[syzbot] [usb?] [kernfs?] INFO: task hung in kernfs_remove_by_name_ns (2)

[syzbot]

Hello,

syzbot found the following issue on:

HEAD commit: d2f51b3516da Merge tag 'rtc-6.7' of git://git.kernel.org/p..
git tree: https://git.kernel.org/pub/scm/linux/kernel/git/gregkh/usb.git usb-testing
console output: https://syzkaller.appspot.com/x/log.txt?x=10e2e3cf680000
kernel config: https://syzkaller.appspot.com/x/.config?x=2021722a434c0122
dashboard link: https://syzkaller.appspot.com/bug?extid=6d5664213a6db9a5a72c
compiler: gcc (Debian 12.2.0-14) 12.2.0, GNU ld (GNU Binutils for Debian) 2.40
syz repro: https://syzkaller.appspot.com/x/repro.syz?x=154bc7b0e80000
C reproducer: https://syzkaller.appspot.com/x/repro.c?x=13febd7b680000

Downloadable assets:
disk image: https://storage.googleapis.com/syzbot-assets/44b35e47f449/disk-d2f51b35.raw.xz
vmlinux: https://storage.googleapis.com/syzbot-assets/f3024be63176/vmlinux-d2f51b35.xz
kernel image: https://storage.googleapis.com/syzbot-assets/795a9fa6dcf3/bzImage-d2f51b35.xz

IMPORTANT: if you fix the issue, please add the following tag to the commit:
Reported-by: syzbot+6d5664...@syzkaller.appspotmail.com

INFO: task kworker/0:2:1113 blocked for more than 143 seconds.
Not tainted 6.6.0-syzkaller-14651-gd2f51b3516da #0
"echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message.
task:kworker/0:2 state:D
stack:24880 pid:1113 tgid:1113 ppid:2 flags:0x00004000
Workqueue: usb_hub_wq hub_event

Call Trace:
<TASK>
context_switch kernel/sched/core.c:5376 [inline]
__schedule+0xc71/0x3050 kernel/sched/core.c:6688
__schedule_loop kernel/sched/core.c:6763 [inline]
schedule+0xe7/0x270 kernel/sched/core.c:6778
schedule_preempt_disabled+0x13/0x20 kernel/sched/core.c:6835
rwsem_down_write_slowpath+0x53d/0x12a0 kernel/locking/rwsem.c:1178
__down_write_common kernel/locking/rwsem.c:1306 [inline]
__down_write kernel/locking/rwsem.c:1315 [inline]
down_write+0x1d3/0x200 kernel/locking/rwsem.c:1580
kernfs_remove_by_name_ns+0x87/0x120 fs/kernfs/dir.c:1668
device_remove_sys_dev_entry drivers/base/core.c:3464 [inline]
device_del+0x84e/0xa50 drivers/base/core.c:3794
device_unregister+0x1d/0xc0 drivers/base/core.c:3855
device_destroy+0x9a/0xd0 drivers/base/core.c:4414
usb_deregister_dev+0x70/0x1e0 drivers/usb/core/file.c:184
imon_disconnect+0x57f/0x660 drivers/media/rc/imon.c:2527
usb_unbind_interface+0x1dd/0x8d0 drivers/usb/core/driver.c:458
device_remove drivers/base/dd.c:569 [inline]
device_remove+0x11f/0x170 drivers/base/dd.c:561
__device_release_driver drivers/base/dd.c:1272 [inline]
device_release_driver_internal+0x44a/0x610 drivers/base/dd.c:1295
bus_remove_device+0x22c/0x420 drivers/base/bus.c:574
device_del+0x39a/0xa50 drivers/base/core.c:3814
usb_disable_device+0x36c/0x7f0 drivers/usb/core/message.c:1416
usb_disconnect+0x2e1/0x910 drivers/usb/core/hub.c:2260
hub_port_connect drivers/usb/core/hub.c:5303 [inline]
hub_port_connect_change drivers/usb/core/hub.c:5603 [inline]
port_event drivers/usb/core/hub.c:5763 [inline]
hub_event+0x1be0/0x4f40 drivers/usb/core/hub.c:5845
process_one_work+0x884/0x15c0 kernel/workqueue.c:2630
process_scheduled_works kernel/workqueue.c:2703 [inline]
worker_thread+0x8b9/0x1290 kernel/workqueue.c:2784
kthread+0x33c/0x440 kernel/kthread.c:388
ret_from_fork+0x45/0x80 arch/x86/kernel/process.c:147
ret_from_fork_asm+0x11/0x20 arch/x86/entry/entry_64.S:242
</TASK>
INFO: task udevd:2397 blocked for more than 144 seconds.
Not tainted 6.6.0-syzkaller-14651-gd2f51b3516da #0
"echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message.
task:udevd state:D
stack:26672 pid:2397 tgid:2397 ppid:1 flags:0x00000002
Call Trace:
<TASK>
context_switch kernel/sched/core.c:5376 [inline]
__schedule+0xc71/0x3050 kernel/sched/core.c:6688
__schedule_loop kernel/sched/core.c:6763 [inline]
schedule+0xe7/0x270 kernel/sched/core.c:6778
schedule_preempt_disabled+0x13/0x20 kernel/sched/core.c:6835
rwsem_down_read_slowpath+0x61e/0xb20 kernel/locking/rwsem.c:1086
__down_read_common kernel/locking/rwsem.c:1250 [inline]
__down_read kernel/locking/rwsem.c:1263 [inline]
down_read+0xf0/0x470 kernel/locking/rwsem.c:1528
kernfs_dop_revalidate+0xf0/0x5a0 fs/kernfs/dir.c:1138
d_revalidate fs/namei.c:862 [inline]
d_revalidate fs/namei.c:859 [inline]
lookup_fast+0x232/0x520 fs/namei.c:1655
walk_component+0x5b/0x5a0 fs/namei.c:1998
link_path_walk.part.0.constprop.0+0x71f/0xce0 fs/namei.c:2329
link_path_walk fs/namei.c:2254 [inline]
path_openat+0x240/0x2c40 fs/namei.c:3775
do_filp_open+0x1de/0x430 fs/namei.c:3809
do_sys_openat2+0x176/0x1e0 fs/open.c:1440
do_sys_open fs/open.c:1455 [inline]
__do_sys_openat fs/open.c:1471 [inline]
__se_sys_openat fs/open.c:1466 [inline]
__x64_sys_openat+0x175/0x210 fs/open.c:1466
do_syscall_x64 arch/x86/entry/common.c:51 [inline]
do_syscall_64+0x3f/0x110 arch/x86/entry/common.c:82
entry_SYSCALL_64_after_hwframe+0x63/0x6b
RIP: 0033:0x7f5eaee1b9a4
RSP: 002b:00007ffec94fca10 EFLAGS: 00000246
ORIG_RAX: 0000000000000101
RAX: ffffffffffffffda RBX: 0000000000000008 RCX: 00007f5eaee1b9a4
RDX: 0000000000080000 RSI: 00007ffec94fcb48 RDI: 00000000ffffff9c
RBP: 00007ffec94fcb48 R08: 0000000000000008 R09: 0000000000000001
R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000080000
R13: 000055f152075b42 R14: 0000000000000001 R15: 0000000000000000
</TASK>
INFO: task udevd:2519 blocked for more than 145 seconds.
Not tainted 6.6.0-syzkaller-14651-gd2f51b3516da #0
"echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message.
task:udevd state:D
stack:27936 pid:2519 tgid:2519 ppid:2397 flags:0x00004002
Call Trace:
<TASK>
context_switch kernel/sched/core.c:5376 [inline]
__schedule+0xc71/0x3050 kernel/sched/core.c:6688
__schedule_loop kernel/sched/core.c:6763 [inline]
schedule+0xe7/0x270 kernel/sched/core.c:6778
schedule_preempt_disabled+0x13/0x20 kernel/sched/core.c:6835
rwsem_down_read_slowpath+0x61e/0xb20 kernel/locking/rwsem.c:1086
__down_read_common kernel/locking/rwsem.c:1250 [inline]
__down_read kernel/locking/rwsem.c:1263 [inline]
down_read+0xf0/0x470 kernel/locking/rwsem.c:1528
kernfs_dop_revalidate+0xf0/0x5a0 fs/kernfs/dir.c:1138
d_revalidate fs/namei.c:862 [inline]
d_revalidate fs/namei.c:859 [inline]
lookup_fast+0x232/0x520 fs/namei.c:1655
walk_component+0x5b/0x5a0 fs/namei.c:1998
link_path_walk.part.0.constprop.0+0x71f/0xce0 fs/namei.c:2329
link_path_walk fs/namei.c:2254 [inline]
path_openat+0x240/0x2c40 fs/namei.c:3775
do_filp_open+0x1de/0x430 fs/namei.c:3809
do_sys_openat2+0x176/0x1e0 fs/open.c:1440
do_sys_open fs/open.c:1455 [inline]
__do_sys_openat fs/open.c:1471 [inline]
__se_sys_openat fs/open.c:1466 [inline]
__x64_sys_openat+0x175/0x210 fs/open.c:1466
do_syscall_x64 arch/x86/entry/common.c:51 [inline]
do_syscall_64+0x3f/0x110 arch/x86/entry/common.c:82
entry_SYSCALL_64_after_hwframe+0x63/0x6b
RIP: 0033:0x7f5eaee1b9a4
RSP: 002b:00007ffec94fc860 EFLAGS: 00000246
ORIG_RAX: 0000000000000101
RAX: ffffffffffffffda RBX: 0000000000000008 RCX: 00007f5eaee1b9a4
RDX: 0000000000080000 RSI: 00007ffec94fc998 RDI: 00000000ffffff9c
RBP: 00007ffec94fc998 R08: 0000000000000008 R09: 0000000000000001
R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000080000
R13: 000055f152075b42 R14: 0000000000000001 R15: 000055f153a28910
</TASK>
INFO: task udevd:2526 blocked for more than 146 seconds.
Not tainted 6.6.0-syzkaller-14651-gd2f51b3516da #0
"echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message.
task:udevd state:D
stack:27376 pid:2526 tgid:2526 ppid:2397 flags:0x00004002
Call Trace:
<TASK>
context_switch kernel/sched/core.c:5376 [inline]
__schedule+0xc71/0x3050 kernel/sched/core.c:6688
__schedule_loop kernel/sched/core.c:6763 [inline]
schedule+0xe7/0x270 kernel/sched/core.c:6778
schedule_preempt_disabled+0x13/0x20 kernel/sched/core.c:6835
rwsem_down_read_slowpath+0x61e/0xb20 kernel/locking/rwsem.c:1086
__down_read_common kernel/locking/rwsem.c:1250 [inline]
__down_read kernel/locking/rwsem.c:1263 [inline]
down_read+0xf0/0x470 kernel/locking/rwsem.c:1528
kernfs_dop_revalidate+0xf0/0x5a0 fs/kernfs/dir.c:1138
d_revalidate fs/namei.c:862 [inline]
d_revalidate fs/namei.c:859 [inline]
lookup_fast+0x232/0x520 fs/namei.c:1655
walk_component+0x5b/0x5a0 fs/namei.c:1998
link_path_walk.part.0.constprop.0+0x71f/0xce0 fs/namei.c:2329
link_path_walk fs/namei.c:2253 [inline]
path_lookupat+0x93/0x770 fs/namei.c:2482
filename_lookup+0x1e7/0x5b0 fs/namei.c:2512
user_path_at_empty+0x42/0x60 fs/namei.c:2911
do_readlinkat+0xdd/0x310 fs/stat.c:490
__do_sys_readlink fs/stat.c:523 [inline]
__se_sys_readlink fs/stat.c:520 [inline]
__x64_sys_readlink+0x78/0xb0 fs/stat.c:520
do_syscall_x64 arch/x86/entry/common.c:51 [inline]
do_syscall_64+0x3f/0x110 arch/x86/entry/common.c:82
entry_SYSCALL_64_after_hwframe+0x63/0x6b
RIP: 0033:0x7f5eaee1cd47
RSP: 002b:00007ffec94fba88 EFLAGS: 00000202
ORIG_RAX: 0000000000000059
RAX: ffffffffffffffda RBX: 000055f153a3efd0 RCX: 00007f5eaee1cd47
RDX: 0000000000000400 RSI: 00007ffec94fbe98 RDI: 00007ffec94fba98
RBP: 00007ffec94fc2d8 R08: 000055f15207c1fd R09: 0000000000000000
R10: 0000000000000010 R11: 0000000000000202 R12: 0000000000000200
R13: 00007ffec94fbe98 R14: 00007ffec94fba98 R15: 000055f152076a04
</TASK>
INFO: task udevd:2536 blocked for more than 146 seconds.
Not tainted 6.6.0-syzkaller-14651-gd2f51b3516da #0
"echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message.
task:udevd state:D
stack:28144 pid:2536 tgid:2536 ppid:2397 flags:0x00000002
Call Trace:
<TASK>
context_switch kernel/sched/core.c:5376 [inline]
__schedule+0xc71/0x3050 kernel/sched/core.c:6688
__schedule_loop kernel/sched/core.c:6763 [inline]
schedule+0xe7/0x270 kernel/sched/core.c:6778
schedule_preempt_disabled+0x13/0x20 kernel/sched/core.c:6835
rwsem_down_read_slowpath+0x61e/0xb20 kernel/locking/rwsem.c:1086
__down_read_common kernel/locking/rwsem.c:1250 [inline]
__down_read kernel/locking/rwsem.c:1263 [inline]
down_read+0xf0/0x470 kernel/locking/rwsem.c:1528
kernfs_dop_revalidate+0xf0/0x5a0 fs/kernfs/dir.c:1138
d_revalidate fs/namei.c:862 [inline]
d_revalidate fs/namei.c:859 [inline]
lookup_fast+0x232/0x520 fs/namei.c:1655
walk_component+0x5b/0x5a0 fs/namei.c:1998
link_path_walk.part.0.constprop.0+0x71f/0xce0 fs/namei.c:2329
link_path_walk fs/namei.c:2254 [inline]
path_openat+0x240/0x2c40 fs/namei.c:3775
do_filp_open+0x1de/0x430 fs/namei.c:3809
do_sys_openat2+0x176/0x1e0 fs/open.c:1440
do_sys_open fs/open.c:1455 [inline]
__do_sys_openat fs/open.c:1471 [inline]
__se_sys_openat fs/open.c:1466 [inline]
__x64_sys_openat+0x175/0x210 fs/open.c:1466
do_syscall_x64 arch/x86/entry/common.c:51 [inline]
do_syscall_64+0x3f/0x110 arch/x86/entry/common.c:82
entry_SYSCALL_64_after_hwframe+0x63/0x6b
RIP: 0033:0x7f5eaee1b9a4
RSP: 002b:00007ffec94f8420 EFLAGS: 00000246
ORIG_RAX: 0000000000000101
RAX: ffffffffffffffda RBX: 0000000000000008 RCX: 00007f5eaee1b9a4
RDX: 0000000000080000 RSI: 00007ffec94f8558 RDI: 00000000ffffff9c
RBP: 00007ffec94f8558 R08: 0000000000000008 R09: 0000000000000001
R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000080000
R13: 000055f152075b42 R14: 0000000000000001 R15: 000055f152091160
</TASK>

Showing all locks held in the system:
10 locks held by kworker/0:0/8:
6 locks held by kworker/0:1/9:
1 lock held by khungtaskd/29:
#0:
ffffffff87ead2e0
(
rcu_read_lock
){....}-{1:2}
, at: rcu_lock_acquire include/linux/rcupdate.h:301 [inline]
, at: rcu_read_lock include/linux/rcupdate.h:747 [inline]
, at: debug_show_all_locks+0x75/0x340 kernel/locking/lockdep.c:6613
6 locks held by kworker/0:2/1113:
#0:
ffff88810967ed38
((wq_completion)usb_hub_wq){+.+.}-{0:0}
, at: process_one_work+0x787/0x15c0 kernel/workqueue.c:2605
#1:
ffffc9000278fd80
(
(work_completion)(&hub->events)
){+.+.}-{0:0}
, at: process_one_work+0x7e9/0x15c0 kernel/workqueue.c:2606
#2:
ffff888105fc4190
(
&dev->mutex
){....}-{3:3}
, at: device_lock include/linux/device.h:992 [inline]
, at: hub_event+0x1be/0x4f40 drivers/usb/core/hub.c:5791
#3:
ffff888117723190
(
&dev->mutex
){....}-{3:3}
, at: device_lock include/linux/device.h:992 [inline]
, at: usb_disconnect+0x10a/0x910 drivers/usb/core/hub.c:2251
#4:
ffff88810feec160
(
&dev->mutex
){....}-{3:3}
, at: device_lock include/linux/device.h:992 [inline]
, at: __device_driver_lock drivers/base/dd.c:1095 [inline]
, at: device_release_driver_internal+0xa4/0x610 drivers/base/dd.c:1292
#5:
ffff88810165d948
(
&root->kernfs_rwsem
){++++}-{3:3}
, at: kernfs_remove_by_name_ns+0x87/0x120 fs/kernfs/dir.c:1668
1 lock held by udevd/2397:
#0:
ffff88810165d948
(&root->kernfs_rwsem
){++++}-{3:3}
, at: kernfs_dop_revalidate+0xf0/0x5a0 fs/kernfs/dir.c:1138
2 locks held by getty/2455:
#0:
ffff888112eea0a0
(
&tty->ldisc_sem
){++++}-{0:0}
, at: tty_ldisc_ref_wait+0x24/0x80 drivers/tty/tty_ldisc.c:243
#1:
ffffc900000432f0
(
&ldata->atomic_read_lock
){+.+.}-{3:3}
, at: n_tty_read+0xfc6/0x1490 drivers/tty/n_tty.c:2201
4 locks held by udevd/2495:
#0: ffff888107be20a0
(
&p->lock
){+.+.}-{3:3}
, at: seq_read_iter+0xda/0x1280 fs/seq_file.c:182
#1:
ffff888112091488
(
&of->mutex
){+.+.}-{3:3}
, at: kernfs_seq_start+0x4b/0x460 fs/kernfs/file.c:154
#2:
ffff88810bbb4660
(
kn->active#24
){.+.+}-{0:0}
, at: kernfs_seq_start+0x6f/0x460 fs/kernfs/file.c:155
#3: ffff888117723190
(
&dev->mutex
){....}-{3:3}
, at: device_lock_interruptible include/linux/device.h:997 [inline]
, at: manufacturer_show+0x26/0xa0 drivers/usb/core/sysfs.c:142
5 locks held by kworker/0:3/2510:
3 locks held by kworker/0:4/2512:
4 locks held by udevd/2513:
#0:
ffff88810bf0db08
(&p->lock
){+.+.}-{3:3}
, at: seq_read_iter+0xda/0x1280 fs/seq_file.c:182
#1:
ffff88811b1fb888
(
&of->mutex
){+.+.}-{3:3}
, at: kernfs_seq_start+0x4b/0x460 fs/kernfs/file.c:154
#2:
ffff88810c3ce578
(
kn->active#24
){.+.+}-{0:0}
, at: kernfs_seq_start+0x6f/0x460 fs/kernfs/file.c:155
#3:
ffff888117727190
(
&dev->mutex){....}-{3:3}
, at: device_lock_interruptible include/linux/device.h:997 [inline]
, at: manufacturer_show+0x26/0xa0 drivers/usb/core/sysfs.c:142
4 locks held by udevd/2515:
#0: ffff8881022c4418
(
&p->lock
){+.+.}-{3:3}
, at: seq_read_iter+0xda/0x1280 fs/seq_file.c:182
#1:
ffff888107ee1888
(
&of->mutex
){+.+.}-{3:3}
, at: kernfs_seq_start+0x4b/0x460 fs/kernfs/file.c:154
#2:
ffff8881097e4cb8
(
kn->active#24
){.+.+}-{0:0}
, at: kernfs_seq_start+0x6f/0x460 fs/kernfs/file.c:155
#3:
ffff888117724190
(
&dev->mutex
){....}-{3:3}
, at: device_lock_interruptible include/linux/device.h:997 [inline]
, at: manufacturer_show+0x26/0xa0 drivers/usb/core/sysfs.c:142
3 locks held by kworker/0:6/2516:
4 locks held by udevd/2517:
#0: ffff888102287e80
(
&p->lock
){+.+.}-{3:3}
, at: seq_read_iter+0xda/0x1280 fs/seq_file.c:182
#1:
ffff88811b1e2c88
(&of->mutex
){+.+.}-{3:3}
, at: kernfs_seq_start+0x4b/0x460 fs/kernfs/file.c:154
#2:
ffff88810c796da0
(
kn->active
#24
){.+.+}-{0:0}
, at: kernfs_seq_start+0x6f/0x460 fs/kernfs/file.c:155
#3:
ffff888117725190
(
&dev->mutex
){....}-{3:3}
, at: device_lock_interruptible include/linux/device.h:997 [inline]
, at: manufacturer_show+0x26/0xa0 drivers/usb/core/sysfs.c:142
1 lock held by udevd/2519:
#0:
ffff88810165d948
(&root->kernfs_rwsem
){++++}-{3:3}
, at: kernfs_dop_revalidate+0xf0/0x5a0 fs/kernfs/dir.c:1138
1 lock held by udevd/2526:
#0:
ffff88810165d948
(
&root->kernfs_rwsem
){++++}-{3:3}
, at: kernfs_dop_revalidate+0xf0/0x5a0 fs/kernfs/dir.c:1138
1 lock held by udevd/2536:
#0:
ffff88810165d948
(
&root->kernfs_rwsem
){++++}-{3:3}
, at: kernfs_dop_revalidate+0xf0/0x5a0 fs/kernfs/dir.c:1138

=============================================

NMI backtrace for cpu 1
CPU: 1 PID: 29 Comm: khungtaskd Not tainted 6.6.0-syzkaller-14651-gd2f51b3516da #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 10/09/2023
Call Trace:
<TASK>
__dump_stack lib/dump_stack.c:88 [inline]
dump_stack_lvl+0xd9/0x1b0 lib/dump_stack.c:106
nmi_cpu_backtrace+0x277/0x380 lib/nmi_backtrace.c:113
nmi_trigger_cpumask_backtrace+0x26c/0x2d0 lib/nmi_backtrace.c:62
trigger_all_cpu_backtrace include/linux/nmi.h:160 [inline]
check_hung_uninterruptible_tasks kernel/hung_task.c:222 [inline]
watchdog+0xf87/0x1210 kernel/hung_task.c:379
kthread+0x33c/0x440 kernel/kthread.c:388
ret_from_fork+0x45/0x80 arch/x86/kernel/process.c:147
ret_from_fork_asm+0x11/0x20 arch/x86/entry/entry_64.S:242
</TASK>
Sending NMI from CPU 1 to CPUs 0:
imon 4-1:0.0: imon usb_rx_callback_intf0: status(-71): ignored
NMI backtrace for cpu 0
CPU: 0 PID: 2514 Comm: kworker/0:5 Not tainted 6.6.0-syzkaller-14651-gd2f51b3516da #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 10/09/2023
Workqueue: events_power_efficient gc_worker
RIP: 0010:__sanitizer_cov_trace_switch+0x5a/0x90 kernel/kcov.c:342
Code: 4c 8b 75 00 31 db 4d 85 f6 74 1e 48 8b 74 dd 10 4c 89 e2 4c 89 ef 48 83 c3 01 48 8b 4c 24 28 e8 2c fe ff ff 49 39 de 75 e2 5b <5d> 41 5c 41 5d 41 5e c3 48 83 f8 40 41 bd 07 00 00 00 74 c2 5b 5d
RSP: 0018:ffffc90000007068 EFLAGS: 00000046
RAX: 0000000000000000 RBX: ffffffff8688a001 RCX: ffffffff86470150
RDX: ffff88810a3c5700 RSI: 0000000000000007 RDI: 0000000000000001
RBP: ffffffff87502f40 R08: 0000000000000001 R09: 0000000000000007
R10: 0000000000000009 R11: 000000000021a748 R12: 0000000000000009
R13: 0000000000000001 R14: 0000000000000008 R15: 0000000000000009
FS: 0000000000000000(0000) GS:ffff8881f6600000(0000) knlGS:0000000000000000
CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 00007f5eaee2835c CR3: 0000000007c9c000 CR4: 00000000003506f0
DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400
Call Trace:
<NMI>
</NMI>
<IRQ>
vsnprintf+0x160/0x1870 lib/vsprintf.c:2775
sprintf+0xcd/0x100 lib/vsprintf.c:3023
print_time kernel/printk/printk.c:1324 [inline]
info_print_prefix+0x258/0x350 kernel/printk/printk.c:1350
record_print_text+0x143/0x410 kernel/printk/printk.c:1399
printk_get_next_message+0x2ce/0x7c0 kernel/printk/printk.c:2828
console_emit_next_record kernel/printk/printk.c:2868 [inline]
console_flush_all+0x3b0/0xd50 kernel/printk/printk.c:2967
console_unlock+0x10c/0x260 kernel/printk/printk.c:3036
vprintk_emit+0x17f/0x5f0 kernel/printk/printk.c:2303
dev_vprintk_emit drivers/base/core.c:4850 [inline]
dev_printk_emit+0xfb/0x140 drivers/base/core.c:4861
__dev_printk+0xf5/0x270 drivers/base/core.c:4873
_dev_warn+0xe5/0x120 drivers/base/core.c:4917
usb_rx_callback_intf0+0x11c/0x1a0 drivers/media/rc/imon.c:1771
__usb_hcd_giveback_urb+0x359/0x5c0 drivers/usb/core/hcd.c:1650
usb_hcd_giveback_urb+0x389/0x430 drivers/usb/core/hcd.c:1733
dummy_timer+0x1415/0x35f0 drivers/usb/gadget/udc/dummy_hcd.c:1987
call_timer_fn+0x193/0x580 kernel/time/timer.c:1700
expire_timers kernel/time/timer.c:1751 [inline]
__run_timers+0x764/0xb10 kernel/time/timer.c:2022
run_timer_softirq+0x58/0xd0 kernel/time/timer.c:2035
__do_softirq+0x20a/0x94b kernel/softirq.c:553
invoke_softirq kernel/softirq.c:427 [inline]
__irq_exit_rcu kernel/softirq.c:632 [inline]
irq_exit_rcu+0xa7/0x110 kernel/softirq.c:644
sysvec_apic_timer_interrupt+0x8e/0xb0 arch/x86/kernel/apic/apic.c:1076
</IRQ>
<TASK>
asm_sysvec_apic_timer_interrupt+0x1a/0x20 arch/x86/include/asm/idtentry.h:645
RIP: 0010:lock_acquire+0x1ef/0x510 kernel/locking/lockdep.c:5721
Code: c1 05 3d ec d3 7e 83 f8 01 0f 85 b0 02 00 00 9c 58 f6 c4 02 0f 85 9b 02 00 00 48 85 ed 74 01 fb 48 b8 00 00 00 00 00 fc ff df <48> 01 c3 48 c7 03 00 00 00 00 48 c7 43 08 00 00 00 00 48 8b 84 24
RSP: 0018:ffffc9000157fb00 EFLAGS: 00000206
RAX: dffffc0000000000 RBX: 1ffff920002aff62 RCX: 0000000000000001
RDX: 1ffff11021478c2e RSI: ffffffff8687d280 RDI: ffffffff86a687c0
RBP: 0000000000000200 R08: 0000000000000000 R09: fffffbfff16e2144
R10: ffffffff8b710a27 R11: 0000000000000000 R12: 0000000000000000
R13: 0000000000000000 R14: ffffffff87ead2e0 R15: 0000000000000000
rcu_lock_acquire include/linux/rcupdate.h:301 [inline]
rcu_read_lock include/linux/rcupdate.h:747 [inline]
gc_worker+0x24d/0x17e0 net/netfilter/nf_conntrack_core.c:1488
process_one_work+0x884/0x15c0 kernel/workqueue.c:2630
process_scheduled_works kernel/workqueue.c:2703 [inline]
worker_thread+0x8b9/0x1290 kernel/workqueue.c:2784
kthread+0x33c/0x440 kernel/kthread.c:388
ret_from_fork+0x45/0x80 arch/x86/kernel/process.c:147
ret_from_fork_asm+0x11/0x20 arch/x86/entry/entry_64.S:242
</TASK>
INFO: NMI handler (nmi_cpu_backtrace_handler) took too long to run: 3.030 msecs


---
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