From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1755305Ab3GBLIX (ORCPT ); Tue, 2 Jul 2013 07:08:23 -0400 Received: from youngberry.canonical.com ([91.189.89.112]:36237 "EHLO youngberry.canonical.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1755056Ab3GBLIQ (ORCPT ); Tue, 2 Jul 2013 07:08:16 -0400 From: Luis Henriques To: linux-kernel@vger.kernel.org, stable@vger.kernel.org, kernel-team@lists.ubuntu.com Cc: Daniel Borkmann , "David S. Miller" , Luis Henriques Subject: [PATCH 21/50] packet: packet_getname_spkt: make sure string is always 0-terminated Date: Tue, 2 Jul 2013 12:07:09 +0100 Message-Id: <1372763258-20664-22-git-send-email-luis.henriques@canonical.com> X-Mailer: git-send-email 1.8.1.2 In-Reply-To: <1372763258-20664-1-git-send-email-luis.henriques@canonical.com> References: <1372763258-20664-1-git-send-email-luis.henriques@canonical.com> X-Extended-Stable: 3.5 Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org 3.5.7.16 -stable review patch. If anyone has any objections, please let me know. ------------------ From: Daniel Borkmann commit 2dc85bf323515e59e15dfa858d1472bb25cad0fe upstream. uaddr->sa_data is exactly of size 14, which is hard-coded here and passed as a size argument to strncpy(). A device name can be of size IFNAMSIZ (== 16), meaning we might leave the destination string unterminated. Thus, use strlcpy() and also sizeof() while we're at it. We need to memset the data area beforehand, since strlcpy does not padd the remaining buffer with zeroes for user space, so that we do not possibly leak anything. Signed-off-by: Daniel Borkmann Signed-off-by: David S. Miller Signed-off-by: Luis Henriques --- net/packet/af_packet.c | 5 ++--- 1 file changed, 2 insertions(+), 3 deletions(-) diff --git a/net/packet/af_packet.c b/net/packet/af_packet.c index 4137d01..1522b93 100644 --- a/net/packet/af_packet.c +++ b/net/packet/af_packet.c @@ -2854,12 +2854,11 @@ static int packet_getname_spkt(struct socket *sock, struct sockaddr *uaddr, return -EOPNOTSUPP; uaddr->sa_family = AF_PACKET; + memset(uaddr->sa_data, 0, sizeof(uaddr->sa_data)); rcu_read_lock(); dev = dev_get_by_index_rcu(sock_net(sk), pkt_sk(sk)->ifindex); if (dev) - strncpy(uaddr->sa_data, dev->name, 14); - else - memset(uaddr->sa_data, 0, 14); + strlcpy(uaddr->sa_data, dev->name, sizeof(uaddr->sa_data)); rcu_read_unlock(); *uaddr_len = sizeof(*uaddr); -- 1.8.1.2