INFO: task kworker/1:2:19795 blocked for more than 143 seconds.
Not tainted syzkaller #0
"echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message.
task:kworker/1:2 state:D stack:21048 pid:19795 tgid:19795 ppid:2 task_flags:0x4288060 flags:0x00080000
Workqueue: usb_hub_wq hub_event
Call Trace:
context_switch kernel/sched/core.c:5583 [inline]
__schedule+0x1325/0x4900 kernel/sched/core.c:7382
__schedule_loop kernel/sched/core.c:7459 [inline]
schedule+0xdd/0x2c0 kernel/sched/core.c:7474
schedule_preempt_disabled+0x13/0x30 kernel/sched/core.c:7531
rwsem_down_write_slowpath+0x4c6/0x12f0 kernel/locking/rwsem.c:1215
__down_write_common kernel/locking/rwsem.c:1347 [inline]
__down_write kernel/locking/rwsem.c:1356 [inline]
down_write+0x1bb/0x1f0 kernel/locking/rwsem.c:1632
usb_deregister_dev+0x7c/0x210 drivers/usb/core/file.c:186
sisusb_disconnect+0x5e/0x200 drivers/usb/misc/sisusbvga/sisusbvga.c:2921
usb_unbind_interface+0x1dd/0x9b0 drivers/usb/core/driver.c:460
device_remove drivers/base/dd.c:619 [inline]
device_remove+0x12a/0x180 drivers/base/dd.c:611
__device_release_driver drivers/base/dd.c:1357 [inline]
device_release_driver_internal+0x441/0x610 drivers/base/dd.c:1380
bus_remove_device+0x2bc/0x560 drivers/base/bus.c:678
device_del+0x376/0x9b0 drivers/base/core.c:3967
usb_disable_device+0x367/0x810 drivers/usb/core/message.c:1484
usb_disconnect+0x2e2/0x9a0 drivers/usb/core/hub.c:2355
hub_port_connect drivers/usb/core/hub.c:5425 [inline]
hub_port_connect_change drivers/usb/core/hub.c:5725 [inline]
port_event drivers/usb/core/hub.c:5889 [inline]
hub_event+0x1d46/0x4510 drivers/usb/core/hub.c:5971
process_one_work+0xac7/0x1b10 kernel/workqueue.c:3495
process_scheduled_works kernel/workqueue.c:3578 [inline]
worker_thread+0x5ef/0xe50 kernel/workqueue.c:3659
kthread+0x373/0x450 kernel/kthread.c:436
ret_from_fork+0x69f/0xc90 arch/x86/kernel/process.c:158
ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:245
INFO: task syz.2.3834:22604 blocked for more than 143 seconds.
Not tainted syzkaller #0
"echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message.
task:syz.2.3834 state:D stack:29048 pid:22604 tgid:22579 ppid:18904 task_flags:0x400040 flags:0x00080002
Call Trace:
context_switch kernel/sched/core.c:5583 [inline]
__schedule+0x1325/0x4900 kernel/sched/core.c:7382
__schedule_loop kernel/sched/core.c:7459 [inline]
schedule+0xdd/0x2c0 kernel/sched/core.c:7474
schedule_preempt_disabled+0x13/0x30 kernel/sched/core.c:7531
__mutex_lock_common kernel/locking/mutex.c:726 [inline]
__mutex_lock+0xcca/0x1c10 kernel/locking/mutex.c:821
sisusb_open+0xb6/0x4b0 drivers/usb/misc/sisusbvga/sisusbvga.c:2213
usb_open+0x189/0x220 drivers/usb/core/file.c:47
chrdev_open+0x234/0x6a0 fs/char_dev.c:413
do_dentry_open+0x653/0x1460 fs/open.c:1000
vfs_open_consume+0xcc/0x460 fs/open.c:1131
do_open fs/namei.c:4851 [inline]
path_openat+0x1547/0x23f0 fs/namei.c:5016
do_file_open+0x20e/0x430 fs/namei.c:5045
do_sys_openat2+0x163/0x1d0 fs/open.c:1442
do_sys_open fs/open.c:1448 [inline]
__do_sys_openat fs/open.c:1464 [inline]
__se_sys_openat fs/open.c:1459 [inline]
__x64_sys_openat+0x12d/0x210 fs/open.c:1459
do_syscall_x64 arch/x86/entry/syscall_64.c:61 [inline]
do_syscall_64+0x119/0x710 arch/x86/entry/syscall_64.c:84
entry_SYSCALL_64_after_hwframe+0x77/0x7f
RIP: 0033:0x7f68adc6034e
RSP: 002b:00007f68ac6d5b28 EFLAGS: 00000246 ORIG_RAX: 0000000000000101
RAX: ffffffffffffffda RBX: 00007f68ac6d66c0 RCX: 00007f68adc6034e
RDX: 0000000000000002 RSI: 00007f68ac6d5c00 RDI: ffffffffffffff9c
RBP: 00007f68add37b70 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000
R13: 00007f68adf26128 R14: 00007f68adf26090 R15: 00007ffde330c018
INFO: task syz.2.3834:22618 blocked for more than 143 seconds.
Not tainted syzkaller #0
"echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message.
task:syz.2.3834 state:D stack:29048 pid:22618 tgid:22579 ppid:18904 task_flags:0x400040 flags:0x00080002
Call Trace:
context_switch kernel/sched/core.c:5583 [inline]
__schedule+0x1325/0x4900 kernel/sched/core.c:7382
__schedule_loop kernel/sched/core.c:7459 [inline]
schedule+0xdd/0x2c0 kernel/sched/core.c:7474
schedule_preempt_disabled+0x13/0x30 kernel/sched/core.c:7531
__mutex_lock_common kernel/locking/mutex.c:726 [inline]
__mutex_lock+0xcca/0x1c10 kernel/locking/mutex.c:821
sisusb_open+0xb6/0x4b0 drivers/usb/misc/sisusbvga/sisusbvga.c:2213
usb_open+0x189/0x220 drivers/usb/core/file.c:47
chrdev_open+0x234/0x6a0 fs/char_dev.c:413
do_dentry_open+0x653/0x1460 fs/open.c:1000
vfs_open_consume+0xcc/0x460 fs/open.c:1131
do_open fs/namei.c:4851 [inline]
path_openat+0x1547/0x23f0 fs/namei.c:5016
do_file_open+0x20e/0x430 fs/namei.c:5045
do_sys_openat2+0x163/0x1d0 fs/open.c:1442
do_sys_open fs/open.c:1448 [inline]
__do_sys_openat fs/open.c:1464 [inline]
__se_sys_openat fs/open.c:1459 [inline]
__x64_sys_openat+0x12d/0x210 fs/open.c:1459
do_syscall_x64 arch/x86/entry/syscall_64.c:61 [inline]
do_syscall_64+0x119/0x710 arch/x86/entry/syscall_64.c:84
entry_SYSCALL_64_after_hwframe+0x77/0x7f
RIP: 0033:0x7f68adc6034e
RSP: 002b:00007f68ac6b4b28 EFLAGS: 00000246 ORIG_RAX: 0000000000000101
RAX: ffffffffffffffda RBX: 00007f68ac6b56c0 RCX: 00007f68adc6034e
RDX: 0000000000000002 RSI: 00007f68ac6b4c00 RDI: ffffffffffffff9c
RBP: 00007f68add37b70 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000
R13: 00007f68adf26218 R14: 00007f68adf26180 R15: 00007ffde330c018
Showing all locks held in the system:
locks held by pr/ttyS0/30: 2, last CPU#0:
#0: ffffffff898d3958 (console_srcu){....}-{0:0}, at: rcu_try_lock_acquire include/linux/rcupdate.h:314 [inline]
#0: ffffffff898d3958 (console_srcu){....}-{0:0}, at: srcu_read_lock_nmisafe include/linux/srcu.h:493 [inline]
#0: ffffffff898d3958 (console_srcu){....}-{0:0}, at: console_srcu_read_lock+0x49/0x60 kernel/printk/printk.c:291
#1: ffffffff94511cb8 (&port_lock_key){-.-.}-{3:3}, at: __uart_port_lock_irqsave include/linux/serial_core.h:613 [inline]
#1: ffffffff94511cb8 (&port_lock_key){-.-.}-{3:3}, at: univ8250_console_device_lock+0x64/0xc0 drivers/tty/serial/8250/8250_core.c:413
locks held by khungtaskd/31: 1, last CPU#1:
#0: ffffffff898e7720 (rcu_read_lock){....}-{1:3}, at: rcu_lock_acquire include/linux/rcupdate.h:309 [inline]
#0: ffffffff898e7720 (rcu_read_lock){....}-{1:3}, at: rcu_read_lock include/linux/rcupdate.h:849 [inline]
#0: ffffffff898e7720 (rcu_read_lock){....}-{1:3}, at: debug_show_all_locks+0x3d/0x184 kernel/locking/lockdep.c:6871
locks held by getty/2924: 2, on CPU#1:
#0: ffff8881124540a0 (&tty->ldisc_sem){++++}-{0:0}, at: tty_ldisc_ref_wait+0x24/0x80 drivers/tty/tty_ldisc.c:243
#1: ffffc900000452e8 (&ldata->atomic_read_lock){+.+.}-{4:4}, at: n_tty_read+0x419/0x1540 drivers/tty/n_tty.c:2211
locks held by udevd/5222: 4, on CPU#1:
#0: ffff88812faf7518 (&p->lock){+.+.}-{4:4}, at: seq_read_iter+0xe1/0x1270 fs/seq_file.c:183
#1: ffff88811fc92880 (&of->mutex#2){+.+.}-{4:4}, at: kernfs_seq_start+0x4f/0x2a0 fs/kernfs/file.c:165
#2: ffff88811ae11878 (kn->active#26){++++}-{0:0}, at: kernfs_get_active_of fs/kernfs/file.c:73 [inline]
#2: ffff88811ae11878 (kn->active#26){++++}-{0:0}, at: kernfs_seq_start+0xbc/0x2a0 fs/kernfs/file.c:166
#3: ffff88811e2781d8 (&dev->mutex){....}-{4:4}, at: device_lock_interruptible include/linux/device.h:1114 [inline]
#3: ffff88811e2781d8 (&dev->mutex){....}-{4:4}, at: manufacturer_show+0x26/0xa0 drivers/usb/core/sysfs.c:142
locks held by udevd/5224: 4, on CPU#1:
#0: ffff88811c338f38 (&p->lock){+.+.}-{4:4}, at: seq_read_iter+0xe1/0x1270 fs/seq_file.c:183
#1: ffff888133fbb480 (&of->mutex#2){+.+.}-{4:4}, at: kernfs_seq_start+0x4f/0x2a0 fs/kernfs/file.c:165
#2: ffff88811462bb48 (kn->active#26){++++}-{0:0}, at: kernfs_get_active_of fs/kernfs/file.c:73 [inline]
#2: ffff88811462bb48 (kn->active#26){++++}-{0:0}, at: kernfs_seq_start+0xbc/0x2a0 fs/kernfs/file.c:166
#3: ffff8881063961d8 (&dev->mutex){....}-{4:4}, at: device_lock_interruptible include/linux/device.h:1114 [inline]
#3: ffff8881063961d8 (&dev->mutex){....}-{4:4}, at: manufacturer_show+0x26/0xa0 drivers/usb/core/sysfs.c:142
locks held by kworker/0:3/5235: 6, on CPU#0:
#0: ffff888105ea3d48 ((wq_completion)usb_hub_wq){+.+.}-{0:0}, at: process_one_work+0x1461/0x1b10 kernel/workqueue.c:3470
#1: ffffc9000201fd18 ((work_completion)(&hub->events)){+.+.}-{0:0}, at: process_one_work+0xa2c/0x1b10 kernel/workqueue.c:3471
#2: ffff888109f211d8 (&dev->mutex){....}-{4:4}, at: device_lock include/linux/device.h:1109 [inline]
#2: ffff888109f211d8 (&dev->mutex){....}-{4:4}, at: hub_event+0x1bb/0x4510 drivers/usb/core/hub.c:5917
#3: ffff8881215d21d8 (&dev->mutex){....}-{4:4}, at: device_lock include/linux/device.h:1109 [inline]
#3: ffff8881215d21d8 (&dev->mutex){....}-{4:4}, at: __device_attach+0x7e/0x4c0 drivers/base/dd.c:1106
#4: ffff8881143011a0 (&dev->mutex){....}-{4:4}, at: device_lock include/linux/device.h:1109 [inline]
#4: ffff8881143011a0 (&dev->mutex){....}-{4:4}, at: __device_attach+0x7e/0x4c0 drivers/base/dd.c:1106
#5: ffffffff8a576fe8 (minor_rwsem#2){++++}-{4:4}, at: usb_register_dev+0x11d/0x570 drivers/usb/core/file.c:134
locks held by kworker/1:4/5243: 6, on CPU#1:
#0: ffff888105ea3d48 ((wq_completion)usb_hub_wq){+.+.}-{0:0}, at: process_one_work+0x1461/0x1b10 kernel/workqueue.c:3470
#1: ffffc9000203fd18 ((work_completion)(&hub->events)){+.+.}-{0:0}, at: process_one_work+0xa2c/0x1b10 kernel/workqueue.c:3471
#2: ffff88810af091d8 (&dev->mutex){....}-{4:4}, at: device_lock include/linux/device.h:1109 [inline]
#2: ffff88810af091d8 (&dev->mutex){....}-{4:4}, at: hub_event+0x1bb/0x4510 drivers/usb/core/hub.c:5917
#3: ffff8881063961d8 (&dev->mutex){....}-{4:4}, at: device_lock include/linux/device.h:1109 [inline]
#3: ffff8881063961d8 (&dev->mutex){....}-{4:4}, at: __device_attach+0x7e/0x4c0 drivers/base/dd.c:1106
#4: ffff88811f6b21a0 (&dev->mutex){....}-{4:4}, at: device_lock include/linux/device.h:1109 [inline]
#4: ffff88811f6b21a0 (&dev->mutex){....}-{4:4}, at: __device_attach+0x7e/0x4c0 drivers/base/dd.c:1106
#5: ffffffff8a576fe8 (minor_rwsem#2){++++}-{4:4}, at: usb_register_dev+0x11d/0x570 drivers/usb/core/file.c:134
locks held by kworker/1:5/5246: 6, on CPU#1:
#0: ffff888105ea3d48 ((wq_completion)usb_hub_wq){+.+.}-{0:0}, at: process_one_work+0x1461/0x1b10 kernel/workqueue.c:3470
#1: ffffc9000205fd18 ((work_completion)(&hub->events)){+.+.}-{0:0}, at: process_one_work+0xa2c/0x1b10 kernel/workqueue.c:3471
#2: ffff8881097c91d8 (&dev->mutex){....}-{4:4}, at: device_lock include/linux/device.h:1109 [inline]
#2: ffff8881097c91d8 (&dev->mutex){....}-{4:4}, at: hub_event+0x1bb/0x4510 drivers/usb/core/hub.c:5917
#3: ffff88811e2781d8 (&dev->mutex){....}-{4:4}, at: device_lock include/linux/device.h:1109 [inline]
#3: ffff88811e2781d8 (&dev->mutex){....}-{4:4}, at: __device_attach+0x7e/0x4c0 drivers/base/dd.c:1106
#4: ffff88811cf3b1a0 (&dev->mutex){....}-{4:4}, at: device_lock include/linux/device.h:1109 [inline]
#4: ffff88811cf3b1a0 (&dev->mutex){....}-{4:4}, at: __device_attach+0x7e/0x4c0 drivers/base/dd.c:1106
#5: ffffffff8a576fe8 (minor_rwsem#2){++++}-{4:4}, at: usb_register_dev+0x11d/0x570 drivers/usb/core/file.c:134
locks held by kworker/0:4/5269: 6, on CPU#0:
#0: ffff888105ea3d48 ((wq_completion)usb_hub_wq){+.+.}-{0:0}, at: process_one_work+0x1461/0x1b10 kernel/workqueue.c:3470
#1: ffffc90001de7d18 ((work_completion)(&hub->events)){+.+.}-{0:0}, at: process_one_work+0xa2c/0x1b10 kernel/workqueue.c:3471
#2: ffff888109ff11d8 (&dev->mutex){....}-{4:4}, at: device_lock include/linux/device.h:1109 [inline]
#2: ffff888109ff11d8 (&dev->mutex){....}-{4:4}, at: hub_event+0x1bb/0x4510 drivers/usb/core/hub.c:5917
#3: ffff88810fb731d8 (&dev->mutex){....}-{4:4}, at: device_lock include/linux/device.h:1109 [inline]
#3: ffff88810fb731d8 (&dev->mutex){....}-{4:4}, at: __device_attach+0x7e/0x4c0 drivers/base/dd.c:1106
#4: ffff88813af041a0 (&dev->mutex){....}-{4:4}, at: device_lock include/linux/device.h:1109 [inline]
#4: ffff88813af041a0 (&dev->mutex){....}-{4:4}, at: __device_attach+0x7e/0x4c0 drivers/base/dd.c:1106
#5: ffffffff8a576fe8 (minor_rwsem#2){++++}-{4:4}, at: usb_register_dev+0x11d/0x570 drivers/usb/core/file.c:134
locks held by udevd/5490: 4, on CPU#0:
#0: ffff8881357371b8 (&p->lock){+.+.}-{4:4}, at: seq_read_iter+0xe1/0x1270 fs/seq_file.c:183
#1: ffff888113a2f480 (&of->mutex#2){+.+.}-{4:4}, at: kernfs_seq_start+0x4f/0x2a0 fs/kernfs/file.c:165
#2: ffff888119489698 (kn->active#26){++++}-{0:0}, at: kernfs_get_active_of fs/kernfs/file.c:73 [inline]
#2: ffff888119489698 (kn->active#26){++++}-{0:0}, at: kernfs_seq_start+0xbc/0x2a0 fs/kernfs/file.c:166
#3: ffff88810fb731d8 (&dev->mutex){....}-{4:4}, at: device_lock_interruptible include/linux/device.h:1114 [inline]
#3: ffff88810fb731d8 (&dev->mutex){....}-{4:4}, at: manufacturer_show+0x26/0xa0 drivers/usb/core/sysfs.c:142
locks held by kworker/1:2/19795: 6, on CPU#1:
#0: ffff888105ea3d48 ((wq_completion)usb_hub_wq){+.+.}-{0:0}, at: process_one_work+0x1461/0x1b10 kernel/workqueue.c:3470
#1: ffffc900016d7d18 ((work_completion)(&hub->events)){+.+.}-{0:0}, at: process_one_work+0xa2c/0x1b10 kernel/workqueue.c:3471
#2: ffff888108f911d8 (&dev->mutex){....}-{4:4}, at: device_lock include/linux/device.h:1109 [inline]
#2: ffff888108f911d8 (&dev->mutex){....}-{4:4}, at: hub_event+0x1bb/0x4510 drivers/usb/core/hub.c:5917
#3: ffff88811cf271d8 (&dev->mutex){....}-{4:4}, at: device_lock include/linux/device.h:1109 [inline]
#3: ffff88811cf271d8 (&dev->mutex){....}-{4:4}, at: usb_disconnect+0x10a/0x9a0 drivers/usb/core/hub.c:2346
#4: ffff88813baa01a0 (&dev->mutex){....}-{4:4}, at: device_lock include/linux/device.h:1109 [inline]
#4: ffff88813baa01a0 (&dev->mutex){....}-{4:4}, at: __device_driver_lock drivers/base/dd.c:1046 [inline]
#4: ffff88813baa01a0 (&dev->mutex){....}-{4:4}, at: device_release_driver_internal+0xa7/0x610 drivers/base/dd.c:1377
#5: ffffffff8a576fe8 (minor_rwsem#2){++++}-{4:4}, at: usb_deregister_dev+0x7c/0x210 drivers/usb/core/file.c:186
locks held by kworker/0:6/20770: 3, on CPU#0:
#0: ffff88810006a948 ((wq_completion)events){+.+.}-{0:0}, at: process_one_work+0x1461/0x1b10 kernel/workqueue.c:3470
#1: ffffc90002167d18 ((work_completion)(&(&d->rc_query_work)->work)){+.+.}-{0:0}, at: process_one_work+0xa2c/0x1b10 kernel/workqueue.c:3471
#2: ffff88812fbfd010 (&d->i2c_mutex){+.+.}-{4:4}, at: technisat_usb2_get_ir drivers/media/usb/dvb-usb/technisat-usb2.c:621 [inline]
#2: ffff88812fbfd010 (&d->i2c_mutex){+.+.}-{4:4}, at: technisat_usb2_rc_query+0x1ba/0x630 drivers/media/usb/dvb-usb/technisat-usb2.c:677
locks held by syz.2.3834/22581: 2, on CPU#1:
#0: ffffffff8a576fe8 (minor_rwsem#2){++++}-{4:4}, at: usb_open+0x23/0x220 drivers/usb/core/file.c:38
#1: ffff88810eb420c8 (&(sisusb->lock)){+.+.}-{4:4}, at: sisusb_open+0xb6/0x4b0 drivers/usb/misc/sisusbvga/sisusbvga.c:2213
locks held by syz.2.3834/22604: 2, on CPU#0:
#0: ffffffff8a576fe8 (minor_rwsem#2){++++}-{4:4}, at: usb_open+0x23/0x220 drivers/usb/core/file.c:38
#1: ffff88810eb420c8 (&(sisusb->lock)){+.+.}-{4:4}, at: sisusb_open+0xb6/0x4b0 drivers/usb/misc/sisusbvga/sisusbvga.c:2213
locks held by syz.2.3834/22618: 2, on CPU#0:
#0: ffffffff8a576fe8 (minor_rwsem#2){++++}-{4:4}, at: usb_open+0x23/0x220 drivers/usb/core/file.c:38
#1: ffff88810eb420c8 (&(sisusb->lock)){+.+.}-{4:4}, at: sisusb_open+0xb6/0x4b0 drivers/usb/misc/sisusbvga/sisusbvga.c:2213
=============================================
NMI backtrace for cpu 1
CPU: 1 UID: 0 PID: 31 Comm: khungtaskd Not tainted syzkaller #0 PREEMPT(lazy)
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 10/15/2026
Call Trace:
__dump_stack lib/dump_stack.c:94 [inline]
dump_stack_lvl+0x100/0x190 lib/dump_stack.c:120
nmi_cpu_backtrace.cold+0x12d/0x151 lib/nmi_backtrace.c:123
nmi_trigger_cpumask_backtrace+0x21f/0x2a0 lib/nmi_backtrace.c:66
trigger_all_cpu_backtrace include/linux/nmi.h:164 [inline]
__sys_info lib/sys_info.c:157 [inline]
sys_info+0x141/0x190 lib/sys_info.c:165
check_hung_uninterruptible_tasks kernel/hung_task.c:377 [inline]
watchdog+0xd0f/0x10c0 kernel/hung_task.c:598
kthread+0x373/0x450 kernel/kthread.c:436
ret_from_fork+0x69f/0xc90 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: 30 Comm: pr/ttyS0 Not tainted syzkaller #0 PREEMPT(lazy)
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 10/15/2026
RIP: 0010:io_serial_in+0x87/0xb0 drivers/tty/serial/8250/8250_port.c:426
Code: 44 79 fe 48 8d 7d 40 44 89 e1 48 b8 00 00 00 00 00 fc ff df 48 89 fa d3 e3 48 c1 ea 03 80 3c 02 00 75 1a 66 03 5d 40 89 da ec <5b> 0f b6 c0 5d 41 5c c3 cc cc cc cc e8 58 d0 e9 fe eb a2 e8 e1 d0
RSP: 0018:ffffc90000207960 EFLAGS: 00000002
RAX: dffffc0000000000 RBX: 00000000000003fd RCX: 0000000000000000
RDX: 00000000000003fd RSI: ffffffff833db240 RDI: ffffffff94511ce0
RBP: ffffffff94511ca0 R08: 000000000000001f R09: 0000000000000000
R10: 0000000000000003 R11: 205d395420202020 R12: 0000000000000000
R13: 0000000000000020 R14: fffffbfff28a23f1 R15: dffffc0000000000
FS: 0000000000000000(0000) GS:ffff888268360000(0000) knlGS:0000000000000000
CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 00007fa61a818c80 CR3: 0000000133f34000 CR4: 00000000003506f0
Call Trace:
serial_in drivers/tty/serial/8250/8250.h:134 [inline]
serial_lsr_in drivers/tty/serial/8250/8250.h:156 [inline]
wait_for_lsr+0x13a/0x210 drivers/tty/serial/8250/8250_port.c:2036
serial8250_fifo_wait_for_lsr_thre+0x5f/0xd0 drivers/tty/serial/8250/8250_port.c:3294
__serial8250_console_fifo_write+0xa5/0x290 drivers/tty/serial/8250/8250_port.c:3369
serial8250_console_fifo_write drivers/tty/serial/8250/8250_port.c:3402 [inline]
__serial8250_console_write drivers/tty/serial/8250/8250_port.c:3456 [inline]
serial8250_console_write+0x1108/0x14f0 drivers/tty/serial/8250/8250_port.c:3520
nbcon_emit_next_record+0x8f7/0xa70 kernel/printk/nbcon.c:1070
nbcon_emit_one+0x1a8/0x2b0 kernel/printk/nbcon.c:1157
nbcon_kthread_func+0x5ef/0x7f0 kernel/printk/nbcon.c:1271
kthread+0x373/0x450 kernel/kthread.c:436
ret_from_fork+0x69f/0xc90 arch/x86/kernel/process.c:158
ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:245