Re: [syzbot] [net?] WARNING: bad unlock balance in do_setlink

[Aleksandr Nogikh]

On Mon, Apr 7, 2025 at 6:13 PM 'Kuniyuki Iwashima' via syzkaller-bugs
<syzkaller-bugs@xxxxxxxxxxxxxxxx> wrote:
>
> From: Stanislav Fomichev <stfomichev@xxxxxxxxx>
> Date: Mon, 7 Apr 2025 07:19:54 -0700
> > On 04/07, syzbot wrote:
> > > Hello,
> > >
> > > syzbot has tested the proposed patch but the reproducer is still triggering an issue:
> > > unregister_netdevice: waiting for DEV to become free
> > >
> > > unregister_netdevice: waiting for batadv0 to become free. Usage count = 3
> >
> > So it does fix the lock unbalance issue, but now there is a hang?
>
> I think this is an orthogonal issue.
>
> I saw this in another report as well.
> https://lore.kernel.org/netdev/67f208ea.050a0220.0a13.025b.GAE@xxxxxxxxxx/
>
> syzbot may want to find a better way to filter this kind of noise.
>

Syzbot treats this message as a problem worthy of reporting since a
long time (Cc'd Dmitry who may remember the context):
https://github.com/google/syzkaller/commit/7a67784ca8bdc3b26cce2f0ec9a40d2dd9ec9396

Since v6.15-rc1, we do observe it happen at least 10x more often than
before, both during fuzzing and while processing #syz test commands:
https://syzkaller.appspot.com/bug?extid=881d65229ca4f9ae8c84

-- 
Aleksandr