[syzbot] [fs?] WARNING in nsproxy_ns_active_put

[syzbot]

syzbot has bisected this issue to:

commit 3a18f809184bc5a1cfad7cde5b8b026e2ff61587
Author: Christian Brauner <brauner at kernel.org>
Date:   Wed Oct 29 12:20:24 2025 +0000

    ns: add active reference count

bisection log:  https://syzkaller.appspot.com/x/bisect.txt?x=11a350b4580000
start commit:   9c0826a5d9aa Add linux-next specific files for 20251107
git tree:       linux-next
final oops:     https://syzkaller.appspot.com/x/report.txt?x=13a350b4580000
console output: https://syzkaller.appspot.com/x/log.txt?x=15a350b4580000
kernel config:  https://syzkaller.appspot.com/x/.config?x=f2ebeee52bf052b8
dashboard link: https://syzkaller.appspot.com/bug?extid=0b2e79f91ff6579bfa5b
syz repro:      https://syzkaller.appspot.com/x/repro.syz?x=1639d084580000
C reproducer:   https://syzkaller.appspot.com/x/repro.c?x=1625aa92580000

Reported-by: syzbot+0b2e79f91ff6579bfa5b at syzkaller.appspotmail.com
Fixes: 3a18f809184b ("ns: add active reference count")

For information about bisection process see: https://goo.gl/tpsmEJ#bisection