INFO: task syz.5.2499:6943 blocked for more than 123 seconds.
Not tainted syzkaller #0
"echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message.
task:syz.5.2499 state:D stack:0 pid:6943 tgid:6939 ppid:1383 flags:0x00000004
Call Trace:
context_switch kernel/sched/core.c:6016 [inline]
__schedule+0x1399/0x1fa0 kernel/sched/core.c:7870
__schedule_loop kernel/sched/core.c:7951 [inline]
schedule+0xc5/0x240 kernel/sched/core.c:7966
schedule_preempt_disabled+0x14/0x30 kernel/sched/core.c:8023
__mutex_lock_common kernel/locking/mutex.c:707 [inline]
__mutex_lock+0x960/0x1bb0 kernel/locking/mutex.c:803
__mutex_lock_slowpath+0xe/0x20 kernel/locking/mutex.c:1134
mutex_lock+0x113/0x1d0 kernel/locking/mutex.c:285
device_lock include/linux/device.h:911 [inline]
usbdev_open+0x16b/0x800 drivers/usb/core/devio.c:1051
chrdev_open+0x4dc/0x600 fs/char_dev.c:414
do_dentry_open+0x97b/0x1510 fs/open.c:960
vfs_open+0x86/0x240 fs/open.c:1092
do_open fs/namei.c:3782 [inline]
path_openat+0x2bb1/0x34f0 fs/namei.c:3941
do_filp_open+0x1f5/0x440 fs/namei.c:3968
do_sys_openat2+0x134/0x1d0 fs/open.c:1440
do_sys_open fs/open.c:1455 [inline]
__do_sys_openat fs/open.c:1471 [inline]
__se_sys_openat fs/open.c:1466 [inline]
__x64_sys_openat+0x13a/0x170 fs/open.c:1466
x64_sys_call+0xe69/0x2ee0 arch/x86/include/generated/asm/syscalls_64.h:258
do_syscall_x64 arch/x86/entry/common.c:47 [inline]
do_syscall_64+0x57/0xf0 arch/x86/entry/common.c:78
entry_SYSCALL_64_after_hwframe+0x76/0x7e
RIP: 0033:0x7f0cf955d04e
RSP: 002b:00007f0cf7ff6b28 EFLAGS: 00000246 ORIG_RAX: 0000000000000101
RAX: ffffffffffffffda RBX: 00007f0cf7ff76c0 RCX: 00007f0cf955d04e
RDX: 000000000000a401 RSI: 00007f0cf7ff6c00 RDI: ffffffffffffff9c
RBP: 00007f0cf7ff6c00 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: cccccccccccccccd
R13: 00007f0cf9816128 R14: 00007f0cf9816090 R15: 00007ffd3b174ae8
NMI backtrace for cpu 1
CPU: 1 UID: 0 PID: 37 Comm: khungtaskd Not tainted syzkaller #0 43b6d7f3e817ec535415847ac2d00a46ab6e4796
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 02/12/2026
Call Trace:
__dump_stack+0x21/0x30 lib/dump_stack.c:94
dump_stack_lvl+0x140/0x1c0 lib/dump_stack.c:120
dump_stack+0x19/0x20 lib/dump_stack.c:129
nmi_cpu_backtrace+0x2ba/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+0xdad/0xf00 kernel/hung_task.c:423
kthread+0x2c9/0x370 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: 388 Comm: kworker/0:5 Not tainted syzkaller #0 43b6d7f3e817ec535415847ac2d00a46ab6e4796
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 02/12/2026
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 54 f0 bb 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:ffffc9000d2ee388 EFLAGS: 00000006
RAX: 0000000000000000 RBX: 0000000000000000 RCX: 0000000000000000
RDX: 00000000000003f9 RSI: 00000000000fffff RDI: 0000000000100000
RBP: ffffc9000d2ee3b0 R08: 0000000000000003 R09: 0000000000000004
R10: 0000000000000000 R11: ffffffff8323e830 R12: 0000000000000000
R13: dffffc0000000000 R14: 00000000000003f9 R15: ffffffff88c1e4c8
FS: 0000000000000000(0000) GS:ffff8881f6e00000(0000) knlGS:0000000000000000
CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 00007f6f49fe92f8 CR3: 000000011665c000 CR4: 00000000003526b0
Call Trace:
serial_out drivers/tty/serial/8250/8250.h:142 [inline]
serial8250_clear_IER drivers/tty/serial/8250/8250_port.c:-1 [inline]
serial8250_console_write+0x3be/0x21a0 drivers/tty/serial/8250/8250_port.c:3386
univ8250_console_write+0x6f/0xb0 drivers/tty/serial/8250/8250_core.c:396
console_emit_next_record kernel/printk/printk.c:3151 [inline]
console_flush_all+0x5fa/0xac0 kernel/printk/printk.c:3239
__console_flush_and_unlock kernel/printk/printk.c:3298 [inline]
console_unlock+0xf8/0x2c0 kernel/printk/printk.c:3338
vprintk_emit+0x282/0x650 kernel/printk/printk.c:2462
dev_vprintk_emit+0x359/0x420 drivers/base/core.c:4962
dev_printk_emit+0xef/0x150 drivers/base/core.c:4973
__netdev_printk+0x3f2/0x4e0 net/core/dev.c:11918
netdev_err+0x11f/0x190 net/core/dev.c:11970
asix_set_sw_mii drivers/net/usb/asix_common.c:78 [inline]
asix_check_host_enable drivers/net/usb/asix_common.c:98 [inline]
__asix_mdio_read drivers/net/usb/asix_common.c:489 [inline]
asix_mdio_read+0x222/0x4d0 drivers/net/usb/asix_common.c:512
asix_phy_reset+0xcc/0x1d0 drivers/net/usb/asix_devices.c:215
ax88172_bind+0x472/0x5d0 drivers/net/usb/asix_devices.c:277
usbnet_probe+0x9c3/0x2960 drivers/net/usb/usbnet.c:1779
usb_probe_interface+0x6a9/0xc00 drivers/usb/core/driver.c:400
call_driver_probe drivers/base/dd.c:-1 [inline]
really_probe+0x2d8/0x890 drivers/base/dd.c:657
__driver_probe_device+0x198/0x280 drivers/base/dd.c:799
driver_probe_device+0x54/0x3f0 drivers/base/dd.c:829
__device_attach_driver+0x2f1/0x4b0 drivers/base/dd.c:957
bus_for_each_drv+0x267/0x300 drivers/base/bus.c:459
__device_attach+0x2c9/0x3c0 drivers/base/dd.c:1029
device_initial_probe+0x1e/0x30 drivers/base/dd.c:1078
bus_probe_device+0x18b/0x270 drivers/base/bus.c:534
device_add+0x80c/0xbf0 drivers/base/core.c:3692
usb_set_configuration+0x1acf/0x20b0 drivers/usb/core/message.c:2210
usb_generic_driver_probe+0x95/0x160 drivers/usb/core/generic.c:254
usb_probe_device+0x1d1/0x380 drivers/usb/core/driver.c:295
call_driver_probe drivers/base/dd.c:-1 [inline]
really_probe+0x2d8/0x890 drivers/base/dd.c:657
__driver_probe_device+0x198/0x280 drivers/base/dd.c:799
driver_probe_device+0x54/0x3f0 drivers/base/dd.c:829
__device_attach_driver+0x2f1/0x4b0 drivers/base/dd.c:957
bus_for_each_drv+0x267/0x300 drivers/base/bus.c:459
__device_attach+0x2c9/0x3c0 drivers/base/dd.c:1029
device_initial_probe+0x1e/0x30 drivers/base/dd.c:1078
bus_probe_device+0x18b/0x270 drivers/base/bus.c:534
device_add+0x80c/0xbf0 drivers/base/core.c:3692
usb_new_device+0x9f8/0x15b0 drivers/usb/core/hub.c:2703
hub_port_connect drivers/usb/core/hub.c:5574 [inline]
hub_port_connect_change drivers/usb/core/hub.c:5714 [inline]
port_event drivers/usb/core/hub.c:5878 [inline]
hub_event+0x30c6/0x4700 drivers/usb/core/hub.c:5960
process_one_work kernel/workqueue.c:3238 [inline]
process_scheduled_works+0x7d1/0x1020 kernel/workqueue.c:3319
worker_thread+0xc70/0x10b0 kernel/workqueue.c:3400
kthread+0x2c9/0x370 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