02ca62e3ab2973be10fb4
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 07/12/2025
Call Trace:
__dump_stack+0x21/0x30 lib/dump_stack.c:94
dump_stack_lvl+0x10c/0x190 lib/dump_stack.c:120
dump_stack+0x19/0x20 lib/dump_stack.c:129
nmi_cpu_backtrace+0x2bf/0x2d0 lib/nmi_backtrace.c:113
nmi_trigger_cpumask_backtrace+0x142/0x2c0 lib/nmi_backtrace.c:62
arch_trigger_cpumask_backtrace+0x14/0x20 arch/x86/kernel/apic/hw_nmi.c:41
trigger_all_cpu_backtrace include/linux/nmi.h:158 [inline]
check_hung_uninterruptible_tasks kernel/hung_task.c:267 [inline]
watchdog+0xd8f/0xed0 kernel/hung_task.c:423
kthread+0x2ca/0x370 kernel/kthread.c:389
ret_from_fork+0x67/0xa0 arch/x86/kernel/process.c:153
ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:244
Sending NMI from CPU 1 to CPUs 0:
NMI backtrace for cpu 0
CPU: 0 UID: 0 PID: 10 Comm: kworker/0:1 Not tainted 6.12.38-syzkaller-ge5a17398e40d #0 cff9d6c8e1f79ff946f02ca62e3ab2973be10fb4
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 07/12/2025
Workqueue: usb_hub_wq hub_event
RIP: 0010:io_serial_out+0x85/0xd0 drivers/tty/serial/8250/8250_port.c:413
Code: fe 44 89 e1 41 d3 e6 49 83 c7 08 4c 89 f8 48 c1 e8 03 42 80 3c 28 00 74 08 4c 89 ff e8 64 d3 c3 fe 45 03 37 89 d8 44 89 f2 ee <5b> 41 5c 41 5d 41 5e 41 5f 5d c3 cc cc cc cc cc 44 89 e1 80 e1 07
RSP: 0018:ffffc900000a6d08 EFLAGS: 00000002
RAX: 000000000000005b RBX: 000000000000005b RCX: 0000000000000000
RDX: 00000000000003f8 RSI: 0000000000057042 RDI: 0000000000057043
RBP: ffffc900000a6d30 R08: ffff888101abc107 R09: 1ffff11020357820
R10: 0000000000000000 R11: ffffffff83182160 R12: 0000000000000000
R13: dffffc0000000000 R14: 00000000000003f8 R15: ffffffff889dfde8
FS: 0000000000000000(0000) GS:ffff8881f6e00000(0000) knlGS:0000000000000000
CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 0000000000000000 CR3: 000000011b400000 CR4: 00000000003526b0
DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
DR3: 0000000000000001 DR6: 00000000ffff0ff0 DR7: 0000000000000400
Call Trace:
serial_out drivers/tty/serial/8250/8250.h:142 [inline]
serial8250_console_fifo_write drivers/tty/serial/8250/8250_port.c:-1 [inline]
serial8250_console_write+0x166d/0x2130 drivers/tty/serial/8250/8250_port.c:3422
univ8250_console_write+0x6f/0xb0 drivers/tty/serial/8250/8250_core.c:396
console_emit_next_record kernel/printk/printk.c:3150 [inline]
console_flush_all+0x5e6/0xaa0 kernel/printk/printk.c:3238
__console_flush_and_unlock kernel/printk/printk.c:3297 [inline]
console_unlock+0xe9/0x270 kernel/printk/printk.c:3337
vprintk_emit+0x27c/0x640 kernel/printk/printk.c:2461
dev_vprintk_emit+0x33b/0x400 drivers/base/core.c:4962
dev_printk_emit+0xe1/0x130 drivers/base/core.c:4973
__dev_printk+0x17f/0x1b0 drivers/base/core.c:4985
_dev_notice+0x10b/0x170 drivers/base/core.c:5030
usb_parse_endpoint drivers/usb/core/config.c:393 [inline]
usb_parse_interface drivers/usb/core/config.c:594 [inline]
usb_parse_configuration drivers/usb/core/config.c:807 [inline]
usb_get_configuration+0x296b/0x5030 drivers/usb/core/config.c:956
usb_enumerate_device drivers/usb/core/hub.c:2494 [inline]
usb_new_device+0x146/0x1590 drivers/usb/core/hub.c:2632
hub_port_connect drivers/usb/core/hub.c:5533 [inline]
hub_port_connect_change drivers/usb/core/hub.c:5673 [inline]
port_event drivers/usb/core/hub.c:5837 [inline]
hub_event+0x2c81/0x4270 drivers/usb/core/hub.c:5919
process_one_work kernel/workqueue.c:3238 [inline]
process_scheduled_works+0x7d2/0x1020 kernel/workqueue.c:3319
worker_thread+0xc58/0x1250 kernel/workqueue.c:3400
kthread+0x2ca/0x370 kernel/kthread.c:389
ret_from_fork+0x67/0xa0 arch/x86/kernel/process.c:153
ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:244