[syzbot] [media?] [usb?] INFO: task hung in vb2_video_unregister_device

syzbot
2024-02-28T05:03:17Z

Hello,

syzbot found the following issue on:

HEAD commit: 9abbc24128bc Merge branch 'for-next/core' into for-kernelci
git tree: git://git.kernel.org/pub/scm/linux/kernel/git/arm64/linux.git for-kernelci
console output: https://syzkaller.appspot.com/x/log.txt?x=12073622180000
kernel config: https://syzkaller.appspot.com/x/.config?x=af5c6c699e57bbb3
dashboard link: https://syzkaller.appspot.com/bug?extid=2622b51b35f91a00ea18
compiler: Debian clang version 15.0.6, GNU ld (GNU Binutils for Debian) 2.40
userspace arch: arm64
syz repro: https://syzkaller.appspot.com/x/repro.syz?x=132173d2180000
C reproducer: https://syzkaller.appspot.com/x/repro.c?x=10d7ec54180000

Downloadable assets:
disk image: https://storage.googleapis.com/syzbot-assets/ce13ec3ed5ad/disk-9abbc241.raw.xz
vmlinux: https://storage.googleapis.com/syzbot-assets/256cbd314121/vmlinux-9abbc241.xz
kernel image: https://storage.googleapis.com/syzbot-assets/0af86fb52109/Image-9abbc241.gz.xz

IMPORTANT: if you fix the issue, please add the following tag to the commit:
Reported-by: syzbot+2622b51b35f91a00ea18@syzkaller.appspotmail.com

INFO: task kworker/0:1:10 blocked for more than 143 seconds.
Tainted: G B 6.8.0-rc5-syzkaller-g9abbc24128bc #0
"echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message.
task:kworker/0:1 state:D stack:0 pid:10 tgid:10 ppid:2 flags:0x00000008
Workqueue: usb_hub_wq hub_event
Call trace:
__switch_to+0x314/0x560 arch/arm64/kernel/process.c:553
context_switch kernel/sched/core.c:5400 [inline]
__schedule+0x1498/0x24b4 kernel/sched/core.c:6727
__schedule_loop kernel/sched/core.c:6802 [inline]
schedule+0xb8/0x19c kernel/sched/core.c:6817
schedule_preempt_disabled+0x18/0x2c kernel/sched/core.c:6874
__mutex_lock_common+0xbd8/0x21a0 kernel/locking/mutex.c:684
__mutex_lock kernel/locking/mutex.c:752 [inline]
mutex_lock_nested+0x2c/0x38 kernel/locking/mutex.c:804
vb2_video_unregister_device+0x11c/0x1dc drivers/media/common/videobuf2/videobuf2-v4l2.c:1269
usbtv_video_free+0x4c/0x84 drivers/media/usb/usbtv/usbtv-video.c:970
usbtv_disconnect+0x6c/0xc4 drivers/media/usb/usbtv/usbtv-core.c:138
usb_unbind_interface+0x1a4/0x758 drivers/usb/core/driver.c:461
device_remove drivers/base/dd.c:569 [inline]
__device_release_driver drivers/base/dd.c:1272 [inline]
device_release_driver_internal+0x440/0x6a0 drivers/base/dd.c:1295
device_release_driver+0x28/0x38 drivers/base/dd.c:1318
bus_remove_device+0x314/0x3b4 drivers/base/bus.c:574
device_del+0x480/0x87c drivers/base/core.c:3828
usb_disable_device+0x354/0x760 drivers/usb/core/message.c:1416
usb_disconnect+0x290/0x808 drivers/usb/core/hub.c:2267
hub_port_connect drivers/usb/core/hub.c:5323 [inline]
hub_port_connect_change drivers/usb/core/hub.c:5623 [inline]
port_event drivers/usb/core/hub.c:5783 [inline]
hub_event+0x18ec/0x435c drivers/usb/core/hub.c:5865
process_one_work+0x694/0x1204 kernel/workqueue.c:2633
process_scheduled_works kernel/workqueue.c:2706 [inline]
worker_thread+0x970/0xef4 kernel/workqueue.c:2787
kthread+0x288/0x310 kernel/kthread.c:388
ret_from_fork+0x10/0x20 arch/arm64/kernel/entry.S:860
INFO: lockdep is turned off.

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