From patchwork Mon Jan 31 10:56:14 2022 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Greg KH X-Patchwork-Id: 538878 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by smtp.lore.kernel.org (Postfix) with ESMTP id 929AFC433F5 for ; Mon, 31 Jan 2022 11:05:01 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1358831AbiAaLFA (ORCPT ); Mon, 31 Jan 2022 06:05:00 -0500 Received: from ams.source.kernel.org ([145.40.68.75]:51878 "EHLO ams.source.kernel.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1358846AbiAaLD4 (ORCPT ); Mon, 31 Jan 2022 06:03:56 -0500 Received: from smtp.kernel.org (relay.kernel.org [52.25.139.140]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by ams.source.kernel.org (Postfix) with ESMTPS id A2B9EB82A31; Mon, 31 Jan 2022 11:03:53 +0000 (UTC) Received: by smtp.kernel.org (Postfix) with ESMTPSA id 2780AC340E8; Mon, 31 Jan 2022 11:03:51 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=linuxfoundation.org; s=korg; t=1643627032; bh=kz2Lt6zhXS8sxBsfLdzg8w/oWhJ3AggNaq9bxEXj+Cw=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=Vkyi+OQa5agEqtFxYK6408gzreHIzC2Xt4RcZO46+UDaG7ZaGibl4wFAP00dKVnNg 7hspbhmG/HLS7EzGkjjDs7QDj5Y+XtQ6XYQqBA54x33GtQmGhQvb/6X0RcfLSZqCID WrEtXTZM7MCw2S1NEp0FjP2NmHctOZ8cIFJr5jtI= From: Greg Kroah-Hartman To: linux-kernel@vger.kernel.org Cc: Greg Kroah-Hartman , stable@vger.kernel.org, Congyu Liu , "David S. Miller" , Sasha Levin Subject: [PATCH 5.10 053/100] net: fix information leakage in /proc/net/ptype Date: Mon, 31 Jan 2022 11:56:14 +0100 Message-Id: <20220131105222.221575774@linuxfoundation.org> X-Mailer: git-send-email 2.35.1 In-Reply-To: <20220131105220.424085452@linuxfoundation.org> References: <20220131105220.424085452@linuxfoundation.org> User-Agent: quilt/0.66 MIME-Version: 1.0 Precedence: bulk List-ID: X-Mailing-List: stable@vger.kernel.org From: Congyu Liu commit 47934e06b65637c88a762d9c98329ae6e3238888 upstream. In one net namespace, after creating a packet socket without binding it to a device, users in other net namespaces can observe the new `packet_type` added by this packet socket by reading `/proc/net/ptype` file. This is minor information leakage as packet socket is namespace aware. Add a net pointer in `packet_type` to keep the net namespace of of corresponding packet socket. In `ptype_seq_show`, this net pointer must be checked when it is not NULL. Fixes: 2feb27dbe00c ("[NETNS]: Minor information leak via /proc/net/ptype file.") Signed-off-by: Congyu Liu Signed-off-by: David S. Miller Signed-off-by: Greg Kroah-Hartman Signed-off-by: Sasha Levin --- include/linux/netdevice.h | 1 + net/core/net-procfs.c | 3 ++- net/packet/af_packet.c | 2 ++ 3 files changed, 5 insertions(+), 1 deletion(-) --- a/include/linux/netdevice.h +++ b/include/linux/netdevice.h @@ -2543,6 +2543,7 @@ struct packet_type { struct net_device *); bool (*id_match)(struct packet_type *ptype, struct sock *sk); + struct net *af_packet_net; void *af_packet_priv; struct list_head list; }; --- a/net/core/net-procfs.c +++ b/net/core/net-procfs.c @@ -263,7 +263,8 @@ static int ptype_seq_show(struct seq_fil if (v == SEQ_START_TOKEN) seq_puts(seq, "Type Device Function\n"); - else if (pt->dev == NULL || dev_net(pt->dev) == seq_file_net(seq)) { + else if ((!pt->af_packet_net || net_eq(pt->af_packet_net, seq_file_net(seq))) && + (!pt->dev || net_eq(dev_net(pt->dev), seq_file_net(seq)))) { if (pt->type == htons(ETH_P_ALL)) seq_puts(seq, "ALL "); else --- a/net/packet/af_packet.c +++ b/net/packet/af_packet.c @@ -1735,6 +1735,7 @@ static int fanout_add(struct sock *sk, s match->prot_hook.dev = po->prot_hook.dev; match->prot_hook.func = packet_rcv_fanout; match->prot_hook.af_packet_priv = match; + match->prot_hook.af_packet_net = read_pnet(&match->net); match->prot_hook.id_match = match_fanout_group; match->max_num_members = args->max_num_members; list_add(&match->list, &fanout_list); @@ -3323,6 +3324,7 @@ static int packet_create(struct net *net po->prot_hook.func = packet_rcv_spkt; po->prot_hook.af_packet_priv = sk; + po->prot_hook.af_packet_net = sock_net(sk); if (proto) { po->prot_hook.type = proto;