[syzbot] [fs?] WARNING in nsproxy_ns_active_put

[Christian Brauner]

On Sun, Nov 09, 2025 at 12:24:02AM -0800, syzbot wrote:
> 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

#syz test: https://github.com/brauner/linux.git namespace-6.19