INFO: task kworker/1:1:28 blocked for more than 143 seconds.
Not tainted syzkaller #0
"echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message.
task:kworker/1:1 state:D stack:22088 pid:28 tgid:28 ppid:2 task_flags:0x4208060 flags:0x00080000
Workqueue: usb_hub_wq hub_event
Call Trace:
context_switch kernel/sched/core.c:5298 [inline]
__schedule+0xeb1/0x4220 kernel/sched/core.c:6911
__schedule_loop kernel/sched/core.c:6993 [inline]
schedule+0xdd/0x390 kernel/sched/core.c:7008
schedule_preempt_disabled+0x13/0x30 kernel/sched/core.c:7065
__mutex_lock_common kernel/locking/mutex.c:692 [inline]
__mutex_lock+0xc9a/0x1b90 kernel/locking/mutex.c:776
class_mutex_constructor include/linux/mutex.h:253 [inline]
usb_audio_probe+0x38f/0x3a90 sound/usb/card.c:950
usb_probe_interface+0x303/0x8f0 drivers/usb/core/driver.c:396
call_driver_probe drivers/base/dd.c:643 [inline]
really_probe+0x241/0xa60 drivers/base/dd.c:721
__driver_probe_device+0x1de/0x400 drivers/base/dd.c:863
driver_probe_device+0x4c/0x1b0 drivers/base/dd.c:893
__device_attach_driver+0x1df/0x340 drivers/base/dd.c:1021
bus_for_each_drv+0x159/0x1e0 drivers/base/bus.c:500
__device_attach+0x1e4/0x4d0 drivers/base/dd.c:1093
device_initial_probe+0xaf/0xd0 drivers/base/dd.c:1148
bus_probe_device+0x64/0x160 drivers/base/bus.c:613
device_add+0x11d9/0x1950 drivers/base/core.c:3691
usb_set_configuration+0xd97/0x1c60 drivers/usb/core/message.c:2268
usb_generic_driver_probe+0xa1/0xe0 drivers/usb/core/generic.c:250
usb_probe_device+0xef/0x400 drivers/usb/core/driver.c:291
call_driver_probe drivers/base/dd.c:643 [inline]
really_probe+0x241/0xa60 drivers/base/dd.c:721
__driver_probe_device+0x1de/0x400 drivers/base/dd.c:863
driver_probe_device+0x4c/0x1b0 drivers/base/dd.c:893
__device_attach_driver+0x1df/0x340 drivers/base/dd.c:1021
bus_for_each_drv+0x159/0x1e0 drivers/base/bus.c:500
__device_attach+0x1e4/0x4d0 drivers/base/dd.c:1093
device_initial_probe+0xaf/0xd0 drivers/base/dd.c:1148
bus_probe_device+0x64/0x160 drivers/base/bus.c:613
device_add+0x11d9/0x1950 drivers/base/core.c:3691
usb_new_device.cold+0x685/0x115c drivers/usb/core/hub.c:2695
hub_port_connect drivers/usb/core/hub.c:5567 [inline]
hub_port_connect_change drivers/usb/core/hub.c:5707 [inline]
port_event drivers/usb/core/hub.c:5871 [inline]
hub_event+0x314d/0x4af0 drivers/usb/core/hub.c:5953
process_one_work+0xa23/0x19a0 kernel/workqueue.c:3276
process_scheduled_works kernel/workqueue.c:3359 [inline]
worker_thread+0x5ef/0xe50 kernel/workqueue.c:3440
kthread+0x370/0x450 kernel/kthread.c:436
ret_from_fork+0x6c3/0xcb0 arch/x86/kernel/process.c:158
ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:245
INFO: task kworker/1:2:1121 blocked for more than 144 seconds.
Not tainted syzkaller #0
"echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message.
task:kworker/1:2 state:D stack:20680 pid:1121 tgid:1121 ppid:2 task_flags:0x4208060 flags:0x00080000
Workqueue: usb_hub_wq hub_event
Call Trace:
context_switch kernel/sched/core.c:5298 [inline]
__schedule+0xeb1/0x4220 kernel/sched/core.c:6911
__schedule_loop kernel/sched/core.c:6993 [inline]
schedule+0xdd/0x390 kernel/sched/core.c:7008
schedule_preempt_disabled+0x13/0x30 kernel/sched/core.c:7065
__mutex_lock_common kernel/locking/mutex.c:692 [inline]
__mutex_lock+0xc9a/0x1b90 kernel/locking/mutex.c:776
class_mutex_constructor include/linux/mutex.h:253 [inline]
usb_audio_probe+0x38f/0x3a90 sound/usb/card.c:950
usb_probe_interface+0x303/0x8f0 drivers/usb/core/driver.c:396
call_driver_probe drivers/base/dd.c:643 [inline]
really_probe+0x241/0xa60 drivers/base/dd.c:721
__driver_probe_device+0x1de/0x400 drivers/base/dd.c:863
driver_probe_device+0x4c/0x1b0 drivers/base/dd.c:893
__device_attach_driver+0x1df/0x340 drivers/base/dd.c:1021
bus_for_each_drv+0x159/0x1e0 drivers/base/bus.c:500
__device_attach+0x1e4/0x4d0 drivers/base/dd.c:1093
device_initial_probe+0xaf/0xd0 drivers/base/dd.c:1148
bus_probe_device+0x64/0x160 drivers/base/bus.c:613
device_add+0x11d9/0x1950 drivers/base/core.c:3691
usb_set_configuration+0xd97/0x1c60 drivers/usb/core/message.c:2268
usb_generic_driver_probe+0xa1/0xe0 drivers/usb/core/generic.c:250
usb_probe_device+0xef/0x400 drivers/usb/core/driver.c:291
call_driver_probe drivers/base/dd.c:643 [inline]
really_probe+0x241/0xa60 drivers/base/dd.c:721
__driver_probe_device+0x1de/0x400 drivers/base/dd.c:863
driver_probe_device+0x4c/0x1b0 drivers/base/dd.c:893
__device_attach_driver+0x1df/0x340 drivers/base/dd.c:1021
bus_for_each_drv+0x159/0x1e0 drivers/base/bus.c:500
__device_attach+0x1e4/0x4d0 drivers/base/dd.c:1093
device_initial_probe+0xaf/0xd0 drivers/base/dd.c:1148
bus_probe_device+0x64/0x160 drivers/base/bus.c:613
device_add+0x11d9/0x1950 drivers/base/core.c:3691
usb_new_device.cold+0x685/0x115c drivers/usb/core/hub.c:2695
hub_port_connect drivers/usb/core/hub.c:5567 [inline]
hub_port_connect_change drivers/usb/core/hub.c:5707 [inline]
port_event drivers/usb/core/hub.c:5871 [inline]
hub_event+0x314d/0x4af0 drivers/usb/core/hub.c:5953
process_one_work+0xa23/0x19a0 kernel/workqueue.c:3276
process_scheduled_works kernel/workqueue.c:3359 [inline]
worker_thread+0x5ef/0xe50 kernel/workqueue.c:3440
kthread+0x370/0x450 kernel/kthread.c:436
ret_from_fork+0x6c3/0xcb0 arch/x86/kernel/process.c:158
ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:245
Showing all locks held in the system:
6 locks held by kworker/0:1/10:
#0: ffff888103afd948 ((wq_completion)usb_hub_wq){+.+.}-{0:0}, at: process_one_work+0x1310/0x19a0 kernel/workqueue.c:3251
#1: ffffc900000afd18 ((work_completion)(&hub->events)){+.+.}-{0:0}, at: process_one_work+0x988/0x19a0 kernel/workqueue.c:3252
#2: ffff88810ab281e0 (&dev->mutex){....}-{4:4}, at: device_lock include/linux/device.h:949 [inline]
#2: ffff88810ab281e0 (&dev->mutex){....}-{4:4}, at: hub_event+0x1bd/0x4af0 drivers/usb/core/hub.c:5899
#3: ffff888104eea1e0 (&dev->mutex){....}-{4:4}, at: device_lock include/linux/device.h:949 [inline]
#3: ffff888104eea1e0 (&dev->mutex){....}-{4:4}, at: __device_attach+0x7e/0x4d0 drivers/base/dd.c:1068
#4:
ffff8881076aa1a8 (&dev->mutex){....}-{4:4}, at: device_lock include/linux/device.h:949 [inline]
ffff8881076aa1a8 (&dev->mutex){....}-{4:4}, at: __device_attach+0x7e/0x4d0 drivers/base/dd.c:1068
#5: ffffffff8aa21188 (register_mutex#3){+.+.}-{4:4}, at: class_mutex_constructor include/linux/mutex.h:253 [inline]
#5: ffffffff8aa21188 (register_mutex#3){+.+.}-{4:4}, at: usb_audio_probe+0x38f/0x3a90 sound/usb/card.c:950
6 locks held by kworker/1:1/28:
#0: ffff888103afd948 ((wq_completion)usb_hub_wq){+.+.}-{0:0}, at: process_one_work+0x1310/0x19a0 kernel/workqueue.c:3251
#1: ffffc900001e7d18 ((work_completion)(&hub->events)){+.+.}-{0:0}, at: process_one_work+0x988/0x19a0 kernel/workqueue.c:3252
#2: ffff88810a7081e0 (&dev->mutex){....}-{4:4}, at: device_lock include/linux/device.h:949 [inline]
#2: ffff88810a7081e0 (&dev->mutex){....}-{4:4}, at: hub_event+0x1bd/0x4af0 drivers/usb/core/hub.c:5899
#3:
ffff88811e7e81e0 (&dev->mutex){....}-{4:4}, at: device_lock include/linux/device.h:949 [inline]
ffff88811e7e81e0 (&dev->mutex){....}-{4:4}, at: __device_attach+0x7e/0x4d0 drivers/base/dd.c:1068
#4: ffff888112dcc1a8 (&dev->mutex){....}-{4:4}, at: device_lock include/linux/device.h:949 [inline]
#4: ffff888112dcc1a8 (&dev->mutex){....}-{4:4}, at: __device_attach+0x7e/0x4d0 drivers/base/dd.c:1068
#5:
ffffffff8aa21188 (register_mutex#3){+.+.}-{4:4}, at: class_mutex_constructor include/linux/mutex.h:253 [inline]
ffffffff8aa21188 (register_mutex#3){+.+.}-{4:4}, at: usb_audio_probe+0x38f/0x3a90 sound/usb/card.c:950
1 lock held by khungtaskd/30:
#0: ffffffff896de760 (rcu_read_lock){....}-{1:3}, at: rcu_lock_acquire include/linux/rcupdate.h:312 [inline]
#0: ffffffff896de760 (rcu_read_lock){....}-{1:3}, at: rcu_read_lock include/linux/rcupdate.h:850 [inline]
#0: ffffffff896de760 (rcu_read_lock){....}-{1:3}, at: debug_show_all_locks+0x3d/0x184 kernel/locking/lockdep.c:6775
6 locks held by kworker/1:2/1121:
#0: ffff888103afd948 ((wq_completion)usb_hub_wq){+.+.}-{0:0}, at: process_one_work+0x1310/0x19a0 kernel/workqueue.c:3251
#1:
ffffc9000328fd18 ((work_completion)(&hub->events)){+.+.}-{0:0}, at: process_one_work+0x988/0x19a0 kernel/workqueue.c:3252
#2: ffff88810ab081e0 (&dev->mutex){....}-{4:4}, at: device_lock include/linux/device.h:949 [inline]
#2: ffff88810ab081e0 (&dev->mutex){....}-{4:4}, at: hub_event+0x1bd/0x4af0 drivers/usb/core/hub.c:5899
#3: ffff888105a891e0 (&dev->mutex){....}-{4:4}, at: device_lock include/linux/device.h:949 [inline]
#3: ffff888105a891e0 (&dev->mutex){....}-{4:4}, at: __device_attach+0x7e/0x4d0 drivers/base/dd.c:1068
#4:
ffff888132f151a8 (&dev->mutex){....}-{4:4}, at: device_lock include/linux/device.h:949 [inline]
ffff888132f151a8 (&dev->mutex){....}-{4:4}, at: __device_attach+0x7e/0x4d0 drivers/base/dd.c:1068
#5: ffffffff8aa21188 (register_mutex#3){+.+.}-{4:4}, at: class_mutex_constructor include/linux/mutex.h:253 [inline]
#5: ffffffff8aa21188 (register_mutex#3){+.+.}-{4:4}, at: usb_audio_probe+0x38f/0x3a90 sound/usb/card.c:950
2 locks held by getty/2919:
#0: ffff8881162810a0 (&tty->ldisc_sem){++++}-{0:0}, at: tty_ldisc_ref_wait+0x24/0x80 drivers/tty/tty_ldisc.c:243
#1: ffffc900000432f0 (&ldata->atomic_read_lock){+.+.}-{4:4}, at: n_tty_read+0x419/0x1500 drivers/tty/n_tty.c:2211
4 locks held by udevd/5210:
#0: ffff888133b462f0 (&p->lock){+.+.}-{4:4}, at: seq_read_iter+0xe1/0x1270 fs/seq_file.c:183
#1: ffff888135b62088 (&of->mutex#2){+.+.}-{4:4}, at: kernfs_seq_start+0x4f/0x2a0 fs/kernfs/file.c:172
#2: ffff8881157bfe18 (kn->active#20){++++}-{0:0}, at: kernfs_get_active_of fs/kernfs/file.c:80 [inline]
#2: ffff8881157bfe18 (kn->active#20){++++}-{0:0}, at: kernfs_seq_start+0xbc/0x2a0 fs/kernfs/file.c:173
#3: ffff888104eea1e0 (&dev->mutex){....}-{4:4}, at: device_lock_interruptible include/linux/device.h:954 [inline]
#3: ffff888104eea1e0 (&dev->mutex){....}-{4:4}, at: manufacturer_show+0x26/0xa0 drivers/usb/core/sysfs.c:142
4 locks held by udevd/5213:
#0: ffff888123bea9e0 (&p->lock){+.+.}-{4:4}, at: seq_read_iter+0xe1/0x1270 fs/seq_file.c:183
#1: ffff888120a6ec88 (&of->mutex#2){+.+.}-{4:4}, at: kernfs_seq_start+0x4f/0x2a0 fs/kernfs/file.c:172
#2: ffff888114f3e968 (kn->active#20){++++}-{0:0}, at: kernfs_get_active_of fs/kernfs/file.c:80 [inline]
#2: ffff888114f3e968 (kn->active#20){++++}-{0:0}, at: kernfs_seq_start+0xbc/0x2a0 fs/kernfs/file.c:173
#3:
ffff88811e7e81e0 (&dev->mutex){....}-{4:4}, at: device_lock_interruptible include/linux/device.h:954 [inline]
ffff88811e7e81e0 (&dev->mutex){....}-{4:4}, at: manufacturer_show+0x26/0xa0 drivers/usb/core/sysfs.c:142
7 locks held by kworker/1:3/5224:
11 locks held by kworker/1:5/5231:
4 locks held by udevd/5240:
#0: ffff88811c9378b8 (&p->lock){+.+.}-{4:4}, at: seq_read_iter+0xe1/0x1270 fs/seq_file.c:183
#1: ffff88811c91d888 (&of->mutex#2){+.+.}-{4:4}, at: kernfs_seq_start+0x4f/0x2a0 fs/kernfs/file.c:172
#2:
ffff888114e720f8 (kn->active#20){++++}-{0:0}, at: kernfs_get_active_of fs/kernfs/file.c:80 [inline]
ffff888114e720f8 (kn->active#20){++++}-{0:0}, at: kernfs_seq_start+0xbc/0x2a0 fs/kernfs/file.c:173
#3: ffff888105a891e0 (&dev->mutex){....}-{4:4}, at: device_lock_interruptible include/linux/device.h:954 [inline]
#3: ffff888105a891e0 (&dev->mutex){....}-{4:4}, at: manufacturer_show+0x26/0xa0 drivers/usb/core/sysfs.c:142
4 locks held by udevd/5322:
#0: ffff888120e6e668 (&p->lock){+.+.}-{4:4}, at: seq_read_iter+0xe1/0x1270 fs/seq_file.c:183
#1: ffff888124491088 (&of->mutex#2){+.+.}-{4:4}, at: kernfs_seq_start+0x4f/0x2a0 fs/kernfs/file.c:172
#2:
ffff888114d710f8
(kn->active#20){++++}-{0:0}, at: kernfs_get_active_of fs/kernfs/file.c:80 [inline]
(kn->active#20){++++}-{0:0}, at: kernfs_seq_start+0xbc/0x2a0 fs/kernfs/file.c:173
#3: ffff888132f111e0 (&dev->mutex){....}-{4:4}, at: device_lock_interruptible include/linux/device.h:954 [inline]
#3: ffff888132f111e0 (&dev->mutex){....}-{4:4}, at: manufacturer_show+0x26/0xa0 drivers/usb/core/sysfs.c:142
=============================================
NMI backtrace for cpu 0
CPU: 0 UID: 0 PID: 30 Comm: khungtaskd Not tainted syzkaller #0 PREEMPT(full)
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 03/18/2026
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:113
nmi_trigger_cpumask_backtrace+0x1d7/0x230 lib/nmi_backtrace.c:62
trigger_all_cpu_backtrace include/linux/nmi.h:161 [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:346 [inline]
watchdog+0xd25/0x1050 kernel/hung_task.c:515
kthread+0x370/0x450 kernel/kthread.c:436
ret_from_fork+0x6c3/0xcb0 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: 5231 Comm: kworker/1:5 Not tainted syzkaller #0 PREEMPT(full)
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 03/18/2026
Workqueue: usb_hub_wq hub_event
RIP: 0010:io_serial_in+0x87/0xb0 drivers/tty/serial/8250/8250_port.c:402
Code: 75 91 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 e9 bd 43 4c 04 e8 28 78 f5 fe eb a2 e8 b1 78
RSP: 0018:ffffc900035ae2f8 EFLAGS: 00000002
RAX: dffffc0000000000 RBX: 00000000000003fd RCX: 0000000000000000
RDX: 00000000000003fd RSI: ffffffff832086f0 RDI: ffffffff941b8be0
RBP: ffffffff941b8ba0 R08: 0000000000000001 R09: 000000000000001f
R10: 0000000000000000 R11: 0000000000000000 R12: 0000000000000000
R13: 0000000000000020 R14: fffffbfff28371ce R15: dffffc0000000000
FS: 0000000000000000(0000) GS:ffff8882687c9000(0000) knlGS:0000000000000000
CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 000055557be26908 CR3: 000000011bcd8000 CR4: 00000000003506f0
Call Trace:
serial_in drivers/tty/serial/8250/8250.h:128 [inline]
serial_lsr_in drivers/tty/serial/8250/8250.h:150 [inline]
wait_for_lsr+0x13a/0x210 drivers/tty/serial/8250/8250_port.c:1970
serial8250_fifo_wait_for_lsr_thre drivers/tty/serial/8250/8250_port.c:3207 [inline]
serial8250_console_fifo_write drivers/tty/serial/8250/8250_port.c:3272 [inline]
serial8250_console_write+0xdb9/0x1900 drivers/tty/serial/8250/8250_port.c:3357
console_emit_next_record kernel/printk/printk.c:3183 [inline]
console_flush_one_record+0x790/0xe50 kernel/printk/printk.c:3269
console_flush_all kernel/printk/printk.c:3343 [inline]
__console_flush_and_unlock kernel/printk/printk.c:3373 [inline]
console_unlock+0x103/0x260 kernel/printk/printk.c:3413
vprintk_emit+0x407/0x6b0 kernel/printk/printk.c:2479
dev_vprintk_emit+0x394/0x3e0 drivers/base/core.c:4915
dev_printk_emit+0xd2/0x10d drivers/base/core.c:4926
__dev_printk+0xcb/0x100 drivers/base/core.c:4938
_dev_err+0xef/0x127 drivers/base/core.c:4981
parse_uac2_sample_rate_range.cold+0x100/0x135 sound/usb/format.c:468
parse_audio_format_rates_v2v3+0x2fe/0xf70 sound/usb/format.c:689
parse_audio_format_ii sound/usb/format.c:847 [inline]
snd_usb_parse_audio_format.cold+0x48c/0x4cc sound/usb/format.c:868
snd_usb_get_audioformat_uac12 sound/usb/stream.c:856 [inline]
__snd_usb_parse_audio_interface+0xa85/0x4710 sound/usb/stream.c:1201
snd_usb_parse_audio_interface+0x81/0x110 sound/usb/stream.c:1282
create_standard_audio_quirk+0x6b/0x120 sound/usb/quirks.c:101
snd_usb_create_quirk sound/usb/quirks.c:541 [inline]
create_composite_quirk+0x257/0x510 sound/usb/quirks.c:49
snd_usb_create_quirk+0xad/0xf0 sound/usb/quirks.c:541
usb_audio_probe+0x992/0x3a90 sound/usb/card.c:1023
usb_probe_interface+0x303/0x8f0 drivers/usb/core/driver.c:396
call_driver_probe drivers/base/dd.c:643 [inline]
really_probe+0x241/0xa60 drivers/base/dd.c:721
__driver_probe_device+0x1de/0x400 drivers/base/dd.c:863
driver_probe_device+0x4c/0x1b0 drivers/base/dd.c:893
__device_attach_driver+0x1df/0x340 drivers/base/dd.c:1021
bus_for_each_drv+0x159/0x1e0 drivers/base/bus.c:500
__device_attach+0x1e4/0x4d0 drivers/base/dd.c:1093
device_initial_probe+0xaf/0xd0 drivers/base/dd.c:1148
bus_probe_device+0x64/0x160 drivers/base/bus.c:613
device_add+0x11d9/0x1950 drivers/base/core.c:3691
usb_set_configuration+0xd97/0x1c60 drivers/usb/core/message.c:2268
usb_generic_driver_probe+0xa1/0xe0 drivers/usb/core/generic.c:250
usb_probe_device+0xef/0x400 drivers/usb/core/driver.c:291
call_driver_probe drivers/base/dd.c:643 [inline]
really_probe+0x241/0xa60 drivers/base/dd.c:721
__driver_probe_device+0x1de/0x400 drivers/base/dd.c:863
driver_probe_device+0x4c/0x1b0 drivers/base/dd.c:893
__device_attach_driver+0x1df/0x340 drivers/base/dd.c:1021
bus_for_each_drv+0x159/0x1e0 drivers/base/bus.c:500
__device_attach+0x1e4/0x4d0 drivers/base/dd.c:1093
device_initial_probe+0xaf/0xd0 drivers/base/dd.c:1148
bus_probe_device+0x64/0x160 drivers/base/bus.c:613
device_add+0x11d9/0x1950 drivers/base/core.c:3691
usb_new_device.cold+0x685/0x115c drivers/usb/core/hub.c:2695
hub_port_connect drivers/usb/core/hub.c:5567 [inline]
hub_port_connect_change drivers/usb/core/hub.c:5707 [inline]
port_event drivers/usb/core/hub.c:5871 [inline]
hub_event+0x314d/0x4af0 drivers/usb/core/hub.c:5953
process_one_work+0xa23/0x19a0 kernel/workqueue.c:3276
process_scheduled_works kernel/workqueue.c:3359 [inline]
worker_thread+0x5ef/0xe50 kernel/workqueue.c:3440
kthread+0x370/0x450 kernel/kthread.c:436
ret_from_fork+0x6c3/0xcb0 arch/x86/kernel/process.c:158
ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:245