INFO: task udevd:8555 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:26488 pid:8555 tgid:8555 ppid:2841 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: 0033:0x7fa7e2fd8b6a
RSP: 002b:00007ffefd4552e8 EFLAGS: 00000246
ORIG_RAX: 0000000000000000
RAX: ffffffffffffffda RBX: 000055f2a18ecda0 RCX: 00007fa7e2fd8b6a
RDX: 0000000000001000 RSI: 000055f2a18cac00 RDI: 0000000000000008
RBP: 000055f2a18ecda0 R08: 0000000000000008 R09: 0000000000000004
R10: 000000000000010f R11: 0000000000000246 R12: 0000000000000000
R13: 0000000000003fff R14: 00007ffefd4557c8 R15: 000000000000000a
INFO: task udevd:8555 is blocked on a mutex likely owned by task kworker/1:2:1114.
task:kworker/1:2 state:R
running task stack:21080 pid:1114 tgid:1114 ppid:2 task_flags:0x4208060 flags:0x00004000
Workqueue: usb_hub_wq hub_event
Call Trace:
context_switch kernel/sched/core.c:5382 [inline]
__schedule+0x132a/0x3b00 kernel/sched/core.c:6767
lockdep_hardirqs_on+0x7c/0x110 kernel/locking/lockdep.c:4473
Showing all locks held in the system:
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
11 locks held by kworker/1:2/1114:
2 locks held by getty/2901:
#0: ffff88811213f0a0 (&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
5 locks held by kworker/0:3/5232:
4 locks held by kworker/1:5/5327:
#0:
ffff8881f5938418 (&rq->__lock){-.-.}-{2:2}
, at: process_one_work+0x12a2/0x1b70 kernel/workqueue.c:3213
#1: ffffc900023cfd18 ((work_completion)(&(&d->rc_query_work)->work)#2){+.+.}-{0:0}, at: process_one_work+0x929/0x1b70 kernel/workqueue.c:3214
#2: ffff8881f5938418 (&rq->__lock){-.-.}-{2:2}
, at: lock_timer_base+0x127/0x1d0 kernel/time/timer.c:1046
#3: ffffffff937fbab0 (&obj_hash[i].lock
){-.-.}-{2:2}, at: debug_object_activate+0x14c/0x4c0 lib/debugobjects.c:818
4 locks held by udevd/8555:
#0:
ffff88811bf2f2f0 (&p->lock){+.+.}-{4:4}, at: seq_read_iter+0xe1/0x12b0 fs/seq_file.c:182
#1: ffff88811d802888 (&of->mutex#2){+.+.}-{4:4}, at: kernfs_seq_start+0x4d/0x240 fs/kernfs/file.c:154
#2: ffff8881183d4c38 (kn->active#5){++++}-{0:0}
, at: kernfs_seq_start+0x71/0x240 fs/kernfs/file.c:155
#3:
ffff888114c07198 (&dev->mutex){....}-{4:4}
, at: device_lock include/linux/device.h:922 [inline]
, at: uevent_show+0x187/0x3b0 drivers/base/core.c:2730
4 locks held by udevd/8562:
#0:
ffff88812a313790 (&p->lock){+.+.}-{4:4}, at: seq_read_iter+0xe1/0x12b0 fs/seq_file.c:182
#1: ffff88812dae3888 (&of->mutex
#2){+.+.}-{4:4}, at: kernfs_seq_start+0x4d/0x240 fs/kernfs/file.c:154
#2: ffff88811e1ec0f8 (
kn->active#5){++++}-{0:0}, at: kernfs_seq_start+0x71/0x240 fs/kernfs/file.c:155
#3: ffff88811e960198 (
&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
4 locks held by udevd/8608:
#0: ffff88810931b8b8 (&p->lock){+.+.}-{4:4}, at: seq_read_iter+0xe1/0x12b0 fs/seq_file.c:182
#1: ffff88810fbc4888 (
&of->mutex#2){+.+.}-{4:4}, at: kernfs_seq_start+0x4d/0x240 fs/kernfs/file.c:154
#2:
ffff88811c1ecd28 (kn->active
#5){++++}-{0:0}
, at: kernfs_seq_start+0x71/0x240 fs/kernfs/file.c:155
#3: ffff888131655160 (&dev->mutex){....}-{4:4}
, at: device_lock include/linux/device.h:922 [inline]
, at: uevent_show+0x187/0x3b0 drivers/base/core.c:2730
3 locks held by kworker/1:7/8993:
3 locks held by kworker/0:4/10630:
6 locks held by kworker/1:8/12872:
#0: ffff888106ee5148 ((wq_completion)usb_hub_wq
){+.+.}-{0:0}, at: process_one_work+0x12a2/0x1b70 kernel/workqueue.c:3213
#1: ffffc90006847d18 ((work_completion)(&hub->events)
){+.+.}-{0:0}, at: process_one_work+0x929/0x1b70 kernel/workqueue.c:3214
#2: ffff88810b7b9198 (&dev->mutex){....}-{4:4}
, at: device_lock include/linux/device.h:922 [inline]
, at: hub_event+0x1be/0x5030 drivers/usb/core/hub.c:5863
#3:
ffff8881189ff198 (&dev->mutex
){....}-{4:4}, at: device_lock include/linux/device.h:922 [inline]
){....}-{4:4}, at: __device_attach+0x7e/0x4b0 drivers/base/dd.c:1005
#4: ffff888131655160 (&dev->mutex){....}-{4:4}, at: device_lock include/linux/device.h:922 [inline]
#4: ffff888131655160 (&dev->mutex){....}-{4:4}, at: __device_attach+0x7e/0x4b0 drivers/base/dd.c:1005
#5: ffff88810fea4668 (hcd->bandwidth_mutex){+.+.}-{4:4}
, at: usb_set_interface+0x299/0xed0 drivers/usb/core/message.c:1564
6 locks held by kworker/0:8/13903:
1 lock held by syz.9.2958/17606:
3 locks held by syz.7.2959/17609:
=============================================
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: 14058 Comm: kworker/1:10 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:__min_vruntime_update kernel/sched/fair.c:809 [inline]
RIP: 0010:min_vruntime_update kernel/sched/fair.c:834 [inline]
RIP: 0010:min_vruntime_cb_propagate kernel/sched/fair.c:844 [inline]
RIP: 0010:rb_add_augmented_cached include/linux/rbtree_augmented.h:83 [inline]
RIP: 0010:__enqueue_entity+0x38b/0xb70 kernel/sched/fair.c:855
Code: 2a 00 0f 85 ae 04 00 00 49 8b 7d 20 4d 89 e2 49 29 fa 4d 85 d2 4c 0f 4f e7 4c 89 63 20 4d 85 f6 0f 84 54 01 00 00 49 8d 7e 20 <49> 89 fa 49 c1 ea 03 41 80 3c 2a 00 0f 85 e6 04 00 00 49 8b 7e 20
RSP: 0018:ffffc900001a8c10 EFLAGS: 00000082
RAX: 000000924e5050cf RBX: ffff888114869dd0 RCX: ffff88811276b810
RDX: ffff8881f59384c0 RSI: ffff8881f59384f8 RDI: ffff888116653b30
RBP: dffffc0000000000 R08: 0000000000000001 R09: 0000000000155cc0
R10: ffffffffff64293d R11: 0000000000000000 R12: 000000924eba6318
R13: ffff88810f399dd0 R14: ffff888116653b10 R15: 0000000000155cc0
FS: 0000000000000000(0000) GS:ffff8882692d3000(0000) knlGS:0000000000000000
CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 0000001b2e320220 CR3: 0000000127062000 CR4: 00000000003506f0
DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400
Call Trace:
enqueue_entity kernel/sched/fair.c:5362 [inline]
enqueue_task_fair+0x3d4/0x2100 kernel/sched/fair.c:6980
enqueue_task+0x6d/0x200 kernel/sched/core.c:2075
activate_task kernel/sched/core.c:2122 [inline]
ttwu_do_activate+0x135/0x8f0 kernel/sched/core.c:3732
ttwu_queue kernel/sched/core.c:4000 [inline]
try_to_wake_up+0x709/0x13f0 kernel/sched/core.c:4328
hrtimer_wakeup+0x47/0x60 kernel/time/hrtimer.c:1997
__run_hrtimer kernel/time/hrtimer.c:1761 [inline]
__hrtimer_run_queues+0x1ff/0xad0 kernel/time/hrtimer.c:1825
hrtimer_interrupt+0x397/0x8e0 kernel/time/hrtimer.c:1887
local_apic_timer_interrupt arch/x86/kernel/apic/apic.c:1038 [inline]
__sysvec_apic_timer_interrupt+0x108/0x3f0 arch/x86/kernel/apic/apic.c:1055
instr_sysvec_apic_timer_interrupt arch/x86/kernel/apic/apic.c:1049 [inline]
sysvec_apic_timer_interrupt+0x8b/0xb0 arch/x86/kernel/apic/apic.c:1049
asm_sysvec_apic_timer_interrupt+0x1a/0x20 arch/x86/include/asm/idtentry.h:702
RIP: 0010:console_trylock_spinning kernel/printk/printk.c:2061 [inline]
RIP: 0010:vprintk_emit+0x567/0x6d0 kernel/printk/printk.c:2449
Code: 00 4d 85 ed 0f 85 19 01 00 00 e8 74 dd 1f 00 9c 5d 81 e5 00 02 00 00 31 ff 48 89 ee e8 d2 d8 1f 00 48 85 ed 0f 85 25 01 00 00 54 dd 1f 00 45 31 c9 41 b8 01 00 00 00 31 c9 48 8d 05 00 00 00
RSP: 0018:ffffc90001e9f9f0 EFLAGS: 00000293
RAX: 0000000000000000 RBX: 0000000000000017 RCX: ffffffff815c6d1c
RDX: ffff888104ed1d40 RSI: ffffffff815c6d26 RDI: 0000000000000007
RBP: 0000000000000000 R08: 0000000000000007 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000000 R12: 1ffff920003d3f40
R13: 0000000000000200 R14: ffff8881022857c0 R15: ffffc90001e9fab8
_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