Netdev List
 help / color / mirror / Atom feed
From: Pablo Neira Ayuso <pablo@netfilter.org>
To: Florian Westphal <fw@strlen.de>
Cc: netdev@vger.kernel.org, Paolo Abeni <pabeni@redhat.com>,
	"David S. Miller" <davem@davemloft.net>,
	Eric Dumazet <edumazet@google.com>,
	Jakub Kicinski <kuba@kernel.org>,
	netfilter-devel@vger.kernel.org
Subject: Re: [PATCH net 4/9] netfilter: nf_conntrack_sip: validate skb_dst() before accessing it
Date: Wed, 1 Jul 2026 13:01:54 +0200	[thread overview]
Message-ID: <akTzomC4Qz8u8teJ@chamomile> (raw)
In-Reply-To: <akS1W7XGQ3LiP0LC@strlen.de>

On Wed, Jul 01, 2026 at 08:36:11AM +0200, Florian Westphal wrote:
> Florian Westphal <fw@strlen.de> wrote:
> > From: Pablo Neira Ayuso <pablo@netfilter.org>
> > 
> > tc ingress and openvswitch do not guarantee routing information to be
> > available. These subsystems use the conntrack helper infrastructure, and
> > the SIP helper relies on the skb_dst() to be present if
> > sip_external_media is set to 1 (which is disabled by default as a module
> > parameter).
> 
> The sashiko drive-by appears real, I submitted a patch for it.
> Its not a regression added by this patch but a unrelated issue.
> 
> https://patchwork.ozlabs.org/project/netfilter-devel/patch/20260701062922.9660-1-fw@strlen.de/

Is skb_ensure_writable() bogus here?

As you said, skb is already linearized. As for clones, they should
only happen in br_netfilter? In such case, it should be br_netfilter
that should be audited not to pass cloned skbuffs before calling the
inet hooks.

  reply	other threads:[~2026-07-01 11:01 UTC|newest]

Thread overview: 16+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2026-06-30  4:52 [PATCH net 0/9] netfilter: updates for net Florian Westphal
2026-06-30  4:52 ` [PATCH net 1/9] netfilter: nf_conntrack_expect: zero at allocation time Florian Westphal
2026-07-01 17:10   ` patchwork-bot+netdevbpf
2026-06-30  4:52 ` [PATCH net 2/9] netfilter: nft_set_pipapo: don't leak bad clone into future transaction Florian Westphal
2026-06-30  4:52 ` [PATCH net 3/9] netfilter: ipset: fix race between dump and ip_set_list resize Florian Westphal
2026-07-01  5:09   ` Florian Westphal
2026-06-30  4:52 ` [PATCH net 4/9] netfilter: nf_conntrack_sip: validate skb_dst() before accessing it Florian Westphal
2026-07-01  6:36   ` Florian Westphal
2026-07-01 11:01     ` Pablo Neira Ayuso [this message]
2026-07-01 12:23       ` Pablo Neira Ayuso
2026-06-30  4:52 ` [PATCH net 5/9] netfilter: nfnetlink_cthelper: cap to maximum number of expectation per master Florian Westphal
2026-07-01  5:04   ` Florian Westphal
2026-06-30  4:52 ` [PATCH net 6/9] netfilter: nft_fib: reject fib expression on the netdev egress hook Florian Westphal
2026-06-30  4:52 ` [PATCH net 7/9] netfilter: nfnetlink_queue: restrict writes to network header Florian Westphal
2026-06-30  4:52 ` [PATCH net 8/9] netfilter: nftables: restrict linklayer and network header writes Florian Westphal
2026-06-30  4:52 ` [PATCH net 9/9] netfilter: nftables: restrict checkum update offset Florian Westphal

Reply instructions:

You may reply publicly to this message via plain-text email
using any one of the following methods:

* Save the following mbox file, import it into your mail client,
  and reply-to-all from there: mbox

  Avoid top-posting and favor interleaved quoting:
  https://en.wikipedia.org/wiki/Posting_style#Interleaved_style

* Reply using the --to, --cc, and --in-reply-to
  switches of git-send-email(1):

  git send-email \
    --in-reply-to=akTzomC4Qz8u8teJ@chamomile \
    --to=pablo@netfilter.org \
    --cc=davem@davemloft.net \
    --cc=edumazet@google.com \
    --cc=fw@strlen.de \
    --cc=kuba@kernel.org \
    --cc=netdev@vger.kernel.org \
    --cc=netfilter-devel@vger.kernel.org \
    --cc=pabeni@redhat.com \
    /path/to/YOUR_REPLY

  https://kernel.org/pub/software/scm/git/docs/git-send-email.html

* If your mail client supports setting the In-Reply-To header
  via mailto: links, try the mailto: link
Be sure your reply has a Subject: header at the top and a blank line before the message body.
This is a public inbox, see mirroring instructions
for how to clone and mirror all data and code used for this inbox