[v5.15] INFO: task hung in ip6gre_exit_batch_net

[syzbot]

Hello,

syzbot found the following issue on:

HEAD commit: 83655231580b Linux 5.15.159
git tree: linux-5.15.y
console output: https://syzkaller.appspot.com/x/log.txt?x=1664cedc980000
kernel config: https://syzkaller.appspot.com/x/.config?x=ea870d7ee19c0a5c
dashboard link: https://syzkaller.appspot.com/bug?extid=ad0624e64b8fc5e0745a
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/d5444b7453a0/disk-83655231.raw.xz
vmlinux: https://storage.googleapis.com/syzbot-assets/76ae736a43a3/vmlinux-83655231.xz
kernel image: https://storage.googleapis.com/syzbot-assets/2540e00ba747/bzImage-83655231.xz

IMPORTANT: if you fix the issue, please add the following tag to the commit:
Reported-by: syzbot+ad0624...@syzkaller.appspotmail.com

INFO: task kworker/u4:2:154 blocked for more than 143 seconds.
Not tainted 5.15.159-syzkaller #0
"echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message.
task:kworker/u4:2 state:D stack:19520 pid: 154 ppid: 2 flags:0x00004000
Workqueue: netns cleanup_net
Call Trace:
<TASK>
context_switch kernel/sched/core.c:5030 [inline]
__schedule+0x12c4/0x45b0 kernel/sched/core.c:6376
schedule+0x11b/0x1f0 kernel/sched/core.c:6459
schedule_preempt_disabled+0xf/0x20 kernel/sched/core.c:6518
__mutex_lock_common+0xe34/0x25a0 kernel/locking/mutex.c:669
__mutex_lock kernel/locking/mutex.c:729 [inline]
mutex_lock_nested+0x17/0x20 kernel/locking/mutex.c:743
ip6gre_exit_batch_net+0xc0/0x460 net/ipv6/ip6_gre.c:1647
ops_exit_list net/core/net_namespace.c:177 [inline]
cleanup_net+0x763/0xb60 net/core/net_namespace.c:599
process_one_work+0x8a1/0x10c0 kernel/workqueue.c:2310
worker_thread+0xaca/0x1280 kernel/workqueue.c:2457


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