INFO: task udevd:2856 blocked for more than 143 seconds.
Not tainted syzkaller #0
"echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message.
task:udevd state:D stack:26840 pid:2856 tgid:2856 ppid:1 task_flags:0x400140 flags:0x00080001
Call Trace:
context_switch kernel/sched/core.c:5325 [inline]
__schedule+0x12fc/0x3b80 kernel/sched/core.c:6929
__schedule_loop kernel/sched/core.c:7011 [inline]
schedule+0xe7/0x3a0 kernel/sched/core.c:7026
schedule_preempt_disabled+0x13/0x30 kernel/sched/core.c:7083
rwsem_down_read_slowpath+0x64b/0xbf0 kernel/locking/rwsem.c:1086
__down_read_common kernel/locking/rwsem.c:1261 [inline]
__down_read kernel/locking/rwsem.c:1274 [inline]
down_read+0xef/0x480 kernel/locking/rwsem.c:1539
kernfs_dop_revalidate+0xa5/0x740 fs/kernfs/dir.c:1180
d_revalidate fs/namei.c:929 [inline]
d_revalidate fs/namei.c:925 [inline]
lookup_fast+0x266/0x610 fs/namei.c:1777
walk_component+0x5b/0x5b0 fs/namei.c:2147
link_path_walk+0x627/0xe20 fs/namei.c:2519
path_lookupat+0x15a/0x6d0 fs/namei.c:2675
filename_lookup+0x224/0x5f0 fs/namei.c:2705
do_readlinkat+0xce/0x3a0 fs/stat.c:576
__do_sys_readlink fs/stat.c:613 [inline]
__se_sys_readlink fs/stat.c:610 [inline]
__x64_sys_readlink+0x78/0xc0 fs/stat.c:610
do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline]
do_syscall_64+0xcd/0x4d0 arch/x86/entry/syscall_64.c:94
entry_SYSCALL_64_after_hwframe+0x77/0x7f
RIP: 0033:0x7f216521a3a7
RSP: 002b:00007ffe68ff4a18 EFLAGS: 00000246
ORIG_RAX: 0000000000000059
RAX: ffffffffffffffda RBX: 00007ffe68ff4ef0 RCX: 00007f216521a3a7
RDX: 0000000000000400 RSI: 00007ffe68ff4a20 RDI: 00007ffe68ff4ef0
RBP: 00007ffe68ff4a20 R08: 0000000000000075 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000400
R13: 0000563363c71100 R14: 0000000000000001 R15: 00007ffe68ff67f0
INFO: task syz.3.15:5261 blocked for more than 143 seconds.
Not tainted syzkaller #0
"echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message.
task:syz.3.15 state:D
stack:28104 pid:5261 tgid:5260 ppid:2973 task_flags:0x400040 flags:0x00080002
Call Trace:
context_switch kernel/sched/core.c:5325 [inline]
__schedule+0x12fc/0x3b80 kernel/sched/core.c:6929
__schedule_loop kernel/sched/core.c:7011 [inline]
schedule+0xe7/0x3a0 kernel/sched/core.c:7026
schedule_preempt_disabled+0x13/0x30 kernel/sched/core.c:7083
rwsem_down_write_slowpath+0x521/0x1310 kernel/locking/rwsem.c:1185
__down_write_common kernel/locking/rwsem.c:1317 [inline]
__down_write kernel/locking/rwsem.c:1326 [inline]
down_write+0x1d6/0x200 kernel/locking/rwsem.c:1591
kernfs_add_one+0x38/0x840 fs/kernfs/dir.c:791
kernfs_create_dir_ns+0xfc/0x1a0 fs/kernfs/dir.c:1093
sysfs_create_dir_ns+0x13a/0x2b0 fs/sysfs/dir.c:59
create_dir lib/kobject.c:73 [inline]
kobject_add_internal+0x2c4/0x9b0 lib/kobject.c:240
kobject_add_varg lib/kobject.c:374 [inline]
kobject_init_and_add+0x11b/0x190 lib/kobject.c:457
bus_add_driver+0x186/0x690 drivers/base/bus.c:671
driver_register+0x15c/0x4b0 drivers/base/driver.c:249
usb_gadget_register_driver_owner+0x132/0x330 drivers/usb/gadget/udc/core.c:1704
raw_ioctl_run drivers/usb/gadget/legacy/raw_gadget.c:595 [inline]
raw_ioctl+0x17d0/0x2c30 drivers/usb/gadget/legacy/raw_gadget.c:1306
vfs_ioctl fs/ioctl.c:51 [inline]
__do_sys_ioctl fs/ioctl.c:597 [inline]
__se_sys_ioctl fs/ioctl.c:583 [inline]
__x64_sys_ioctl+0x18b/0x210 fs/ioctl.c:583
do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline]
do_syscall_64+0xcd/0x4d0 arch/x86/entry/syscall_64.c:94
entry_SYSCALL_64_after_hwframe+0x77/0x7f
RIP: 0033:0x7fd556c6eacb
RSP: 002b:00007fd5556d4f10 EFLAGS: 00000246
ORIG_RAX: 0000000000000010
RAX: ffffffffffffffda RBX: 0000000000000003 RCX: 00007fd556c6eacb
RDX: 0000000000000000 RSI: 0000000000005501 RDI: 0000000000000003
RBP: 00007fd5556d5fe0 R08: 0000000000000000 R09: 00332e6364755f79
R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000
R13: 00007fd5556d4fb0 R14: 0000200000000dc0 R15: 00007fd556ff0320
Showing all locks held in the system:
5 locks held by kworker/1:0/23:
1 lock held by khungtaskd/30:
#0:
ffffffff892c89a0
(rcu_read_lock
){....}-{1:3}
, at: rcu_lock_acquire include/linux/rcupdate.h:331 [inline]
, at: rcu_read_lock include/linux/rcupdate.h:867 [inline]
, at: debug_show_all_locks+0x36/0x1c0 kernel/locking/lockdep.c:6775
6 locks held by kworker/1:1/44:
3 locks held by kworker/1:2/1120:
1 lock held by udevd/2856:
#0:
ffff888100ac5988 (
&root->kernfs_rwsem
){++++}-{4:4}
, at: kernfs_dop_revalidate+0xa5/0x740 fs/kernfs/dir.c:1180
2 locks held by getty/2918:
#0:
ffff88810be9d0a0
(&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+0x41b/0x14f0 drivers/tty/n_tty.c:2222
1 lock held by syz-executor/2965:
#0:
ffff888100ac5988
(&root->kernfs_rwsem
){++++}-{4:4}
, at: kernfs_dop_revalidate+0x397/0x740 fs/kernfs/dir.c:1162
1 lock held by syz-executor/2966:
#0: ffff888100ac5988
(
&root->kernfs_rwsem
){++++}-{4:4}
, at: kernfs_dop_revalidate+0x397/0x740 fs/kernfs/dir.c:1162
1 lock held by syz-executor/2967:
#0:
ffff888100ac5988
(
&root->kernfs_rwsem
){++++}-{4:4}
, at: kernfs_dop_revalidate+0x397/0x740 fs/kernfs/dir.c:1162
1 lock held by syz-executor/2971:
#0:
ffff888100ac5988 (
&root->kernfs_rwsem
){++++}-{4:4}
, at: kernfs_dop_revalidate+0x397/0x740 fs/kernfs/dir.c:1162
1 lock held by syz-executor/2973:
#0:
ffff888100ac5988
(&root->kernfs_rwsem
){++++}-{4:4}
, at: kernfs_dop_revalidate+0x397/0x740 fs/kernfs/dir.c:1162
4 locks held by kworker/0:4/5224:
#0: ffff8881072e9948
(
(wq_completion)usb_hub_wq
){+.+.}-{0:0}
, at: process_one_work+0x12a2/0x1b70 kernel/workqueue.c:3238
#1:
ffffc900022cfd10
(
(work_completion)(&hub->events)
){+.+.}-{0:0}
, at: process_one_work+0x929/0x1b70 kernel/workqueue.c:3239
#2:
ffff88810b7aa198
(&dev->mutex
){....}-{4:4}
, at: device_lock include/linux/device.h:914 [inline]
, at: hub_event+0x1be/0x5060 drivers/usb/core/hub.c:5898
#3:
ffff888100ac5988 (
&root->kernfs_rwsem
){++++}-{4:4}
, at: kernfs_activate fs/kernfs/dir.c:1425 [inline]
, at: kernfs_add_one+0x349/0x840 fs/kernfs/dir.c:834
5 locks held by kworker/1:4/5228:
#0:
ffff8881072e9948
((wq_completion)usb_hub_wq
){+.+.}-{0:0}
, at: process_one_work+0x12a2/0x1b70 kernel/workqueue.c:3238
#1: ffffc9000223fd10
(
(work_completion)(&hub->events)
){+.+.}-{0:0}
, at: process_one_work+0x929/0x1b70 kernel/workqueue.c:3239
#2: ffff88810b70d198
(&dev->mutex){....}-{4:4}
, at: device_lock include/linux/device.h:914 [inline]
, at: hub_event+0x1be/0x5060 drivers/usb/core/hub.c:5898
#3: ffff8881170e1198 (&dev->mutex){....}-{4:4}, at: device_lock include/linux/device.h:914 [inline]
#3: ffff8881170e1198 (&dev->mutex){....}-{4:4}, at: __device_attach+0x7e/0x4b0 drivers/base/dd.c:1006
#4:
ffff888100ac5988
(&root->kernfs_rwsem
){++++}-{4:4}
, at: kernfs_add_one+0x38/0x840 fs/kernfs/dir.c:791
4 locks held by kworker/1:5/5233:
#0: ffff888100071948
(
(wq_completion)events
){+.+.}-{0:0}
, at: process_one_work+0x12a2/0x1b70 kernel/workqueue.c:3238
#1:
ffffc9000225fd10
(kernfs_notify_work
){+.+.}-{0:0}
, at: process_one_work+0x929/0x1b70 kernel/workqueue.c:3239
#2: ffff888100ac5ab8
(
&root->kernfs_supers_rwsem
){++++}-{4:4}
, at: kernfs_notify_workfn+0xf7/0xb30 fs/kernfs/file.c:932
#3:
ffff888100ac5988
(&root->kernfs_rwsem
){++++}-{4:4}
, at: kernfs_notify_workfn+0xff/0xb30 fs/kernfs/file.c:933
1 lock held by syz.0.10/5249:
#0: ffff888100ac5988
(
&root->kernfs_rwsem
){++++}-{4:4}
, at: kernfs_remove_by_name_ns+0x3d/0x110 fs/kernfs/dir.c:1712
1 lock held by syz.2.12/5252:
#0: ffff888100ac5988
(&root->kernfs_rwsem
){++++}-{4:4}
, at: kernfs_remove_by_name_ns+0x3d/0x110 fs/kernfs/dir.c:1712
4 locks held by udevd/5253:
#0:
ffff888136e37418
(&p->lock
){+.+.}-{4:4}
, at: seq_read_iter+0xe1/0x12d0 fs/seq_file.c:182
#1:
ffff888136fad488 (
&of->mutex
#2
){+.+.}-{4:4}
, at: kernfs_seq_start+0x4f/0x2a0 fs/kernfs/file.c:172
#2:
ffff88813691fc38
(kn->active
#14
){.+.+}-{0:0}
, at: kernfs_get_active_of fs/kernfs/file.c:80 [inline]
, at: kernfs_seq_start+0xbc/0x2a0 fs/kernfs/file.c:173
#3: ffff8881170e1198
(
&dev->mutex
){....}-{4:4}
, at: device_lock_interruptible include/linux/device.h:919 [inline]
, at: manufacturer_show+0x26/0xa0 drivers/usb/core/sysfs.c:142
1 lock held by syz.4.13/5254:
#0: ffff888100ac5988
(
&root->kernfs_rwsem
){++++}-{4:4}
, at: kernfs_remove_by_name_ns+0x3d/0x110 fs/kernfs/dir.c:1712
1 lock held by syz.1.14/5259:
#0:
ffff888100ac5988 (
&root->kernfs_rwsem
){++++}-{4:4}
, at: kernfs_remove_by_name_ns+0x3d/0x110 fs/kernfs/dir.c:1712
1 lock held by syz-executor/5262:
#0:
ffff888100ac5988
(&root->kernfs_rwsem
){++++}-{4:4}
, at: kernfs_dop_revalidate+0xa5/0x740 fs/kernfs/dir.c:1180
1 lock held by syz-executor/5263:
#0: ffff888100ac5988
(
&root->kernfs_rwsem
){++++}-{4:4}
, at: kernfs_dop_revalidate+0xa5/0x740 fs/kernfs/dir.c:1180
1 lock held by syz-executor/5264:
#0:
ffff888100ac5988 (
&root->kernfs_rwsem
){++++}-{4:4}
, at: kernfs_dop_revalidate+0xa5/0x740 fs/kernfs/dir.c:1180
1 lock held by syz-executor/5265:
#0:
ffff888100ac5988
(&root->kernfs_rwsem
){++++}-{4:4}
, at: kernfs_dop_revalidate+0xa5/0x740 fs/kernfs/dir.c:1180
1 lock held by syz-executor/5266:
#0: ffff888100ac5988
(
&root->kernfs_rwsem
){++++}-{4:4}
, at: kernfs_dop_revalidate+0xa5/0x740 fs/kernfs/dir.c:1180
=============================================
NMI backtrace for cpu 0
CPU: 0 UID: 0 PID: 30 Comm: khungtaskd Not tainted syzkaller #0 PREEMPT(voluntary)
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 08/18/2025
Call Trace:
__dump_stack lib/dump_stack.c:94 [inline]
dump_stack_lvl+0x116/0x1f0 lib/dump_stack.c:120
nmi_cpu_backtrace+0x27b/0x390 lib/nmi_backtrace.c:113
nmi_trigger_cpumask_backtrace+0x29c/0x300 lib/nmi_backtrace.c:62
trigger_all_cpu_backtrace include/linux/nmi.h:160 [inline]
check_hung_uninterruptible_tasks kernel/hung_task.c:332 [inline]
watchdog+0xf3f/0x1170 kernel/hung_task.c:495
kthread+0x3c5/0x780 kernel/kthread.c:463
ret_from_fork+0x56a/0x700 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:
yealink 4-1:36.0: urb_irq_callback - urb status -71
NMI backtrace for cpu 1
CPU: 1 UID: 0 PID: 5249 Comm: syz.0.10 Not tainted syzkaller #0 PREEMPT(voluntary)
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 08/18/2025
RIP: 0010:io_serial_in+0x87/0xb0 drivers/tty/serial/8250/8250_port.c:401
Code: c6 a0 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 5d 69 04 e8 f8 e5 00 ff eb a2 e8 81 e6
RSP: 0018:ffffc900001a84f8 EFLAGS: 00000006
RAX: dffffc0000000005 RBX: 00000000000003f9 RCX: 0000000000000000
RDX: 00000000000003f9 RSI: ffffffff82dd8f30 RDI: ffffffff93bd65c0
RBP: ffffffff93bd6580 R08: 0000000000000001 R09: 000000000000001f
R10: 0000000000000000 R11: 0000000000000000 R12: 0000000000000000
R13: ffffffff93bd65d0 R14: ffffffff93bd6580 R15: ffffffff93bd6840
FS: 0000000000000000(0000) GS:ffff888268fa6000(0000) knlGS:0000000000000000
CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 00007f49285821e0 CR3: 000000011aa60000 CR4: 00000000003506f0
Call Trace:
serial_port_in include/linux/serial_core.h:806 [inline]
serial8250_console_write+0x246/0x1890 drivers/tty/serial/8250/8250_port.c:3306
console_emit_next_record kernel/printk/printk.c:3111 [inline]
console_flush_all+0x801/0xc60 kernel/printk/printk.c:3199
__console_flush_and_unlock kernel/printk/printk.c:3258 [inline]
console_unlock+0xd8/0x210 kernel/printk/printk.c:3298
vprintk_emit+0x3d7/0x680 kernel/printk/printk.c:2423
dev_vprintk_emit drivers/base/core.c:4914 [inline]
dev_printk_emit+0xfa/0x140 drivers/base/core.c:4925
__dev_printk+0xf5/0x270 drivers/base/core.c:4937
_dev_err+0xe4/0x120 drivers/base/core.c:4980
urb_irq_callback+0x454/0x700 drivers/input/misc/yealink.c:418
__usb_hcd_giveback_urb+0x38b/0x610 drivers/usb/core/hcd.c:1661
usb_hcd_giveback_urb+0x39b/0x450 drivers/usb/core/hcd.c:1745
dummy_timer+0x1809/0x3a00 drivers/usb/gadget/udc/dummy_hcd.c:1995
__run_hrtimer kernel/time/hrtimer.c:1777 [inline]
__hrtimer_run_queues+0x1ff/0xad0 kernel/time/hrtimer.c:1841
hrtimer_run_softirq+0x17d/0x350 kernel/time/hrtimer.c:1858
handle_softirqs+0x205/0x8d0 kernel/softirq.c:622
__do_softirq kernel/softirq.c:656 [inline]
invoke_softirq kernel/softirq.c:496 [inline]
__irq_exit_rcu+0xfa/0x160 kernel/softirq.c:723
irq_exit_rcu+0x9/0x30 kernel/softirq.c:739
instr_sysvec_apic_timer_interrupt arch/x86/kernel/apic/apic.c:1052 [inline]
sysvec_apic_timer_interrupt+0x90/0xb0 arch/x86/kernel/apic/apic.c:1052
asm_sysvec_apic_timer_interrupt+0x1a/0x20 arch/x86/include/asm/idtentry.h:702
RIP: 0010:rcu_preempt_read_exit kernel/rcu/tree_plugin.h:396 [inline]
RIP: 0010:__rcu_read_unlock+0x3d/0x550 kernel/rcu/tree_plugin.h:435
Code: 53 48 8d bd fc 03 00 00 48 b8 00 00 00 00 00 fc ff df 48 89 fa 48 c1 ea 03 0f b6 14 02 48 89 f8 83 e0 07 83 c0 03 38 d0 7c 08 <84> d2 0f 85 4a 02 00 00 65 4c 8b 25 4b b8 32 0b 49 8d bc 24 fc 03
RSP: 0018:ffffc9000209f8e8 EFLAGS: 00000202
RAX: 0000000000000007 RBX: 0000000000000001 RCX: ffffc9000209f8dc
RDX: 0000000000000000 RSI: ffffffff88c66b09 RDI: ffff888121fb5afc
RBP: ffff888121fb5700 R08: 0000000000000001 R09: 0000000000000000
R10: 0000000000000001 R11: 0000000000000000 R12: 0000000000000001
R13: ffff888136b17b40 R14: 0000000000000000 R15: 0000000000000001
rcu_read_unlock include/linux/rcupdate.h:899 [inline]
class_rcu_destructor include/linux/rcupdate.h:1195 [inline]
kernfs_root+0xf8/0x2a0 fs/kernfs/kernfs-internal.h:75
__kernfs_remove+0x302/0x8a0 fs/kernfs/dir.c:1519
kernfs_remove_by_name_ns+0x68/0x110 fs/kernfs/dir.c:1717
driver_sysfs_remove drivers/base/dd.c:476 [inline]
__device_release_driver drivers/base/dd.c:1268 [inline]
device_release_driver_internal+0x415/0x620 drivers/base/dd.c:1297
driver_detach+0xd8/0x1b0 drivers/base/dd.c:1360
bus_remove_driver+0x13b/0x2c0 drivers/base/bus.c:747
driver_unregister+0x76/0xb0 drivers/base/driver.c:277
usb_gadget_unregister_driver+0x49/0x70 drivers/usb/gadget/udc/core.c:1736
raw_release+0x1ae/0x2b0 drivers/usb/gadget/legacy/raw_gadget.c:462
__fput+0x402/0xb70 fs/file_table.c:468
task_work_run+0x150/0x240 kernel/task_work.c:227
exit_task_work include/linux/task_work.h:40 [inline]
do_exit+0x86f/0x2bf0 kernel/exit.c:966
do_group_exit+0xd3/0x2a0 kernel/exit.c:1107
get_signal+0x2671/0x26d0 kernel/signal.c:3034
arch_do_signal_or_restart+0x8f/0x7c0 arch/x86/kernel/signal.c:337
exit_to_user_mode_loop+0x76/0xe0 kernel/entry/common.c:40
exit_to_user_mode_prepare include/linux/irq-entry-common.h:225 [inline]
syscall_exit_to_user_mode_work include/linux/entry-common.h:175 [inline]
syscall_exit_to_user_mode include/linux/entry-common.h:210 [inline]
do_syscall_64+0x40f/0x4d0 arch/x86/entry/syscall_64.c:100
entry_SYSCALL_64_after_hwframe+0x77/0x7f
RIP: 0033:0x7f417ca7eacb
Code: Unable to access opcode bytes at 0x7f417ca7eaa1.
RSP: 002b:00007f417b4dcf10 EFLAGS: 00000246 ORIG_RAX: 0000000000000010
RAX: fffffffffffffffc RBX: 0000000000000005 RCX: 00007f417ca7eacb
RDX: 00007f417b4ddfe0 RSI: 0000000080085502 RDI: 0000000000000005
RBP: 00007f417b4ddfe0 R08: 0000000000000080 R09: 00007f417b4dcfd8
R10: 0000000000000000 R11: 0000000000000246 R12: 0000000080085502
R13: 0000000800000000 R14: 000000000000001b R15: 00007f417cb0d50d