The Linux Kernel Mailing List
 help / color / mirror / Atom feed
From: Florian Westphal <fw@strlen.de>
To: Yizhou Zhao <zhaoyz24@mails.tsinghua.edu.cn>
Cc: netfilter-devel@vger.kernel.org,
	Pablo Neira Ayuso <pablo@netfilter.org>,
	Phil Sutter <phil@nwl.cc>,
	"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>,
	coreteam@netfilter.org, netdev@vger.kernel.org,
	linux-kernel@vger.kernel.org,
	Yuxiang Yang <yangyx22@mails.tsinghua.edu.cn>,
	Ao Wang <wangao@seu.edu.cn>, Xuewei Feng <fengxw06@126.com>,
	Qi Li <qli01@tsinghua.edu.cn>, Ke Xu <xuke@tsinghua.edu.cn>,
	stable@vger.kernel.org
Subject: Re: [PATCH nf] netfilter: nf_conncount: fix zone comparison in tuple dedup
Date: Tue, 7 Jul 2026 16:58:21 +0200	[thread overview]
Message-ID: <ak0UDVc4gZbfzrtM@strlen.de> (raw)
In-Reply-To: <20260706114820.74006-1-zhaoyz24@mails.tsinghua.edu.cn>

Yizhou Zhao <zhaoyz24@mails.tsinghua.edu.cn> wrote:
> The "already exists" dedup logic in __nf_conncount_add() decides
> whether a connection has already been counted and can be skipped instead
> of incrementing the connlimit count.  It compares the conntrack zone of a
> list entry with the zone of the connection being added using
> nf_ct_zone_id() and nf_ct_zone_equal(), passing conn->zone.dir or
> zone->dir as the direction argument.

Right, thats bogus.

> @@ -211,8 +220,10 @@ static int __nf_conncount_add(struct net *net,
>  			/* Not found, but might be about to be confirmed */
>  			if (PTR_ERR(found) == -EAGAIN) {
>  				if (nf_ct_tuple_equal(&conn->tuple, &tuple) &&
> -				    nf_ct_zone_id(&conn->zone, conn->zone.dir) ==
> -				    nf_ct_zone_id(zone, zone->dir))
> +				    nf_ct_zone_id(&conn->zone,
> +						  nf_conncount_zone_dir(&conn->zone)) ==
> +				    nf_ct_zone_id(zone,
> +						  nf_conncount_zone_dir(zone)))

Should this be a simpler:

                                if (nf_ct_tuple_equal(&conn->tuple, &tuple) &&
-                                   nf_ct_zone_id(&conn->zone, conn->zone.dir) ==
-                                   nf_ct_zone_id(zone, zone->dir))
+                                   nf_ct_zone_equal(&conn->zone, &zone), IP_CT_DIR_ORIGINAL)

?

The tuple is always the 'original' direction, so it would follow that
we should not care about reply zone dir.

Also see:
https://sashiko.dev/#/patchset/20260706114820.74006-1-zhaoyz24%40mails.tsinghua.edu.cn


  reply	other threads:[~2026-07-07 14:58 UTC|newest]

Thread overview: 3+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2026-07-06 11:48 [PATCH nf] netfilter: nf_conncount: fix zone comparison in tuple dedup Yizhou Zhao
2026-07-07 14:58 ` Florian Westphal [this message]
2026-07-08  5:30   ` Yizhou Zhao

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=ak0UDVc4gZbfzrtM@strlen.de \
    --to=fw@strlen.de \
    --cc=coreteam@netfilter.org \
    --cc=davem@davemloft.net \
    --cc=edumazet@google.com \
    --cc=fengxw06@126.com \
    --cc=horms@kernel.org \
    --cc=kuba@kernel.org \
    --cc=linux-kernel@vger.kernel.org \
    --cc=netdev@vger.kernel.org \
    --cc=netfilter-devel@vger.kernel.org \
    --cc=pabeni@redhat.com \
    --cc=pablo@netfilter.org \
    --cc=phil@nwl.cc \
    --cc=qli01@tsinghua.edu.cn \
    --cc=stable@vger.kernel.org \
    --cc=wangao@seu.edu.cn \
    --cc=xuke@tsinghua.edu.cn \
    --cc=yangyx22@mails.tsinghua.edu.cn \
    --cc=zhaoyz24@mails.tsinghua.edu.cn \
    /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