INFO: task syz.8.5280:17319 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.8.5280 state:D stack:0 pid:17319 tgid:17318 ppid:17261 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: 0033:0x7f2db2d8d550 RSP: 002b:00007f2db3ba6b70 EFLAGS: 00000293 ORIG_RAX: 0000000000000101 RAX: ffffffffffffffda RBX: 0000000000101301 RCX: 00007f2db2d8d550 RDX: 0000000000101301 RSI: 00007f2db3ba6c10 RDI: 00000000ffffff9c RBP: 00007f2db3ba6c10 R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000293 R12: cccccccccccccccd R13: 00007f2db2fb6038 R14: 00007f2db2fb5fa0 R15: 00007fffa421c5b8 NMI backtrace for cpu 0 CPU: 0 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 0 to CPUs 1: NMI backtrace for cpu 1 CPU: 1 UID: 0 PID: 565 Comm: kworker/1:4 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_in+0x7b/0xc0 drivers/tty/serial/8250/8250_port.c:406 Code: e8 9a aa 6d fe 44 89 f9 d3 e3 49 83 c6 08 4c 89 f0 48 c1 e8 03 42 80 3c 20 00 74 08 4c 89 f7 e8 3b d4 c3 fe 41 03 1e 89 da ec <0f> b6 c0 5b 41 5c 41 5e 41 5f 5d e9 45 1a 71 02 cc 44 89 f9 80 e1 RSP: 0018:ffffc9000c4b63b0 EFLAGS: 00000002 RAX: 1ffffffff113bf60 RBX: 00000000000003fd RCX: 0000000000000000 RDX: 00000000000003fd RSI: 00000000000fffff RDI: 0000000000100000 RBP: ffffc9000c4b63d0 R08: ffff88810628c107 R09: 1ffff11020c51820 R10: 0000000000000000 R11: ffffffff83182090 R12: dffffc0000000000 R13: 0000000000000000 R14: ffffffff889dfde8 R15: 0000000000000000 FS: 0000000000000000(0000) GS:ffff8881f6f00000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 000055557859a4a8 CR3: 000000010b3a6000 CR4: 00000000003526b0 Call Trace: serial_in drivers/tty/serial/8250/8250.h:137 [inline] serial_lsr_in drivers/tty/serial/8250/8250.h:159 [inline] wait_for_lsr drivers/tty/serial/8250/8250_port.c:2069 [inline] fifo_wait_for_lsr drivers/tty/serial/8250/8250_port.c:3315 [inline] serial8250_console_fifo_write drivers/tty/serial/8250/8250_port.c:3337 [inline] serial8250_console_write+0x1395/0x2130 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 __netdev_printk+0x3f2/0x4e0 net/core/dev.c:11899 netdev_err+0x10b/0x170 net/core/dev.c:11951 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:484 [inline] asix_mdio_read+0x20a/0x4b0 drivers/net/usb/asix_common.c:507 asix_phy_reset+0xcc/0x1d0 drivers/net/usb/asix_devices.c:215 ax88172_bind+0x3f1/0x590 drivers/net/usb/asix_devices.c:275 usbnet_probe+0x9a7/0x2850 drivers/net/usb/usbnet.c:1772 usb_probe_interface+0x696/0xc00 drivers/usb/core/driver.c:403 call_driver_probe drivers/base/dd.c:-1 [inline] really_probe+0x2d6/0x890 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+0x260/0x2f0 drivers/base/bus.c:459 __device_attach+0x2bd/0x3a0 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/0xc00 drivers/base/core.c:3692 usb_set_configuration+0x1ad4/0x20b0 drivers/usb/core/message.c:2210 usb_generic_driver_probe+0x95/0x160 drivers/usb/core/generic.c:254 usb_probe_device+0x1d4/0x380 drivers/usb/core/driver.c:298 call_driver_probe drivers/base/dd.c:-1 [inline] really_probe+0x2d6/0x890 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+0x260/0x2f0 drivers/base/bus.c:459 __device_attach+0x2bd/0x3a0 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/0xc00 drivers/base/core.c:3692 usb_new_device+0x9ed/0x1590 drivers/usb/core/hub.c:2662 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