[v6.1] INFO: task hung in usb_get_descriptor

[syzbot]

Hello,

syzbot found the following issue on:

HEAD commit: 3b29299e5f60 Linux 6.1.22
git tree: linux-6.1.y
console output: https://syzkaller.appspot.com/x/log.txt?x=17eadc3ec80000
kernel config: https://syzkaller.appspot.com/x/.config?x=bbb9a1f6f7f5a1d9
dashboard link: https://syzkaller.appspot.com/bug?extid=0fbe415eab6118f3ade6
compiler: Debian clang version 15.0.7, GNU ld (GNU Binutils for Debian) 2.35.2
userspace arch: arm64

Unfortunately, I don't have any reproducer for this issue yet.

Downloadable assets:
disk image: https://storage.googleapis.com/syzbot-assets/2affbd06cbfd/disk-3b29299e.raw.xz
vmlinux: https://storage.googleapis.com/syzbot-assets/8b22d1baf827/vmlinux-3b29299e.xz
kernel image: https://storage.googleapis.com/syzbot-assets/d5e3891c88bf/Image-3b29299e.gz.xz

IMPORTANT: if you fix the issue, please add the following tag to the commit:
Reported-by: syzbot+0fbe41...@syzkaller.appspotmail.com

INFO: task kworker/0:3:4318 blocked for more than 143 seconds.
Not tainted 6.1.22-syzkaller #0
"echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message.
task:kworker/0:3 state:D stack:0 pid:4318 ppid:2 flags:0x00000008
Workqueue: usb_hub_wq hub_event
Call trace:
__switch_to+0x320/0x754 arch/arm64/kernel/process.c:553
context_switch kernel/sched/core.c:5241 [inline]
__schedule+0xee4/0x1c98 kernel/sched/core.c:6554
schedule+0xc4/0x170 kernel/sched/core.c:6630
usb_kill_urb+0x1b4/0x32c drivers/usb/core/urb.c:728
usb_start_wait_urb+0x16c/0x414 drivers/usb/core/message.c:64
usb_internal_control_msg drivers/usb/core/message.c:102 [inline]
usb_control_msg+0x228/0x3f8 drivers/usb/core/message.c:153
usb_get_descriptor+0xb4/0x3bc drivers/usb/core/message.c:793
usb_get_device_descriptor+0x9c/0xfc drivers/usb/core/message.c:1071
hub_port_init+0xdc4/0x1eb8 drivers/usb/core/hub.c:4922
hub_port_connect drivers/usb/core/hub.c:5284 [inline]
hub_port_connect_change drivers/usb/core/hub.c:5499 [inline]
port_event drivers/usb/core/hub.c:5655 [inline]
hub_event+0x20b8/0x44a0 drivers/usb/core/hub.c:5737
process_one_work+0x7ac/0x1404 kernel/workqueue.c:2289
worker_thread+0x8e4/0xfec kernel/workqueue.c:2436
kthread+0x24c/0x2d4 kernel/kthread.c:376
ret_from_fork+0x10/0x20 arch/arm64/kernel/entry.S:860

Showing all locks held in the system:
1 lock held by rcu_tasks_kthre/12:
#0: ffff800015754a30 (rcu_tasks.tasks_gp_mutex){+.+.}-{3:3}, at: rcu_tasks_one_gp+0x44/0xcf4 kernel/rcu/tasks.h:510
1 lock held by rcu_tasks_trace/13:
#0: ffff800015755230 (rcu_tasks_trace.tasks_gp_mutex){+.+.}-{3:3}, at: rcu_tasks_one_gp+0x44/0xcf4 kernel/rcu/tasks.h:510
1 lock held by khungtaskd/28:
#0: ffff800015754860 (rcu_read_lock){....}-{1:2}, at: rcu_lock_acquire+0xc/0x44 include/linux/rcupdate.h:305
2 locks held by getty/3988:
#0: ffff0000d3da9098 (&tty->ldisc_sem){++++}-{0:0}, at: ldsem_down_read+0x3c/0x4c drivers/tty/tty_ldsem.c:340
#1: ffff80001ca002f0 (&ldata->atomic_read_lock){+.+.}-{3:3}, at: n_tty_read+0x414/0x1210 drivers/tty/n_tty.c:2177
5 locks held by kworker/0:3/4318:
#0: ffff0000c26a0d38 ((wq_completion)usb_hub_wq){+.+.}-{0:0}, at: process_one_work+0x664/0x1404 kernel/workqueue.c:2262
#1: ffff80001da77c20 ((work_completion)(&hub->events)){+.+.}-{0:0}, at: process_one_work+0x6a8/0x1404 kernel/workqueue.c:2264
#2: ffff0000d0169190 (&dev->mutex){....}-{3:3}, at: device_lock include/linux/device.h:836 [inline]
#2: ffff0000d0169190 (&dev->mutex){....}-{3:3}, at: hub_event+0x1c0/0x44a0 drivers/usb/core/hub.c:5683
#3: ffff0000d016c510 (&port_dev->status_lock){+.+.}-{3:3}, at: usb_lock_port drivers/usb/core/hub.c:3105 [inline]
#3: ffff0000d016c510 (&port_dev->status_lock){+.+.}-{3:3}, at: hub_port_connect drivers/usb/core/hub.c:5251 [inline]
#3: ffff0000d016c510 (&port_dev->status_lock){+.+.}-{3:3}, at: hub_port_connect_change drivers/usb/core/hub.c:5499 [inline]
#3: ffff0000d016c510 (&port_dev->status_lock){+.+.}-{3:3}, at: port_event drivers/usb/core/hub.c:5655 [inline]
#3: ffff0000d016c510 (&port_dev->status_lock){+.+.}-{3:3}, at: hub_event+0x1b78/0x44a0 drivers/usb/core/hub.c:5737
#4: ffff0000cff93668 (hcd->address0_mutex){+.+.}-{3:3}, at: hub_port_connect drivers/usb/core/hub.c:5252 [inline]
#4: ffff0000cff93668 (hcd->address0_mutex){+.+.}-{3:3}, at: hub_port_connect_change drivers/usb/core/hub.c:5499 [inline]
#4: ffff0000cff93668 (hcd->address0_mutex){+.+.}-{3:3}, at: port_event drivers/usb/core/hub.c:5655 [inline]
#4: ffff0000cff93668 (hcd->address0_mutex){+.+.}-{3:3}, at: hub_event+0x1ba0/0x44a0 drivers/usb/core/hub.c:5737
2 locks held by kworker/u4:8/9700:
1 lock held by syz-executor.3/318:
#0: ffff0000cc685b60 (&lo->lo_mutex){+.+.}-{3:3}, at: loop_set_status+0x40/0x804 drivers/block/loop.c:1269
3 locks held by syz-executor.5/342:

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



---
This report is generated by a bot. It may contain errors.
See https://goo.gl/tpsmEJ for more information about syzbot.
syzbot engineers can be reached at syzk...@googlegroups.com.

syzbot will keep track of this issue. See:
https://goo.gl/tpsmEJ#status for how to communicate with syzbot.

[syzbot]

Hello,

syzbot found the following issue on:

HEAD commit: c957cbb87315 Linux 5.15.105
git tree: linux-5.15.y
console output: https://syzkaller.appspot.com/x/log.txt?x=1316b2d9c80000
kernel config: https://syzkaller.appspot.com/x/.config?x=852dc3de44ba1f3f
dashboard link: https://syzkaller.appspot.com/bug?extid=2d5fbfa88b7ba0fce676

compiler: Debian clang version 15.0.7, GNU ld (GNU Binutils for Debian) 2.35.2
userspace arch: arm64

Unfortunately, I don't have any reproducer for this issue yet.

Downloadable assets:

disk image: https://storage.googleapis.com/syzbot-assets/91d0cf1fc5fb/disk-c957cbb8.raw.xz
vmlinux: https://storage.googleapis.com/syzbot-assets/346dc1169521/vmlinux-c957cbb8.xz
kernel image: https://storage.googleapis.com/syzbot-assets/f7005bdc0e20/Image-c957cbb8.gz.xz

IMPORTANT: if you fix the issue, please add the following tag to the commit:

Reported-by: syzbot+2d5fbf...@syzkaller.appspotmail.com

INFO: task kworker/1:2:3270 blocked for more than 144 seconds.
Not tainted 5.15.105-syzkaller #0

"echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message.

task:kworker/1:2 state:D stack: 0 pid: 3270 ppid: 2 flags:0x00000008

Workqueue: usb_hub_wq hub_event
Call trace:

__switch_to+0x308/0x5e8 arch/arm64/kernel/process.c:518
context_switch kernel/sched/core.c:5026 [inline]
__schedule+0xf10/0x1e38 kernel/sched/core.c:6372
schedule+0x11c/0x1c8 kernel/sched/core.c:6455
usb_kill_urb+0x1c0/0x358 drivers/usb/core/urb.c:726

usb_start_wait_urb+0x16c/0x414 drivers/usb/core/message.c:64
usb_internal_control_msg drivers/usb/core/message.c:102 [inline]
usb_control_msg+0x228/0x3f8 drivers/usb/core/message.c:153
usb_get_descriptor+0xb4/0x3bc drivers/usb/core/message.c:793
usb_get_device_descriptor+0x9c/0xfc drivers/usb/core/message.c:1071

hub_port_init+0xdc4/0x1e80 drivers/usb/core/hub.c:4927
hub_port_connect drivers/usb/core/hub.c:5287 [inline]
hub_port_connect_change drivers/usb/core/hub.c:5502 [inline]
port_event drivers/usb/core/hub.c:5648 [inline]
hub_event+0x1f9c/0x48c4 drivers/usb/core/hub.c:5730
process_one_work+0x790/0x11b8 kernel/workqueue.c:2306
worker_thread+0x910/0x1034 kernel/workqueue.c:2453
kthread+0x37c/0x45c kernel/kthread.c:319
ret_from_fork+0x10/0x20 arch/arm64/kernel/entry.S:870

Showing all locks held in the system:

1 lock held by khungtaskd/27:
#0: ffff800014a91660 (rcu_read_lock){....}-{1:2}, at: rcu_lock_acquire+0xc/0x44 include/linux/rcupdate.h:268
5 locks held by kworker/1:2/3270:
#0: ffff0000c28a6938 ((wq_completion)usb_hub_wq){+.+.}-{0:0}, at: process_one_work+0x66c/0x11b8 kernel/workqueue.c:2279
#1: ffff80001e337c00 ((work_completion)(&hub->events)){+.+.}-{0:0}, at: process_one_work+0x6ac/0x11b8 kernel/workqueue.c:2281
#2: ffff0000cf341220 (&dev->mutex){....}-{3:3}, at: device_lock include/linux/device.h:760 [inline]
#2: ffff0000cf341220 (&dev->mutex){....}-{3:3}, at: hub_event+0x1c8/0x48c4 drivers/usb/core/hub.c:5676
#3: ffff0000cf3445d8 (&port_dev->status_lock){+.+.}-{3:3}, at: usb_lock_port drivers/usb/core/hub.c:3091 [inline]
#3: ffff0000cf3445d8 (&port_dev->status_lock){+.+.}-{3:3}, at: hub_port_connect drivers/usb/core/hub.c:5254 [inline]
#3: ffff0000cf3445d8 (&port_dev->status_lock){+.+.}-{3:3}, at: hub_port_connect_change drivers/usb/core/hub.c:5502 [inline]
#3: ffff0000cf3445d8 (&port_dev->status_lock){+.+.}-{3:3}, at: port_event drivers/usb/core/hub.c:5648 [inline]
#3: ffff0000cf3445d8 (&port_dev->status_lock){+.+.}-{3:3}, at: hub_event+0x1a34/0x48c4 drivers/usb/core/hub.c:5730
#4: ffff0000cf23d068 (hcd->address0_mutex){+.+.}-{3:3}, at: hub_port_connect drivers/usb/core/hub.c:5255 [inline]
#4: ffff0000cf23d068 (hcd->address0_mutex){+.+.}-{3:3}, at: hub_port_connect_change drivers/usb/core/hub.c:5502 [inline]
#4: ffff0000cf23d068 (hcd->address0_mutex){+.+.}-{3:3}, at: port_event drivers/usb/core/hub.c:5648 [inline]
#4: ffff0000cf23d068 (hcd->address0_mutex){+.+.}-{3:3}, at: hub_event+0x1a5c/0x48c4 drivers/usb/core/hub.c:5730
1 lock held by syslogd/3571:
1 lock held by klogd/3575:
2 locks held by getty/3739:
#0: ffff0000d4838098 (&tty->ldisc_sem){++++}-{0:0}, at: ldsem_down_read+0x40/0x50 drivers/tty/tty_ldsem.c:340
#1: ffff80001a2ee2e8 (&ldata->atomic_read_lock){+.+.}-{3:3}, at: n_tty_read+0x414/0x1200 drivers/tty/n_tty.c:2147
1 lock held by syz-executor.0/10809:
#0: ffff0000cf341220 (&dev->mutex){....}-{3:3}, at: device_lock include/linux/device.h:760 [inline]
#0: ffff0000cf341220 (&dev->mutex){....}-{3:3}, at: usbdev_open+0x13c/0x6ec drivers/usb/core/devio.c:1030

[syzbot]

syzbot has found a reproducer for the following issue on:

HEAD commit: 8a7f2a5c5aa1 Linux 5.15.110
git tree: linux-5.15.y
console output: https://syzkaller.appspot.com/x/log.txt?x=1084dc4c280000
kernel config: https://syzkaller.appspot.com/x/.config?x=7e93d602da27af41

dashboard link: https://syzkaller.appspot.com/bug?extid=2d5fbfa88b7ba0fce676
compiler: Debian clang version 15.0.7, GNU ld (GNU Binutils for Debian) 2.35.2
userspace arch: arm64

syz repro: https://syzkaller.appspot.com/x/repro.syz?x=11f08d18280000
C reproducer: https://syzkaller.appspot.com/x/repro.c?x=15b3bfb0280000

Downloadable assets:
disk image: https://storage.googleapis.com/syzbot-assets/16bea75b636d/disk-8a7f2a5c.raw.xz
vmlinux: https://storage.googleapis.com/syzbot-assets/3b169e33dcf2/vmlinux-8a7f2a5c.xz
kernel image: https://storage.googleapis.com/syzbot-assets/190d08a00950/Image-8a7f2a5c.gz.xz

IMPORTANT: if you fix the issue, please add the following tag to the commit:
Reported-by: syzbot+2d5fbf...@syzkaller.appspotmail.com

INFO: task kworker/1:3:1953 blocked for more than 143 seconds.
Not tainted 5.15.110-syzkaller #0

"echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message.

task:kworker/1:3 state:D stack: 0 pid: 1953 ppid: 2 flags:0x00000008

Workqueue: usb_hub_wq hub_event
Call trace:
__switch_to+0x308/0x5e8 arch/arm64/kernel/process.c:518
context_switch kernel/sched/core.c:5026 [inline]
__schedule+0xf10/0x1e38 kernel/sched/core.c:6372
schedule+0x11c/0x1c8 kernel/sched/core.c:6455
usb_kill_urb+0x1c0/0x358 drivers/usb/core/urb.c:726
usb_start_wait_urb+0x16c/0x414 drivers/usb/core/message.c:64
usb_internal_control_msg drivers/usb/core/message.c:102 [inline]
usb_control_msg+0x228/0x3f8 drivers/usb/core/message.c:153
usb_get_descriptor+0xb4/0x3bc drivers/usb/core/message.c:793
usb_get_device_descriptor+0x9c/0xfc drivers/usb/core/message.c:1071
hub_port_init+0xdc4/0x1e80 drivers/usb/core/hub.c:4927
hub_port_connect drivers/usb/core/hub.c:5287 [inline]
hub_port_connect_change drivers/usb/core/hub.c:5502 [inline]
port_event drivers/usb/core/hub.c:5648 [inline]
hub_event+0x1f9c/0x48c4 drivers/usb/core/hub.c:5730
process_one_work+0x790/0x11b8 kernel/workqueue.c:2306
worker_thread+0x910/0x1034 kernel/workqueue.c:2453
kthread+0x37c/0x45c kernel/kthread.c:319
ret_from_fork+0x10/0x20 arch/arm64/kernel/entry.S:870

Showing all locks held in the system:
1 lock held by khungtaskd/27:

#0: ffff800014aa1960 (rcu_read_lock){....}-{1:2}, at: rcu_lock_acquire+0xc/0x44 include/linux/rcupdate.h:268
5 locks held by kworker/1:3/1953:
#0: ffff0000c280ad38 ((wq_completion)usb_hub_wq){+.+.}-{0:0}, at: process_one_work+0x66c/0x11b8 kernel/workqueue.c:2279
#1: ffff800021557c00 ((work_completion)(&hub->events)){+.+.}-{0:0}, at: process_one_work+0x6ac/0x11b8 kernel/workqueue.c:2281
#2: ffff0000ced85220 (&dev->mutex){....}-{3:3}, at: device_lock include/linux/device.h:760 [inline]
#2: ffff0000ced85220 (&dev->mutex){....}-{3:3}, at: hub_event+0x1c8/0x48c4 drivers/usb/core/hub.c:5676
#3: ffff0000cede05d8 (&port_dev->status_lock){+.+.}-{3:3}, at: usb_lock_port drivers/usb/core/hub.c:3091 [inline]
#3: ffff0000cede05d8 (&port_dev->status_lock){+.+.}-{3:3}, at: hub_port_connect drivers/usb/core/hub.c:5254 [inline]
#3: ffff0000cede05d8 (&port_dev->status_lock){+.+.}-{3:3}, at: hub_port_connect_change drivers/usb/core/hub.c:5502 [inline]
#3: ffff0000cede05d8 (&port_dev->status_lock){+.+.}-{3:3}, at: port_event drivers/usb/core/hub.c:5648 [inline]
#3: ffff0000cede05d8 (&port_dev->status_lock){+.+.}-{3:3}, at: hub_event+0x1a34/0x48c4 drivers/usb/core/hub.c:5730
#4: ffff0000ce7bb468 (hcd->address0_mutex){+.+.}-{3:3}, at: hub_port_connect drivers/usb/core/hub.c:5255 [inline]
#4: ffff0000ce7bb468 (hcd->address0_mutex){+.+.}-{3:3}, at: hub_port_connect_change drivers/usb/core/hub.c:5502 [inline]
#4: ffff0000ce7bb468 (hcd->address0_mutex){+.+.}-{3:3}, at: port_event drivers/usb/core/hub.c:5648 [inline]
#4: ffff0000ce7bb468 (hcd->address0_mutex){+.+.}-{3:3}, at: hub_event+0x1a5c/0x48c4 drivers/usb/core/hub.c:5730
2 locks held by getty/3725:
#0: ffff0000d2ec3098 (&tty->ldisc_sem){++++}-{0:0}, at: ldsem_down_read+0x40/0x50 drivers/tty/tty_ldsem.c:340
#1: ffff80001a35b2e8 (&ldata->atomic_read_lock){+.+.}-{3:3}, at: n_tty_read+0x414/0x1200 drivers/tty/n_tty.c:2147
1 lock held by sshd/4002:
#0: ffff0001b4810d18 (&rq->__lock){-.-.}-{2:2}, at: raw_spin_rq_lock_nested kernel/sched/core.c:475 [inline]
#0: ffff0001b4810d18 (&rq->__lock){-.-.}-{2:2}, at: raw_spin_rq_lock kernel/sched/sched.h:1326 [inline]
#0: ffff0001b4810d18 (&rq->__lock){-.-.}-{2:2}, at: rq_lock kernel/sched/sched.h:1621 [inline]
#0: ffff0001b4810d18 (&rq->__lock){-.-.}-{2:2}, at: __schedule+0x328/0x1e38 kernel/sched/core.c:6286
7 locks held by syz-executor194/31811:

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



---
If you want syzbot to run the reproducer, reply with:
#syz test: git://repo/address.git branch-or-commit-hash
If you attach or paste a git patch, syzbot will apply it before testing.

[syzbot]

syzbot has found a reproducer for the following issue on:

HEAD commit: ca48fc16c493 Linux 6.1.27
git tree: linux-6.1.y
console output: https://syzkaller.appspot.com/x/log.txt?x=118de25c280000
kernel config: https://syzkaller.appspot.com/x/.config?x=aea4bb7802570997

dashboard link: https://syzkaller.appspot.com/bug?extid=0fbe415eab6118f3ade6
compiler: Debian clang version 15.0.7, GNU ld (GNU Binutils for Debian) 2.35.2
userspace arch: arm64

syz repro: https://syzkaller.appspot.com/x/repro.syz?x=1063176a280000
C reproducer: https://syzkaller.appspot.com/x/repro.c?x=111c46b8280000

Downloadable assets:
disk image: https://storage.googleapis.com/syzbot-assets/ec11c1903c52/disk-ca48fc16.raw.xz
vmlinux: https://storage.googleapis.com/syzbot-assets/8ce41c1ad391/vmlinux-ca48fc16.xz
kernel image: https://storage.googleapis.com/syzbot-assets/affba5631cad/Image-ca48fc16.gz.xz

IMPORTANT: if you fix the issue, please add the following tag to the commit:
Reported-by: syzbot+0fbe41...@syzkaller.appspotmail.com

INFO: task kworker/0:0:7 blocked for more than 143 seconds.
Not tainted 6.1.27-syzkaller #0

"echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message.

task:kworker/0:0 state:D stack:0 pid:7 ppid:2 flags:0x00000008

Workqueue: usb_hub_wq hub_event
Call trace:
__switch_to+0x320/0x754 arch/arm64/kernel/process.c:553
context_switch kernel/sched/core.c:5241 [inline]
__schedule+0xee4/0x1c98 kernel/sched/core.c:6554
schedule+0xc4/0x170 kernel/sched/core.c:6630
usb_kill_urb+0x1b4/0x32c drivers/usb/core/urb.c:728
usb_start_wait_urb+0x16c/0x414 drivers/usb/core/message.c:64
usb_internal_control_msg drivers/usb/core/message.c:102 [inline]
usb_control_msg+0x228/0x3f8 drivers/usb/core/message.c:153
usb_get_descriptor+0xb4/0x3bc drivers/usb/core/message.c:793
usb_get_device_descriptor+0x9c/0xfc drivers/usb/core/message.c:1071
hub_port_init+0xdc4/0x1eb8 drivers/usb/core/hub.c:4922
hub_port_connect drivers/usb/core/hub.c:5284 [inline]
hub_port_connect_change drivers/usb/core/hub.c:5499 [inline]
port_event drivers/usb/core/hub.c:5655 [inline]
hub_event+0x20b8/0x44a0 drivers/usb/core/hub.c:5737
process_one_work+0x7ac/0x1404 kernel/workqueue.c:2289
worker_thread+0x8e4/0xfec kernel/workqueue.c:2436

kthread+0x250/0x2d8 kernel/kthread.c:376

ret_from_fork+0x10/0x20 arch/arm64/kernel/entry.S:860

Showing all locks held in the system:

5 locks held by kworker/0:0/7:
#0: ffff0000c464e938 ((wq_completion)usb_hub_wq){+.+.}-{0:0}, at: process_one_work+0x664/0x1404 kernel/workqueue.c:2262
#1: ffff800019b37c20 ((work_completion)(&hub->events)){+.+.}-{0:0}, at: process_one_work+0x6a8/0x1404 kernel/workqueue.c:2264
#2: ffff0000d1c2a190 (&dev->mutex){....}-{3:3}, at: device_lock include/linux/device.h:836 [inline]
#2: ffff0000d1c2a190 (&dev->mutex){....}-{3:3}, at: hub_event+0x1c0/0x44a0 drivers/usb/core/hub.c:5683
#3: ffff0000d1c2d510 (&port_dev->status_lock){+.+.}-{3:3}, at: usb_lock_port drivers/usb/core/hub.c:3105 [inline]
#3: ffff0000d1c2d510 (&port_dev->status_lock){+.+.}-{3:3}, at: hub_port_connect drivers/usb/core/hub.c:5251 [inline]
#3: ffff0000d1c2d510 (&port_dev->status_lock){+.+.}-{3:3}, at: hub_port_connect_change drivers/usb/core/hub.c:5499 [inline]
#3: ffff0000d1c2d510 (&port_dev->status_lock){+.+.}-{3:3}, at: port_event drivers/usb/core/hub.c:5655 [inline]
#3: ffff0000d1c2d510 (&port_dev->status_lock){+.+.}-{3:3}, at: hub_event+0x1b78/0x44a0 drivers/usb/core/hub.c:5737
#4: ffff0000d17cac68 (hcd->address0_mutex){+.+.}-{3:3}, at: hub_port_connect drivers/usb/core/hub.c:5252 [inline]
#4: ffff0000d17cac68 (hcd->address0_mutex){+.+.}-{3:3}, at: hub_port_connect_change drivers/usb/core/hub.c:5499 [inline]
#4: ffff0000d17cac68 (hcd->address0_mutex){+.+.}-{3:3}, at: port_event drivers/usb/core/hub.c:5655 [inline]
#4: ffff0000d17cac68 (hcd->address0_mutex){+.+.}-{3:3}, at: hub_event+0x1ba0/0x44a0 drivers/usb/core/hub.c:5737

1 lock held by rcu_tasks_kthre/12:

#0: ffff800015764d30 (rcu_tasks.tasks_gp_mutex){+.+.}-{3:3}, at: rcu_tasks_one_gp+0x44/0xcf4 kernel/rcu/tasks.h:510

1 lock held by rcu_tasks_trace/13:

#0: ffff800015765530 (rcu_tasks_trace.tasks_gp_mutex){+.+.}-{3:3}, at: rcu_tasks_one_gp+0x44/0xcf4 kernel/rcu/tasks.h:510

1 lock held by khungtaskd/28:

#0: ffff800015764b60 (rcu_read_lock){....}-{1:2}, at: rcu_lock_acquire+0xc/0x44 include/linux/rcupdate.h:305
2 locks held by getty/3980:
#0: ffff0000d6002098 (&tty->ldisc_sem){++++}-{0:0}, at: ldsem_down_read+0x3c/0x4c drivers/tty/tty_ldsem.c:340
#1: ffff80001ca302f0 (&ldata->atomic_read_lock){+.+.}-{3:3}, at: n_tty_read+0x414/0x1210 drivers/tty/n_tty.c:2177