From: Florian Westphal <fw@strlen.de>
To: Eric Dumazet <edumazet@google.com>
Cc: Jakub Kicinski <kuba@kernel.org>,
syzbot <syzbot+4393c47753b7808dac7d@syzkaller.appspotmail.com>,
coreteam@netfilter.org, davem@davemloft.net, horms@kernel.org,
kadlec@netfilter.org, linux-kernel@vger.kernel.org,
netdev@vger.kernel.org, netfilter-devel@vger.kernel.org,
pabeni@redhat.com, pablo@netfilter.org, phil@nwl.cc,
syzkaller-bugs@googlegroups.com
Subject: Re: [syzbot] [netfilter?] WARNING in nf_conntrack_cleanup_net_list
Date: Sat, 13 Dec 2025 14:40:20 +0100 [thread overview]
Message-ID: <aT1sxJHiK1mcrXaE@strlen.de> (raw)
In-Reply-To: <CANn89i+V0XfUMjo5azSAkcr6EKucQFs6fv6mpNeL3rN41SsTzg@mail.gmail.com>
Eric Dumazet <edumazet@google.com> wrote:
> > > I looked around last night but couldn't find an skb stuck anywhere.
> > > The nf_conntrack_net->count was == 1
> >
> > Its caused skb skb fraglist skbs that still hold nf_conn references
> > on the softnet data defer lists.
> >
> > setting net.core.skb_defer_max=0 makes the hang disappear for me.
>
> What kind of packets ? TCP ones ?
UDP, but I can't say yet if thats an udp specific issue or not.
(the packets are generated via ip_defrag.c).
next prev parent reply other threads:[~2025-12-13 13:40 UTC|newest]
Thread overview: 7+ messages / expand[flat|nested] mbox.gz Atom feed top
2025-12-11 18:38 [syzbot] [netfilter?] WARNING in nf_conntrack_cleanup_net_list syzbot
2025-12-12 23:07 ` Jakub Kicinski
2025-12-13 13:27 ` Florian Westphal
2025-12-13 13:30 ` Eric Dumazet
2025-12-13 13:40 ` Florian Westphal [this message]
2025-12-13 13:58 ` Eric Dumazet
2025-12-13 18:54 ` Florian Westphal
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