INFO: task udevd:5241 blocked for more than 143 seconds.
Not tainted 6.15.0-rc1-syzkaller-00098-ge94b19bf8e91 #0
"echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message.
task:udevd state:D stack:24536 pid:5241 tgid:5241 ppid:2839 task_flags:0x400140 flags:0x00000002
Call Trace:
context_switch kernel/sched/core.c:5382 [inline]
__schedule+0x132a/0x3b00 kernel/sched/core.c:6767
__schedule_loop kernel/sched/core.c:6845 [inline]
schedule+0xe7/0x3a0 kernel/sched/core.c:6860
schedule_preempt_disabled+0x13/0x30 kernel/sched/core.c:6917
__mutex_lock_common kernel/locking/mutex.c:678 [inline]
__mutex_lock+0x6c7/0xb90 kernel/locking/mutex.c:746
device_lock include/linux/device.h:922 [inline]
uevent_show+0x187/0x3b0 drivers/base/core.c:2730
dev_attr_show+0x53/0xe0 drivers/base/core.c:2424
sysfs_kf_seq_show+0x213/0x3e0 fs/sysfs/file.c:65
seq_read_iter+0x506/0x12b0 fs/seq_file.c:230
kernfs_fop_read_iter+0x422/0x5a0 fs/kernfs/file.c:279
new_sync_read fs/read_write.c:489 [inline]
vfs_read+0x8c8/0xc70 fs/read_write.c:570
ksys_read+0x12a/0x240 fs/read_write.c:713
do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline]
do_syscall_64+0xcd/0x260 arch/x86/entry/syscall_64.c:94
entry_SYSCALL_64_after_hwframe+0x77/0x7f
RIP: 0033:0x7f6affdc1b6a
RSP: 002b:00007ffe6e942068 EFLAGS: 00000246 ORIG_RAX: 0000000000000000
RAX: ffffffffffffffda RBX: 00005578b155e880 RCX: 00007f6affdc1b6a
RDX: 0000000000001000 RSI: 00005578b1584d00 RDI: 0000000000000001
RBP: 00005578b155e880 R08: 0000000000000001 R09: 0000000000000010
R10: 000000000000010f R11: 0000000000000246 R12: 0000000000000000
R13: 0000000000003fff R14: 00007ffe6e942548 R15: 000000000000000a
INFO: task udevd:5241 is blocked on a mutex likely owned by task kworker/1:8:19485.
task:kworker/1:8 state:R
running task stack:22312 pid:19485 tgid:19485 ppid:2 task_flags:0x4208060 flags:0x00004008
Workqueue: usb_hub_wq hub_event
Call Trace:
context_switch kernel/sched/core.c:5382 [inline]
__schedule+0x132a/0x3b00 kernel/sched/core.c:6767
preempt_schedule_common+0x44/0xc0 kernel/sched/core.c:6947
__cond_resched+0x22/0x30 kernel/sched/core.c:7292
might_resched include/linux/kernel.h:73 [inline]
__pm_runtime_resume+0x137/0x170 drivers/base/power/runtime.c:1173
__pm_runtime_idle+0xcc/0x1a0 drivers/base/power/runtime.c:1115
usbnet_read_cmd+0xbe/0x100 drivers/net/usb/usbnet.c:2102
Showing all locks held in the system:
3 locks held by kworker/0:0/9:
1 lock held by khungtaskd/30:
#0: ffffffff890c1a00
(
rcu_read_lock){....}-{1:3}, at: rcu_lock_acquire include/linux/rcupdate.h:331 [inline]
rcu_read_lock){....}-{1:3}, at: rcu_read_lock include/linux/rcupdate.h:841 [inline]
rcu_read_lock){....}-{1:3}, at: debug_show_all_locks+0x36/0x1c0 kernel/locking/lockdep.c:6764
2 locks held by getty/2899:
#0:
ffff8881126520a0 (&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
3 locks held by kworker/1:3/5201:
#0: ffff8881066af148 ((wq_completion)usb_hub_wq){+.+.}-{0:0}, at: process_one_work+0x12a2/0x1b70 kernel/workqueue.c:3213
#1:
ffffc90001fffd18
((work_completion)(&hub->events)
){+.+.}-{0:0}, at: process_one_work+0x929/0x1b70 kernel/workqueue.c:3214
#2: ffff88810b741198 (&dev->mutex){....}-{4:4}
, at: device_lock include/linux/device.h:922 [inline]
, at: hub_event+0x1be/0x5030 drivers/usb/core/hub.c:5863
4 locks held by udevd/5241:
#0: ffff8881237a19e0 (
&p->lock
){+.+.}-{4:4}, at: seq_read_iter+0xe1/0x12b0 fs/seq_file.c:182
#1: ffff88811a75b488 (
&of->mutex
#2){+.+.}-{4:4}, at: kernfs_seq_start+0x4d/0x240 fs/kernfs/file.c:154
#2: ffff88810a77b698 (kn->active
#5
){++++}-{0:0}
, at: kernfs_seq_start+0x71/0x240 fs/kernfs/file.c:155
#3: ffff88810b399198 (
&dev->mutex){....}-{4:4}, at: device_lock include/linux/device.h:922 [inline]
&dev->mutex){....}-{4:4}, at: uevent_show+0x187/0x3b0 drivers/base/core.c:2730
11 locks held by kworker/1:8/19485:
5 locks held by kworker/0:8/24578:
=============================================
NMI backtrace for cpu 0
CPU: 0 UID: 0 PID: 30 Comm: khungtaskd Not tainted 6.15.0-rc1-syzkaller-00098-ge94b19bf8e91 #0 PREEMPT(voluntary)
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 02/12/2025
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:274 [inline]
watchdog+0x11c4/0x15d0 kernel/hung_task.c:437
kthread+0x3c2/0x780 kernel/kthread.c:464
ret_from_fork+0x45/0x80 arch/x86/kernel/process.c:153
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: 5201 Comm: kworker/1:3 Not tainted 6.15.0-rc1-syzkaller-00098-ge94b19bf8e91 #0 PREEMPT(voluntary)
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 02/12/2025
Workqueue: events legacy_dvb_usb_read_remote_control
RIP: 0010:vsnprintf+0xa28/0x1160 lib/vsprintf.c:2839
Code: 5c fa 41 83 fd 2f 0f 87 17 02 00 00 e8 31 31 5c fa 49 8d 7f 10 48 ba 00 00 00 00 00 fc ff df 48 89 f9 48 c1 e9 03 80 3c 11 00 <0f> 85 aa 06 00 00 48 8b 74 24 48 41 8d 45 08 45 89 ef 89 06 4c 03
RSP: 0018:ffffc90001fff300 EFLAGS: 00000246
RAX: 0000000000000000 RBX: ffffffff8748ff02 RCX: 1ffff920003ffe83
RDX: dffffc0000000000 RSI: ffffffff8720182f RDI: ffffc90001fff418
RBP: ffffc90001fff3d8 R08: 0000000000000005 R09: 000000000000002f
R10: 0000000000000018 R11: 00000000010983b0 R12: 0000000000000404
R13: 0000000000000018 R14: 0000000000000404 R15: ffffc90001fff408
FS: 0000000000000000(0000) GS:ffff8882692d3000(0000) knlGS:0000000000000000
CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 000055555ae014a8 CR3: 0000000133464000 CR4: 00000000003506f0
DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400
Call Trace:
snprintf+0xc7/0x100 lib/vsprintf.c:2946
print_caller kernel/printk/printk.c:1390 [inline]
info_print_prefix+0x134/0x350 kernel/printk/printk.c:1409
record_print_text+0x140/0x400 kernel/printk/printk.c:1456
printk_get_next_message+0x2d1/0x6d0 kernel/printk/printk.c:3024
console_emit_next_record kernel/printk/printk.c:3092 [inline]
console_flush_all+0x6ea/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_query+0x496/0x770 drivers/media/usb/dvb-usb/m920x.c:193
legacy_dvb_usb_read_remote_control+0x109/0x4f0 drivers/media/usb/dvb-usb/dvb-usb-remote.c:123
process_one_work+0x9cc/0x1b70 kernel/workqueue.c:3238
process_scheduled_works kernel/workqueue.c:3319 [inline]
worker_thread+0x6c8/0xf10 kernel/workqueue.c:3400
kthread+0x3c2/0x780 kernel/kthread.c:464
ret_from_fork+0x45/0x80 arch/x86/kernel/process.c:153
ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:245