From: Florian Westphal <fw@strlen.de>
To: Steffen Klassert <steffen.klassert@secunet.com>
Cc: Qi Tang <tpluszz77@gmail.com>,
Herbert Xu <herbert@gondor.apana.org.au>,
"David S . Miller" <davem@davemloft.net>,
Eric Dumazet <edumazet@google.com>,
Jakub Kicinski <kuba@kernel.org>, Paolo Abeni <pabeni@redhat.com>,
Simon Horman <horms@kernel.org>, David Ahern <dsahern@kernel.org>,
netdev@vger.kernel.org, stable@vger.kernel.org
Subject: Re: [PATCH v2] xfrm: delay dev_put in xfrm_input to after transport reinject
Date: Thu, 2 Apr 2026 12:54:37 +0200 [thread overview]
Message-ID: <ac5K7S3dBsINFafg@strlen.de> (raw)
In-Reply-To: <ac5GnMeqSeNlzBp7@secunet.com>
Steffen Klassert <steffen.klassert@secunet.com> wrote:
> On Tue, Mar 31, 2026 at 05:27:37PM +0800, Qi Tang wrote:
> > int xfrm4_transport_finish(struct sk_buff *skb, int async)
> > {
> > struct xfrm_offload *xo = xfrm_offload(skb);
> > @@ -74,7 +96,8 @@ int xfrm4_transport_finish(struct sk_buff *skb, int async)
> >
> > NF_HOOK(NFPROTO_IPV4, NF_INET_PRE_ROUTING,
> > dev_net(skb->dev), NULL, skb, skb->dev, NULL,
> > - xfrm4_rcv_encap_finish);
> > + async ? xfrm4_rcv_encap_finish_async :
> > + xfrm4_rcv_encap_finish);
>
> What happens if the PRE_ROUTING hook returns NF_DROP, NF_QUEUE, or
> NF_STOLEN before the okfn runs? Looks like we leak the dev refcnt
> then.
Yes, no okfn is run in those cases.
I'd suggest do drop the refcount after NF_HOOK, i.e. something like:
dev = skb->dev;
NF_HOOK(NFPROTO_IPV4, NF_INET_PRE_ROUTING,
...
if (async)
dev_put(dev);
Thats easier to follow.
next prev parent reply other threads:[~2026-04-02 10:54 UTC|newest]
Thread overview: 4+ messages / expand[flat|nested] mbox.gz Atom feed top
2026-03-31 9:27 [PATCH v2] xfrm: delay dev_put in xfrm_input to after transport reinject Qi Tang
2026-04-02 10:36 ` Steffen Klassert
2026-04-02 10:54 ` Florian Westphal [this message]
2026-04-02 11:26 ` Qi Tang
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