[syzbot] [wireguard?] INFO: task hung in wg_netns_pre_exit (4)

[syzbot]

Hello,

syzbot found the following issue on:

HEAD commit: 4a4be1ad3a6e Revert "vfs: Delete the associated dentry whe..
git tree: upstream
console output: https://syzkaller.appspot.com/x/log.txt?x=14003162980000
kernel config: https://syzkaller.appspot.com/x/.config?x=b9016f104992d69c
dashboard link: https://syzkaller.appspot.com/bug?extid=1d5c9cd5bcdce13e618e
compiler: Debian clang version 15.0.6, GNU ld (GNU Binutils for Debian) 2.40

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

Downloadable assets:
disk image: https://storage.googleapis.com/syzbot-assets/fd3b4fa0291b/disk-4a4be1ad.raw.xz
vmlinux: https://storage.googleapis.com/syzbot-assets/d58e4ceaeff3/vmlinux-4a4be1ad.xz
kernel image: https://storage.googleapis.com/syzbot-assets/4df89f1b7d3b/bzImage-4a4be1ad.xz

IMPORTANT: if you fix the issue, please add the following tag to the commit:
Reported-by: syzbot+1d5c9c...@syzkaller.appspotmail.com

INFO: task kworker/u8:0:11 blocked for more than 143 seconds.
Not tainted 6.10.0-rc1-syzkaller-00027-g4a4be1ad3a6e #0
"echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message.
task:kworker/u8:0 state:D stack:20632 pid:11 tgid:11 ppid:2 flags:0x00004000
Workqueue: netns cleanup_net
Call Trace:
<TASK>
context_switch kernel/sched/core.c:5408 [inline]
__schedule+0x17e8/0x4a20 kernel/sched/core.c:6745
__schedule_loop kernel/sched/core.c:6822 [inline]
schedule+0x14b/0x320 kernel/sched/core.c:6837
schedule_preempt_disabled+0x13/0x30 kernel/sched/core.c:6894
__mutex_lock_common kernel/locking/mutex.c:684 [inline]
__mutex_lock+0x6a4/0xd70 kernel/locking/mutex.c:752
wg_netns_pre_exit+0x1f/0x1e0 drivers/net/wireguard/device.c:414
ops_pre_exit_list net/core/net_namespace.c:163 [inline]
cleanup_net+0x617/0xcc0 net/core/net_namespace.c:620
process_one_work kernel/workqueue.c:3231 [inline]
process_scheduled_works+0xa2e/0x1830 kernel/workqueue.c:3312
worker_thread+0x86d/0xd70 kernel/workqueue.c:3393
kthread+0x2f2/0x390 kernel/kthread.c:389
ret_from_fork+0x4d/0x80 arch/x86/kernel/process.c:147
ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:244
</TASK>
INFO: task kworker/1:1:45 blocked for more than 144 seconds.
Not tainted 6.10.0-rc1-syzkaller-00027-g4a4be1ad3a6e #0
"echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message.
task:kworker/1:1 state:D stack:22064 pid:45 tgid:45 ppid:2 flags:0x00004000
Workqueue: events linkwatch_event
Call Trace:
<TASK>
context_switch kernel/sched/core.c:5408 [inline]
__schedule+0x17e8/0x4a20 kernel/sched/core.c:6745
__schedule_loop kernel/sched/core.c:6822 [inline]
schedule+0x14b/0x320 kernel/sched/core.c:6837
schedule_preempt_disabled+0x13/0x30 kernel/sched/core.c:6894
__mutex_lock_common kernel/locking/mutex.c:684 [inline]
__mutex_lock+0x6a4/0xd70 kernel/locking/mutex.c:752


---
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.

If the report is already addressed, let syzbot know by replying with:
#syz fix: exact-commit-title

If you want to overwrite report's subsystems, reply with:
#syz set subsystems: new-subsystem
(See the list of subsystem names on the web dashboard)

If the report is a duplicate of another one, reply with:
#syz dup: exact-subject-of-another-report

If you want to undo deduplication, reply with:
#syz undup

[Tetsuo Handa]

#syz fix: net/sched: act_api: fix possible infinite loop in tcf_idr_check_alloc()