From: Pablo Neira Ayuso <pablo@netfilter.org>
To: Rundong Ge <rdong.ge@gmail.com>
Cc: kadlec@blackhole.kfki.hu, fw@strlen.de,
roopa@cumulusnetworks.com, nikolay@cumulusnetworks.com,
davem@davemloft.net, netfilter-devel@vger.kernel.org,
coreteam@netfilter.org, bridge@lists.linux-foundation.org,
netdev@vger.kernel.org, linux-kernel@vger.kernel.org
Subject: Re: [PATCH] netfilter:bridge: Hold bridge dev for fake_rtable to avoid the dangling pointer
Date: Wed, 3 Apr 2019 19:44:41 +0200 [thread overview]
Message-ID: <20190403174441.2l7xyk5o2hftrdm3@salvia> (raw)
In-Reply-To: <20190402125609.30313-1-rdong.ge@gmail.com>
On Tue, Apr 02, 2019 at 12:56:09PM +0000, Rundong Ge wrote:
> Problem:
> When bridge-nf-call-iptables is enabled, skb_dst(skb) of packets that
> in the nfqueue may be a dangling pointer if user delete the bridge.
> Because packets go through the br_nf_pre_routing_finish will set the dst
> pointer to the br->fake_rtable. But the br struct will be freed
> without the reference check for these skbs.
>
> User impact:
> Kernel panic may happen when user delete the bridge if there are
> continuous traffics go through the nfqueue.
> Here is a panic in my device which using kernel v3.10.
This kernel is _very old_.
Could you provide the steps to reproduce this issue?
Holding the device doesn't seem the way to go to me, we have a of
netdevice_notifier that is dropping packets for an interface that is
gone in nfnetlink_queue. We also drop packets whenever a hook in gone.
So I wonder if this is still a problem in mainline kernels.
next prev parent reply other threads:[~2019-04-03 17:44 UTC|newest]
Thread overview: 4+ messages / expand[flat|nested] mbox.gz Atom feed top
2019-04-02 12:56 [PATCH] netfilter:bridge: Hold bridge dev for fake_rtable to avoid the dangling pointer Rundong Ge
2019-04-03 17:44 ` Pablo Neira Ayuso [this message]
2019-04-09 6:33 ` Rundong Ge
2019-04-18 9:58 ` Rundong Ge
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