From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from Chamillionaire.breakpoint.cc (Chamillionaire.breakpoint.cc [91.216.245.30]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by smtp.subspace.kernel.org (Postfix) with ESMTPS id 6C1D6395AF2; Fri, 10 Jul 2026 14:38:01 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=91.216.245.30 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1783694282; cv=none; b=WFHKFuCxHiffIsNwUJFMtELtdkpXGSXJ/Xt4+lNbGN7WXo91PZiSatVNPwSfAVdqPOJNwgTjkagOznU4seGBz35+hksYUeK66KWgI0cKIP/uNvvsaiQqCjaVcm6ipJbPqNna+umFv3MovnlTUzUeB4mACOxfvAKfF9iEW76iGeE= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1783694282; c=relaxed/simple; bh=ho6b7UqYZeTzSjEoLdR9pW2HnXH+Fkv44alSVEd03ak=; h=From:To:Cc:Subject:Date:Message-ID:In-Reply-To:References: MIME-Version; b=YHCWxLvvpCh7aGFa5M241HvOp/swjwE7IXgM88QVmsiSPRkFzwtD0CRLnIuCPLMD5Og5tLajon3GTMZ6SfBVb7wuBqKfcu5/k1Po4oUyzA0nxv0/9/L7nsntVq4vSqr1ZsBFVX5JCA/GngOGaspe2dXgRk2mYzt6Xm9jqsR/ITc= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dmarc=none (p=none dis=none) header.from=strlen.de; spf=pass smtp.mailfrom=Chamillionaire.breakpoint.cc; arc=none smtp.client-ip=91.216.245.30 Authentication-Results: smtp.subspace.kernel.org; dmarc=none (p=none dis=none) header.from=strlen.de Authentication-Results: smtp.subspace.kernel.org; spf=pass smtp.mailfrom=Chamillionaire.breakpoint.cc Received: by Chamillionaire.breakpoint.cc (Postfix, from userid 1003) id D625160503; Fri, 10 Jul 2026 16:37:59 +0200 (CEST) From: Florian Westphal To: Cc: Paolo Abeni , "David S. Miller" , Eric Dumazet , Jakub Kicinski , , pablo@netfilter.org Subject: [PATCH net 4/9] netfilter: nf_conncount: fix zone comparison in tuple dedup Date: Fri, 10 Jul 2026 16:37:28 +0200 Message-ID: <20260710143733.29741-5-fw@strlen.de> X-Mailer: git-send-email 2.54.0 In-Reply-To: <20260710143733.29741-1-fw@strlen.de> References: <20260710143733.29741-1-fw@strlen.de> Precedence: bulk X-Mailing-List: netfilter-devel@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-Transfer-Encoding: 8bit From: Yizhou Zhao 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. Those helpers take enum ip_conntrack_dir values: IP_CT_DIR_ORIGINAL is 0 and IP_CT_DIR_REPLY is 1. However, zone->dir is a u8 bitmask: NF_CT_ZONE_DIR_ORIG is 1, NF_CT_ZONE_DIR_REPL is 2 and NF_CT_DEFAULT_ZONE_DIR is 3. Passing that bitmask as the enum direction shifts the meaning of every non-zero value. An ORIG-only zone passes 1 and is tested as REPLY, while REPL-only and default zones pass 2 or 3 and test bits beyond the valid direction range. In those cases nf_ct_zone_id() can fall back to NF_CT_DEFAULT_ZONE_ID instead of using the real zone id, so different zones can be treated as equal and dedup collapses to tuple equality alone. nf_conncount stores and compares the original-direction tuple for a connection. If an skb already has an attached conntrack entry, get_ct_or_tuple_from_skb() explicitly copies ct->tuplehash[IP_CT_DIR_ORIGINAL].tuple, regardless of the packet's ctinfo. Therefore the zone comparison in the tuple dedup path must use IP_CT_DIR_ORIGINAL as well; the zone direction bitmask describes where a zone id applies, not which direction this conncount tuple represents. Fix the two dedup comparisons by passing IP_CT_DIR_ORIGINAL directly. Do not special-case NF_CT_DEFAULT_ZONE_DIR and do not compare raw zone ids: using the existing helpers with IP_CT_DIR_ORIGINAL preserves the direction-aware NF_CT_DEFAULT_ZONE_ID fallback. A default bidirectional zone contains the ORIG bit, so it naturally returns the real zone id; reply-only zones continue to fall back for original-direction tuple comparisons. Fixes: 21ba8847f857 ("netfilter: nf_conncount: Fix garbage collection with zones") Fixes: b36e4523d4d5 ("netfilter: nf_conncount: fix garbage collection confirm race") Cc: stable@vger.kernel.org Reported-by: Yizhou Zhao Reported-by: Yuxiang Yang Reported-by: Ao Wang Reported-by: Xuewei Feng Reported-by: Qi Li Reported-by: Ke Xu Assisted-by: Claude-Code:GLM-5.2 Signed-off-by: Yizhou Zhao Signed-off-by: Florian Westphal --- net/netfilter/nf_conncount.c | 6 +++--- 1 file changed, 3 insertions(+), 3 deletions(-) diff --git a/net/netfilter/nf_conncount.c b/net/netfilter/nf_conncount.c index 91582069f6d2..e9ea6d9466e7 100644 --- a/net/netfilter/nf_conncount.c +++ b/net/netfilter/nf_conncount.c @@ -211,8 +211,8 @@ 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, IP_CT_DIR_ORIGINAL) == + nf_ct_zone_id(zone, IP_CT_DIR_ORIGINAL)) goto out_put; /* already exists */ } else { collect++; @@ -223,7 +223,7 @@ static int __nf_conncount_add(struct net *net, found_ct = nf_ct_tuplehash_to_ctrack(found); if (nf_ct_tuple_equal(&conn->tuple, &tuple) && - nf_ct_zone_equal(found_ct, zone, zone->dir)) { + nf_ct_zone_equal(found_ct, zone, IP_CT_DIR_ORIGINAL)) { /* * We should not see tuples twice unless someone hooks * this into a table without "-p tcp --syn". -- 2.54.0