INFO: task udevd:2860 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:26776 pid:2860 tgid:2860 ppid:1 task_flags:0x400140 flags:0x00080000
Call Trace:
context_switch kernel/sched/core.c:5260 [inline]
__schedule+0xeb0/0x3e50 kernel/sched/core.c:6867
__schedule_loop kernel/sched/core.c:6949 [inline]
schedule+0xdd/0x390 kernel/sched/core.c:6964
schedule_preempt_disabled+0x13/0x30 kernel/sched/core.c:7021
rwsem_down_read_slowpath+0x5dc/0xb30 kernel/locking/rwsem.c:1086
__down_read_common kernel/locking/rwsem.c:1261 [inline]
__down_read kernel/locking/rwsem.c:1274 [inline]
down_read+0xed/0x460 kernel/locking/rwsem.c:1539
kernfs_dop_revalidate+0xa5/0x740 fs/kernfs/dir.c:1185
d_revalidate fs/namei.c:977 [inline]
d_revalidate fs/namei.c:973 [inline]
lookup_fast+0x3c7/0x600 fs/namei.c:1827
walk_component fs/namei.c:2225 [inline]
link_path_walk+0x7a8/0x1b30 fs/namei.c:2597
path_lookupat+0x74/0xc40 fs/namei.c:2753
filename_lookup+0x202/0x590 fs/namei.c:2783
do_readlinkat+0xd1/0x390 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+0xc9/0x570 arch/x86/entry/syscall_64.c:94
entry_SYSCALL_64_after_hwframe+0x77/0x7f
RIP: 0033:0x7f6b506503a7
RSP: 002b:00007fff84e038c8 EFLAGS: 00000246
ORIG_RAX: 0000000000000059
RAX: ffffffffffffffda RBX: 00007fff84e03da0 RCX: 00007f6b506503a7
RDX: 0000000000000400 RSI: 00007fff84e038d0 RDI: 00007fff84e03da0
RBP: 00007fff84e038d0 R08: 0000000000000075 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000400
R13: 000055e811332100 R14: 0000000000000001 R15: 00007fff84e056a0
Showing all locks held in the system:
4 locks held by kworker/1:0/23:
#0: ffff8881052fd548
(
(wq_completion)usb_hub_wq
){+.+.}-{0:0}
, at: process_one_work+0x11ae/0x1840 kernel/workqueue.c:3232
#1:
ffffc9000018fca8
((work_completion)(&hub->events)
){+.+.}-{0:0}
, at: process_one_work+0x927/0x1840 kernel/workqueue.c:3233
#2: ffff88810a738198
(
&dev->mutex
){....}-{4:4}
, at: device_lock include/linux/device.h:895 [inline]
, at: hub_event+0x1bd/0x4af0 drivers/usb/core/hub.c:5899
#3:
ffff888100ac5988
(&root->kernfs_rwsem
){++++}-{4:4}
, at: kernfs_add_one+0x38/0x850 fs/kernfs/dir.c:796
1 lock held by khungtaskd/30:
#0:
ffffffff894da3a0
(
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+0x3d/0x184 kernel/locking/lockdep.c:6775
5 locks held by kworker/1:1/42:
2 locks held by kworker/u8:3/48:
2 locks held by kworker/u8:8/346:
6 locks held by kworker/1:2/1121:
1 lock held by udevd/2860:
#0:
ffff888100ac5988
(
&root->kernfs_rwsem
){++++}-{4:4}, at: kernfs_dop_revalidate+0xa5/0x740 fs/kernfs/dir.c:1185
2 locks held by getty/2922:
#0: ffff8881128450a0 (&tty->ldisc_sem){++++}-{0:0}
, at: tty_ldisc_ref_wait+0x24/0x80 drivers/tty/tty_ldisc.c:243
#1: ffffc900000452f0 (&ldata->atomic_read_lock){+.+.}-{4:4}, at: n_tty_read+0x419/0x1500 drivers/tty/n_tty.c:2211
1 lock held by syz-executor/2968:
1 lock held by syz-executor/2969:
1 lock held by syz-executor/2970:
#0:
ffffffff894e6b78
(
rcu_state.exp_mutex){+.+.}-{4:4}
, at: exp_funnel_lock+0x27f/0x3c0 kernel/rcu/tree_exp.h:311
8 locks held by syz-executor/2973:
1 lock held by syz.1.65/5445:
#0:
ffff888100ac5988
(
&root->kernfs_rwsem){++++}-{4:4}
, at: kernfs_remove_by_name_ns+0x3d/0xf0 fs/kernfs/dir.c:1717
1 lock held by syz.4.67/5449:
#0: ffff888100ac5988
(&root->kernfs_rwsem
){++++}-{4:4}
, at: kernfs_remove_by_name_ns+0x3d/0xf0 fs/kernfs/dir.c:1717
1 lock held by syz.2.68/5451:
#0:
ffff888100ac5988
(&root->kernfs_rwsem
){++++}-{4:4}
, at: kernfs_remove_by_name_ns+0x3d/0xf0 fs/kernfs/dir.c:1717
1 lock held by syz-executor/5454:
1 lock held by syz-executor/5455:
#0:
ffff888100ac5988
(&root->kernfs_rwsem
){++++}-{4:4}
, at: kernfs_dop_revalidate+0xa5/0x740 fs/kernfs/dir.c:1185
1 lock held by syz-executor/5456:
#0: ffff888100ac5988
(
&root->kernfs_rwsem
){++++}-{4:4}
, at: kernfs_dop_revalidate+0xa5/0x740 fs/kernfs/dir.c:1185
=============================================
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 01/24/2026
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+0xcc3/0xfe0 kernel/hung_task.c:515
kthread+0x3b3/0x730 kernel/kthread.c:463
ret_from_fork+0x6c3/0xa20 arch/x86/kernel/process.c:158
ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:246
Sending NMI from CPU 0 to CPUs 1:
yealink 3-1:36.0: unexpected response 0
yealink 3-1:36.0: urb_ctl_callback - urb status -71
NMI backtrace for cpu 1
CPU: 1 UID: 0 PID: 42 Comm: kworker/1:1 Not tainted syzkaller #0 PREEMPT(voluntary)
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/24/2026
Workqueue: usb_hub_wq hub_event
RIP: 0010:io_serial_out+0x8f/0xb0 drivers/tty/serial/8250/8250_port.c:407
Code: 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 1c 66 03 5d 40 44 89 e8 89 da ee <5b> 5d 41 5c 41 5d c3 cc cc cc cc e8 d1 6a 01 ff eb a0 e8 5a 6b 01
RSP: 0018:ffffc900001a8470 EFLAGS: 00000002
RAX: 000000000000005b RBX: 00000000000003f8 RCX: 0000000000000000
RDX: 00000000000003f8 RSI: ffffffff8311c005 RDI: ffffffff93f14fc0
RBP: ffffffff93f14f80 R08: 0000000000000001 R09: 000000000000001f
R10: 0000000000000000 R11: 0000000000000000 R12: 0000000000000000
R13: 000000000000005b R14: 0000000000000010 R15: ffffffff8311bfa0
FS: 0000000000000000(0000) GS:ffff888268a6a000(0000) knlGS:0000000000000000
CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 00007f6c9fcf08c0 CR3: 000000012fea2000 CR4: 00000000003506f0
Call Trace:
serial_port_out include/linux/serial_core.h:811 [inline]
serial8250_console_putchar drivers/tty/serial/8250/8250_port.c:3192 [inline]
serial8250_console_fifo_write drivers/tty/serial/8250/8250_port.c:3264 [inline]
serial8250_console_write+0xde8/0x1900 drivers/tty/serial/8250/8250_port.c:3342
console_emit_next_record kernel/printk/printk.c:3129 [inline]
console_flush_one_record+0x790/0xe50 kernel/printk/printk.c:3215
console_flush_all kernel/printk/printk.c:3289 [inline]
__console_flush_and_unlock kernel/printk/printk.c:3319 [inline]
console_unlock+0x103/0x260 kernel/printk/printk.c:3359
vprintk_emit+0x407/0x6b0 kernel/printk/printk.c:2426
dev_vprintk_emit+0x394/0x3e0 drivers/base/core.c:4914
dev_printk_emit+0xd2/0x10d drivers/base/core.c:4925
__dev_printk+0xcb/0x100 drivers/base/core.c:4937
_dev_err+0xef/0x127 drivers/base/core.c:4980
urb_ctl_callback.cold+0x41/0x8c drivers/input/misc/yealink.c:456
__usb_hcd_giveback_urb+0x38d/0x610 drivers/usb/core/hcd.c:1657
usb_hcd_giveback_urb+0x3ca/0x4a0 drivers/usb/core/hcd.c:1741
dummy_timer+0xd85/0x3670 drivers/usb/gadget/udc/dummy_hcd.c:1995
__run_hrtimer kernel/time/hrtimer.c:1777 [inline]
__hrtimer_run_queues+0x516/0x990 kernel/time/hrtimer.c:1841
hrtimer_run_softirq+0x17d/0x350 kernel/time/hrtimer.c:1858
handle_softirqs+0x1dd/0x8f0 kernel/softirq.c:622
__do_softirq kernel/softirq.c:656 [inline]
invoke_softirq kernel/softirq.c:496 [inline]
__irq_exit_rcu+0xed/0x150 kernel/softirq.c:723
irq_exit_rcu+0x9/0x30 kernel/softirq.c:739
instr_sysvec_apic_timer_interrupt arch/x86/kernel/apic/apic.c:1056 [inline]
sysvec_apic_timer_interrupt+0x8f/0xb0 arch/x86/kernel/apic/apic.c:1056
asm_sysvec_apic_timer_interrupt+0x1a/0x20 arch/x86/include/asm/idtentry.h:697
RIP: 0010:__raw_spin_unlock_irqrestore include/linux/spinlock_api_smp.h:152 [inline]
RIP: 0010:_raw_spin_unlock_irqrestore+0x31/0x80 kernel/locking/spinlock.c:194
Code: f5 53 48 8b 74 24 10 48 89 fb 48 83 c7 18 e8 06 01 38 fa 48 89 df e8 ee 4e 38 fa f7 c5 00 02 00 00 75 23 9c 58 f6 c4 02 75 37 01 00 00 00 e8 e5 d9 2b fa 65 8b 05 5e 30 75 05 85 c0 74 16 5b
RSP: 0018:ffffc900004d72f0 EFLAGS: 00000246
RAX: 0000000000000002 RBX: ffffffff8a0cf320 RCX: 0000000000000080
RDX: 0000000000000000 RSI: ffffffff88dec8eb RDI: ffffffff878e97a0
RBP: 0000000000000283 R08: 0000000000000001 R09: 0000000000000000
R10: 0000000000000001 R11: ffff8881f5739208 R12: 1ffff9200009ae66
R13: ffff88810a32b23c R14: ffff888108bdf600 R15: ffff888108bdf618
spin_unlock_irqrestore include/linux/spinlock.h:406 [inline]
usb_hcd_poll_rh_status+0x5c4/0x7e0 drivers/usb/core/hcd.c:758
dummy_hub_control+0x7d6/0x20c0 drivers/usb/gadget/udc/dummy_hcd.c:2371
rh_call_control drivers/usb/core/hcd.c:652 [inline]
rh_urb_enqueue drivers/usb/core/hcd.c:817 [inline]
usb_hcd_submit_urb+0xf08/0x2150 drivers/usb/core/hcd.c:1538
usb_submit_urb+0x8aa/0x1910 drivers/usb/core/urb.c:587
usb_start_wait_urb+0x106/0x4c0 drivers/usb/core/message.c:59
usb_internal_control_msg drivers/usb/core/message.c:103 [inline]
usb_control_msg+0x326/0x4a0 drivers/usb/core/message.c:154
set_port_feature drivers/usb/core/hub.c:466 [inline]
hub_port_reset+0x297/0x1c60 drivers/usb/core/hub.c:3083
hub_port_init+0x1f1/0x3810 drivers/usb/core/hub.c:4939
hub_port_connect drivers/usb/core/hub.c:5496 [inline]
hub_port_connect_change drivers/usb/core/hub.c:5707 [inline]
port_event drivers/usb/core/hub.c:5871 [inline]
hub_event+0x2f27/0x4af0 drivers/usb/core/hub.c:5953
process_one_work+0x9c2/0x1840 kernel/workqueue.c:3257
process_scheduled_works kernel/workqueue.c:3340 [inline]
worker_thread+0x5da/0xe40 kernel/workqueue.c:3421
kthread+0x3b3/0x730 kernel/kthread.c:463
ret_from_fork+0x6c3/0xa20 arch/x86/kernel/process.c:158
ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:246