Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S965797Ab2EOCuO (ORCPT ); Mon, 14 May 2012 22:50:14 -0400 Received: from mail.windriver.com ([147.11.1.11]:49672 "EHLO mail.windriver.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S965136Ab2EOCRW (ORCPT ); Mon, 14 May 2012 22:17:22 -0400 From: Paul Gortmaker To: , Subject: [34-longterm 101/179] af_packet: prevent information leak Date: Mon, 14 May 2012 22:13:17 -0400 Message-ID: <1337048075-6132-102-git-send-email-paul.gortmaker@windriver.com> X-Mailer: git-send-email 1.7.9.6 In-Reply-To: <1337048075-6132-1-git-send-email-paul.gortmaker@windriver.com> References: <1337048075-6132-1-git-send-email-paul.gortmaker@windriver.com> MIME-Version: 1.0 Content-Type: text/plain Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 2374 Lines: 72 From: Eric Dumazet ------------------- This is a commit scheduled for the next v2.6.34 longterm release. http://git.kernel.org/?p=linux/kernel/git/paulg/longterm-queue-2.6.34.git If you see a problem with using this for longterm, please comment. ------------------- commit 13fcb7bd322164c67926ffe272846d4860196dc6 upstream. In 2.6.27, commit 393e52e33c6c2 (packet: deliver VLAN TCI to userspace) added a small information leak. Add padding field and make sure its zeroed before copy to user. Signed-off-by: Eric Dumazet CC: Patrick McHardy Signed-off-by: David S. Miller Signed-off-by: Paul Gortmaker --- include/linux/if_packet.h | 2 ++ net/packet/af_packet.c | 2 ++ 2 files changed, 4 insertions(+) diff --git a/include/linux/if_packet.h b/include/linux/if_packet.h index aa57a5f..9b8dc3a 100644 --- a/include/linux/if_packet.h +++ b/include/linux/if_packet.h @@ -60,6 +60,7 @@ struct tpacket_auxdata { __u16 tp_mac; __u16 tp_net; __u16 tp_vlan_tci; + __u16 tp_padding; }; /* Rx ring - header status */ @@ -98,6 +99,7 @@ struct tpacket2_hdr { __u32 tp_sec; __u32 tp_nsec; __u16 tp_vlan_tci; + __u16 tp_padding; }; #define TPACKET2_HDRLEN (TPACKET_ALIGN(sizeof(struct tpacket2_hdr)) + sizeof(struct sockaddr_ll)) diff --git a/net/packet/af_packet.c b/net/packet/af_packet.c index b1bc2d2..4096a66 100644 --- a/net/packet/af_packet.c +++ b/net/packet/af_packet.c @@ -751,6 +751,7 @@ static int tpacket_rcv(struct sk_buff *skb, struct net_device *dev, h.h2->tp_sec = ts.tv_sec; h.h2->tp_nsec = ts.tv_nsec; h.h2->tp_vlan_tci = vlan_tx_tag_get(skb); + h.h2->tp_padding = 0; hdrlen = sizeof(*h.h2); break; default: @@ -1617,6 +1618,7 @@ static int packet_recvmsg(struct kiocb *iocb, struct socket *sock, aux.tp_net = skb_network_offset(skb); aux.tp_vlan_tci = vlan_tx_tag_get(skb); + aux.tp_padding = 0; put_cmsg(msg, SOL_PACKET, PACKET_AUXDATA, sizeof(aux), &aux); } -- 1.7.9.6 -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/