INFO: task udevd:2840 blocked for more than 143 seconds.
Not tainted 6.16.0-rc7-syzkaller-g51d4b0a44c82 #0
"echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message.
task:udevd state:D
stack:24520 pid:2840 tgid:2840 ppid:1 task_flags:0x400140 flags:0x00004002
Call Trace:
context_switch kernel/sched/core.c:5397 [inline]
__schedule+0x1325/0x3b10 kernel/sched/core.c:6786
__schedule_loop kernel/sched/core.c:6864 [inline]
schedule+0xe7/0x3a0 kernel/sched/core.c:6879
schedule_preempt_disabled+0x13/0x30 kernel/sched/core.c:6936
rwsem_down_read_slowpath+0x62f/0xb60 kernel/locking/rwsem.c:1084
__down_read_common kernel/locking/rwsem.c:1248 [inline]
__down_read kernel/locking/rwsem.c:1261 [inline]
down_read+0xef/0x480 kernel/locking/rwsem.c:1526
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:1778
walk_component+0x5b/0x5b0 fs/namei.c:2134
link_path_walk+0x627/0xe20 fs/namei.c:2506
path_lookupat+0x15a/0x6d0 fs/namei.c:2662
filename_lookup+0x224/0x5f0 fs/namei.c:2692
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/0x4b0 arch/x86/entry/syscall_64.c:94
entry_SYSCALL_64_after_hwframe+0x77/0x7f
RIP: 0033:0x7f1068f663a7
RSP: 002b:00007fffda681768 EFLAGS: 00000246
ORIG_RAX: 0000000000000059
RAX: ffffffffffffffda RBX: 00007fffda681c40 RCX: 00007f1068f663a7
RDX: 0000000000000400 RSI: 00007fffda681770 RDI: 00007fffda681c40
RBP: 00007fffda681770 R08: 0000000000000075 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000400
R13: 000055d48c888100 R14: 0000000000000001 R15: 00007fffda683540
Showing all locks held in the system:
5 locks held by kauditd/29:
1 lock held by khungtaskd/30:
#0: ffffffff890c8440
(
rcu_read_lock){....}-{1:3}
, at: rcu_lock_acquire include/linux/rcupdate.h:331 [inline]
, at: rcu_read_lock include/linux/rcupdate.h:841 [inline]
, at: debug_show_all_locks+0x36/0x1c0 kernel/locking/lockdep.c:6770
6 locks held by kworker/1:1/37:
#0:
ffff8881066f3548
((wq_completion)usb_hub_wq
){+.+.}-{0:0}
, at: process_one_work+0x12a2/0x1b70 kernel/workqueue.c:3213
#1:
ffffc90000277d10
((work_completion)(&hub->events)
){+.+.}-{0:0}
, at: process_one_work+0x929/0x1b70 kernel/workqueue.c:3214
#2:
ffff88810b73d198 (&dev->mutex){....}-{4:4}
, at: console_trylock_spinning kernel/printk/printk.c:2061 [inline]
, at: vprintk_emit+0x57e/0x6d0 kernel/printk/printk.c:2449
#3: ffffffff890b5e70
(
console_srcu){....}-{0:0}
, at: debug_object_activate+0x14c/0x4c0 lib/debugobjects.c:818
#4: ffffffff88fd59c0
(
console_owner){..-.}-{0:0}
, at: rcu_lock_acquire include/linux/rcupdate.h:331 [inline]
, at: rcu_read_lock include/linux/rcupdate.h:841 [inline]
, at: class_rcu_constructor include/linux/rcupdate.h:1155 [inline]
, at: kernfs_root fs/kernfs/kernfs-internal.h:75 [inline]
, at: kernfs_notify_workfn+0x33a/0xb30 fs/kernfs/file.c:916
#5:
ffffffff88fd5978
(
console_owner_lock){-.-.}-{2:2}
, at: printk_legacy_allow_spinlock_enter kernel/printk/printk.c:3050 [inline]
, at: console_emit_next_record kernel/printk/printk.c:3137 [inline]
, at: console_flush_all+0x7bb/0xc60 kernel/printk/printk.c:3226
2 locks held by kworker/u8:2/38:
#0:
ffff888100089148 (
(wq_completion)events_unbound
){+.+.}-{0:0}
, at: process_one_work+0x12a2/0x1b70 kernel/workqueue.c:3213
#1: ffffc90000287d10
(
(reaper_work).work
){+.+.}-{0:0}
, at: process_one_work+0x929/0x1b70 kernel/workqueue.c:3214
2 locks held by kworker/u8:3/47:
#0: ffff888100089148
(
(wq_completion)events_unbound){+.+.}-{0:0}, at: process_one_work+0x12a2/0x1b70 kernel/workqueue.c:3213
#1:
ffffc90000527d10
(
(work_completion)(&sub_info->work)){+.+.}-{0:0}, at: process_one_work+0x929/0x1b70 kernel/workqueue.c:3214
4 locks held by kworker/u8:7/1999:
#0: ffff888100ac3948
(
(wq_completion)netns
){+.+.}-{0:0}
, at: process_one_work+0x12a2/0x1b70 kernel/workqueue.c:3213
#1:
ffffc90002c8fd10 (net_cleanup_work){+.+.}-{0:0}, at: process_one_work+0x929/0x1b70 kernel/workqueue.c:3214
#2:
ffffffff8a3c0d50
(
pernet_ops_rwsem){++++}-{4:4}, at: cleanup_net+0xad/0x890 net/core/net_namespace.c:662
#3:
ffffffff890d3a38
(
rcu_state.exp_mutex){+.+.}-{4:4}, at: exp_funnel_lock+0x1a3/0x3c0 kernel/rcu/tree_exp.h:336
2 locks held by getty/2902:
#0: ffff8881123440a0 (&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/2947:
#0: ffffffff890d3a38 (rcu_state.exp_mutex
){+.+.}-{4:4}
, at: exp_funnel_lock+0x1a3/0x3c0 kernel/rcu/tree_exp.h:336
4 locks held by udevd/5207:
#0: ffff888136d7b8b8
(
&p->lock){+.+.}-{4:4}, at: seq_read_iter+0xe1/0x12c0 fs/seq_file.c:182
#1: ffff88813872b088
(&of->mutex#2){+.+.}-{4:4}, at: kernfs_seq_start+0x4d/0x240 fs/kernfs/file.c:154
#2:
ffff888135094698 (kn->active
#21
){++++}-{0:0}, at: kernfs_seq_start+0x71/0x240 fs/kernfs/file.c:155
#3:
ffff888111ab2198
(
&dev->mutex){....}-{4:4}, at: device_lock_interruptible include/linux/device.h:889 [inline]
&dev->mutex){....}-{4:4}, at: manufacturer_show+0x26/0xa0 drivers/usb/core/sysfs.c:142
2 locks held by kworker/1:4/5239:
#0: ffff888100080d48 (
(wq_completion)events
){+.+.}-{0:0}
, at: process_one_work+0x12a2/0x1b70 kernel/workqueue.c:3213
#1:
ffffc9000389fd10
(free_ipc_work
){+.+.}-{0:0}
, at: process_one_work+0x929/0x1b70 kernel/workqueue.c:3214
6 locks held by kworker/1:5/5283:
#0: ffff8881066f3548
((wq_completion)usb_hub_wq
){+.+.}-{0:0}
, at: process_one_work+0x12a2/0x1b70 kernel/workqueue.c:3213
#1:
ffffc900039e7d10
(
(work_completion)(&hub->events)){+.+.}-{0:0}, at: process_one_work+0x929/0x1b70 kernel/workqueue.c:3214
#2:
ffff88810afef198
(
&dev->mutex
){....}-{4:4}
, at: device_lock include/linux/device.h:884 [inline]
, at: hub_event+0x1be/0x5060 drivers/usb/core/hub.c:5898
#3:
ffff888111ab2198
(
&dev->mutex){....}-{4:4}, at: device_lock include/linux/device.h:884 [inline]
&dev->mutex){....}-{4:4}, at: usb_disconnect+0x10a/0x9c0 drivers/usb/core/hub.c:2335
#4:
ffff888111ab0160
(
&dev->mutex){....}-{4:4}, at: device_lock include/linux/device.h:884 [inline]
&dev->mutex){....}-{4:4}, at: __device_driver_lock drivers/base/dd.c:1094 [inline]
&dev->mutex){....}-{4:4}, at: device_release_driver_internal+0xa4/0x620 drivers/base/dd.c:1292
#5:
ffffffff89e0dd28 (
input_mutex
){+.+.}-{4:4}
, at: class_mutex_constructor include/linux/mutex.h:225 [inline]
, at: __input_unregister_device+0x156/0x470 drivers/input/input.c:2221
2 locks held by kworker/u8:1/8008:
#0:
ffff888100089148 ((wq_completion)events_unbound){+.+.}-{0:0}, at: process_one_work+0x12a2/0x1b70 kernel/workqueue.c:3213
#1:
ffffc900017cfd10
(
(work_completion)(&sub_info->work)){+.+.}-{0:0}
, at: process_one_work+0x929/0x1b70 kernel/workqueue.c:3214
2 locks held by kworker/u8:4/8016:
#0:
ffff888100089148 (
(wq_completion)events_unbound
){+.+.}-{0:0}, at: process_one_work+0x12a2/0x1b70 kernel/workqueue.c:3213
#1:
ffffc90013bdfd10 ((work_completion)(&sub_info->work)
){+.+.}-{0:0}
, at: process_one_work+0x929/0x1b70 kernel/workqueue.c:3214
2 locks held by kworker/u8:6/8018:
#0:
ffff888100089148
((wq_completion)events_unbound
){+.+.}-{0:0}
, at: process_one_work+0x12a2/0x1b70 kernel/workqueue.c:3213
#1:
ffffc90013bbfd10
(
(work_completion)(&sub_info->work)){+.+.}-{0:0}
, at: process_one_work+0x929/0x1b70 kernel/workqueue.c:3214
1 lock held by modprobe/8085:
#0:
ffff8881f5938858
(&rq->__lock
){-.-.}-{2:2}
, at: raw_spin_rq_lock_nested kernel/sched/core.c:606 [inline]
, at: raw_spin_rq_lock kernel/sched/sched.h:1532 [inline]
, at: rq_lock kernel/sched/sched.h:1856 [inline]
, at: __schedule+0x2f0/0x3b10 kernel/sched/core.c:6710
1 lock held by modprobe/8094:
=============================================
NMI backtrace for cpu 0
CPU: 0 UID: 0 PID: 30 Comm: khungtaskd Not tainted 6.16.0-rc7-syzkaller-g51d4b0a44c82 #0 PREEMPT(voluntary)
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 07/12/2025
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:158 [inline]
check_hung_uninterruptible_tasks kernel/hung_task.c:307 [inline]
watchdog+0xf70/0x12c0 kernel/hung_task.c:470
kthread+0x3c2/0x780 kernel/kthread.c:464
ret_from_fork+0x5b3/0x6c0 arch/x86/kernel/process.c:148
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: 37 Comm: kworker/1:1 Not tainted 6.16.0-rc7-syzkaller-g51d4b0a44c82 #0 PREEMPT(voluntary)
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 07/12/2025
Workqueue: events dvb_usb_read_remote_control
RIP: 0010:io_serial_in+0x87/0xb0 drivers/tty/serial/8250/8250_port.c:410
Code: 1d a8 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 8d 86 5c 04 e8 08 1e 05 ff eb a2 e8 91 1e
RSP: 0018:ffffc90000277720 EFLAGS: 00000002
RAX: dffffc0000000000 RBX: 00000000000003fd RCX: 0000000000000000
RDX: 00000000000003fd RSI: ffffffff82d57920 RDI: ffffffff9392af80
RBP: ffffffff9392af40 R08: 0000000000000001 R09: 000000000000001f
R10: 0000000000000000 R11: 0000000000000001 R12: 0000000000000000
R13: 0000000000000020 R14: fffffbfff2725642 R15: dffffc0000000000
FS: 0000000000000000(0000) GS:ffff888269260000(0000) knlGS:0000000000000000
CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 00007fe0c4167e9c CR3: 0000000008ea4000 CR4: 00000000003506f0
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+0x13a/0x210 drivers/tty/serial/8250/8250_port.c:2094
fifo_wait_for_lsr drivers/tty/serial/8250/8250_port.c:3348 [inline]
serial8250_console_fifo_write drivers/tty/serial/8250/8250_port.c:3371 [inline]
serial8250_console_write+0xf83/0x1890 drivers/tty/serial/8250/8250_port.c:3456
console_emit_next_record kernel/printk/printk.c:3138 [inline]
console_flush_all+0x801/0xc60 kernel/printk/printk.c:3226
__console_flush_and_unlock kernel/printk/printk.c:3285 [inline]
console_unlock+0xd8/0x210 kernel/printk/printk.c:3325
vprintk_emit+0x418/0x6d0 kernel/printk/printk.c:2450
_printk+0xc7/0x100 kernel/printk/printk.c:2475
m920x_read drivers/media/usb/dvb-usb/m920x.c:40 [inline]
m920x_rc_core_query+0x2d7/0x500 drivers/media/usb/dvb-usb/m920x.c:229
dvb_usb_read_remote_control+0xda/0x1c0 drivers/media/usb/dvb-usb/dvb-usb-remote.c:261
process_one_work+0x9cc/0x1b70 kernel/workqueue.c:3238
process_scheduled_works kernel/workqueue.c:3321 [inline]
worker_thread+0x6c8/0xf10 kernel/workqueue.c:3402
kthread+0x3c2/0x780 kernel/kthread.c:464
ret_from_fork+0x5b3/0x6c0 arch/x86/kernel/process.c:148
ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:245