From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from mail-pj1-f49.google.com (mail-pj1-f49.google.com [209.85.216.49]) (using TLSv1.2 with cipher ECDHE-RSA-AES128-GCM-SHA256 (128/128 bits)) (No client certificate requested) by smtp.subspace.kernel.org (Postfix) with ESMTPS id EAC8337F73E for ; Sun, 29 Mar 2026 16:52:27 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=209.85.216.49 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1774803149; cv=none; b=pbJq9VyhL5t7sWbuM0ebEXxL8heGXVtK9dUPydV710af3MEtGPHf5Nd9TpStZLqZY481yOFbuiDy+2TkQ2uAu3i3K0xWVI2NFe4qKvMnndu/Tl8aS7Vrb1oRVhg8hZF7IhDijbCVSfypIMGKZnOZQhEXXNAbj+znmfjRsujmoxk= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1774803149; c=relaxed/simple; bh=b2bwpUQRoHCr+Bn8QVQtUP36sssXWqkwyRequ+KE2dU=; h=From:To:Cc:Subject:Date:Message-ID:MIME-Version; b=luYOKPTTqNZ8i3A+eqRpXBujZ82aaz9Ui6CWaxlt4CFVxzGNZfiG7CHz8pG8PXWanJClhZ8GKkCQyvkiXvNMuNzsxOoI+F6gYq9xz4Q8D9tKmrmJ5ThM5fBTLCIeWAjYlVdnuE+TfuCnSpGVokbZOXDHS4vPh+BpgUxgtVwaFEE= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dmarc=pass (p=none dis=none) header.from=gmail.com; spf=pass smtp.mailfrom=gmail.com; dkim=pass (2048-bit key) header.d=gmail.com header.i=@gmail.com header.b=AmMljpc0; arc=none smtp.client-ip=209.85.216.49 Authentication-Results: smtp.subspace.kernel.org; dmarc=pass (p=none dis=none) header.from=gmail.com Authentication-Results: smtp.subspace.kernel.org; spf=pass smtp.mailfrom=gmail.com Authentication-Results: smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=gmail.com header.i=@gmail.com header.b="AmMljpc0" Received: by mail-pj1-f49.google.com with SMTP id 98e67ed59e1d1-35d96be7c13so816678a91.0 for ; Sun, 29 Mar 2026 09:52:27 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=gmail.com; s=20251104; t=1774803147; x=1775407947; darn=vger.kernel.org; h=content-transfer-encoding:mime-version:message-id:date:subject:cc :to:from:from:to:cc:subject:date:message-id:reply-to; bh=1/dtluh18hHrnfgX94Rzw61kxdR4s6K+3hZ7ZcF6n8c=; b=AmMljpc0Dv4XFB84YTntmrQkUY5mzH0/ux74qKHgKpvqvUVIj/aA028gnMWUNC4eIK e912tcIrIW4a1aWnVuNAoXN/ne6C1IWz7ooy5kGsy7VddvVWX3vXsulsTyJLI14p++PT euLypg215+g8Y2Ea+VnwLfndmQBpWSt3ASPrq/qDcqQODK7wvTvedO4bbcp7EbRsv79q nZWZbAfKpruXf+41bILJSKvqTqlJfU13J/2FyAZ32xok5iehEoNrHVynBNbxUPdjgBB0 TcmB3m5uNaFm05Kx0aIoPgir/DilTemFHyJLZ807N63wH1XzHgu/qq9fdsC5FPv616Ga XCkA== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20251104; t=1774803147; x=1775407947; h=content-transfer-encoding:mime-version:message-id:date:subject:cc :to:from:x-gm-gg:x-gm-message-state:from:to:cc:subject:date :message-id:reply-to; bh=1/dtluh18hHrnfgX94Rzw61kxdR4s6K+3hZ7ZcF6n8c=; b=At5u+CEm3dhHsNeCsCqqCY1QRt4qSX6BnhHhWHdN1ar+tTMDe+Nylmxs+KBHs1iPNI isAdnExtKdT46iNLQ3AimgAn5mdIaLzc3whVEc/XHBsUe41hrBiKyT/PQWcbD3Tpmr1E kZOkdMhyBQcJQuMcZQYtgW8LLt8B0H5O+oRudW/qhk1Vo2MNF3GvrlEjm+xV1CoIOYND 645C9k+VG4ZJiLPHHYI4IjufBjQxpTLTLyNmoX9dTJsYrnrNE5iv21xMbOsL+RDLFdsx iH0Vqk1L28rQsopNaSqOLspf2id//BNSFllQPvWAZDmbbQ2mjLNAZUDrBl8ey04uXQFo ccdw== X-Forwarded-Encrypted: i=1; AJvYcCWNIS3SXlwRzdZsacmgix+9vr5LlIDXOmIOQkk7LLKukAy7gaSpKbBHSdPRgbBNsa0wD642YH8=@vger.kernel.org X-Gm-Message-State: AOJu0YzbafNJol0C+KOV1WBQBsOu5OoBhZfGqdsEL0WQMhpKJ0wcD5Rt ctQg4U7W8qnkVQBzR9nZOBttNkrX+/5gt5bcYpCgrM7aLyKay7yXsUSn X-Gm-Gg: ATEYQzzrelbpwIP5yEBrIn6fJpgqfm3tvG3/TnlEjR0zH4XQZ4olmcT27E7KW7R/nEz yAiNFyygcpTAxu0d0S2ulnOOnJcl2DAWf/asoYlQou2/X9X8a0nD/CAFu0Wxp3cpCgrhwY1UpcZ QIeiIA8EFS8+xF6gq+TtssZYRUhbIobGSXl+x8TvLqPk3tW2Rk+F5LB/ITt9Jklwbl3aQaj+nkk kwaxVaFiJRqijSoy27PaqR/KLecILuF0YM13MRDk4M2J/8Rw9ZRUiH7AkGiIn5CXqrQM7b8bIWx yvGw+voqD0+JNIYBhI2IsdikQ43d7LEt4ebFtORYCaqIdbIN67gEOQ8rr++x7ABiFLuTMnMNZ+g a0OOaZU8ecdEZ474qrbqvF9BVnC+DdLvkhC8QJeQx3MWsOQ+gt2yQzniUH89atokErd2vuQyfN5 qGLgFiBU3o08C4FzKd2NhgbPRH3tgJGk20hWk= X-Received: by 2002:a17:90a:1108:b0:35d:9276:eba7 with SMTP id 98e67ed59e1d1-35d9276f7b1mr3183202a91.7.1774803147220; Sun, 29 Mar 2026 09:52:27 -0700 (PDT) Received: from localhost.localdomain ([47.236.127.140]) by smtp.gmail.com with ESMTPSA id 98e67ed59e1d1-35c22b9fc96sm9854141a91.7.2026.03.29.09.52.23 (version=TLS1_3 cipher=TLS_AES_256_GCM_SHA384 bits=256/256); Sun, 29 Mar 2026 09:52:25 -0700 (PDT) From: Qi Tang To: Pablo Neira Ayuso , Florian Westphal Cc: Phil Sutter , netfilter-devel@vger.kernel.org, coreteam@netfilter.org, netdev@vger.kernel.org, Qi Tang Subject: [PATCH] netfilter: ctnetlink: zero expect NAT fields when CTA_EXPECT_NAT absent Date: Mon, 30 Mar 2026 00:52:17 +0800 Message-ID: <20260329165217.241038-1-tpluszz77@gmail.com> X-Mailer: git-send-email 2.43.0 Precedence: bulk X-Mailing-List: netdev@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-Transfer-Encoding: 8bit ctnetlink_alloc_expect() allocates expectations from a non-zeroing slab cache via nf_ct_expect_alloc(). When CTA_EXPECT_NAT is not present in the netlink message, saved_addr and saved_proto are never initialized. Stale data from a previous slab occupant can then be dumped to userspace by ctnetlink_exp_dump_expect(), which checks these fields to decide whether to emit CTA_EXPECT_NAT. The safe sibling nf_ct_expect_init(), used by the packet path, explicitly zeroes these fields. Zero saved_addr and saved_proto in the else branch so that expectations created without NAT metadata cannot leak kernel heap contents to userspace. Confirmed by priming the expect slab with NAT-bearing expectations, freeing them, creating a new expectation without CTA_EXPECT_NAT, and observing that the ctnetlink dump emits a spurious CTA_EXPECT_NAT containing stale data from the prior allocation. Fixes: 076a0ca02644 ("netfilter: ctnetlink: add NAT support for expectations") Signed-off-by: Qi Tang --- net/netfilter/nf_conntrack_netlink.c | 4 ++++ 1 file changed, 4 insertions(+) diff --git a/net/netfilter/nf_conntrack_netlink.c b/net/netfilter/nf_conntrack_netlink.c index c57c665363e0..c152079f5ac7 100644 --- a/net/netfilter/nf_conntrack_netlink.c +++ b/net/netfilter/nf_conntrack_netlink.c @@ -3593,6 +3593,10 @@ ctnetlink_alloc_expect(const struct nlattr * const cda[], struct nf_conn *ct, exp, nf_ct_l3num(ct)); if (err < 0) goto err_out; + } else { + memset(&exp->saved_addr, 0, sizeof(exp->saved_addr)); + memset(&exp->saved_proto, 0, sizeof(exp->saved_proto)); + exp->dir = 0; } return exp; err_out: -- 2.43.0