From patchwork Fri Jun 28 18:51:49 2013 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Kamal Mostafa X-Patchwork-Id: 255617 Return-Path: X-Original-To: incoming@patchwork.ozlabs.org Delivered-To: patchwork-incoming@bilbo.ozlabs.org Received: from huckleberry.canonical.com (huckleberry.canonical.com [91.189.94.19]) by ozlabs.org (Postfix) with ESMTP id 365B92C0090 for ; Sat, 29 Jun 2013 04:59:15 +1000 (EST) Received: from localhost ([127.0.0.1] helo=huckleberry.canonical.com) by huckleberry.canonical.com with esmtp (Exim 4.76) (envelope-from ) id 1Usdsz-0006uu-F3; Fri, 28 Jun 2013 18:59:09 +0000 Received: from youngberry.canonical.com ([91.189.89.112]) by huckleberry.canonical.com with esmtp (Exim 4.76) (envelope-from ) id 1Usds6-0006QX-CX for kernel-team@lists.ubuntu.com; Fri, 28 Jun 2013 18:58:14 +0000 Received: from c-67-160-231-42.hsd1.ca.comcast.net ([67.160.231.42] helo=fourier) by youngberry.canonical.com with esmtpsa (TLS1.0:DHE_RSA_AES_128_CBC_SHA1:16) (Exim 4.71) (envelope-from ) id 1UsdmY-0007ab-Vp; Fri, 28 Jun 2013 18:52:31 +0000 Received: from kamal by fourier with local (Exim 4.80) (envelope-from ) id 1UsdmW-0006am-R4; Fri, 28 Jun 2013 11:52:28 -0700 From: Kamal Mostafa To: linux-kernel@vger.kernel.org, stable@vger.kernel.org, kernel-team@lists.ubuntu.com Subject: [PATCH 087/105] packet: packet_getname_spkt: make sure string is always 0-terminated Date: Fri, 28 Jun 2013 11:51:49 -0700 Message-Id: <1372445527-24414-88-git-send-email-kamal@canonical.com> X-Mailer: git-send-email 1.8.1.2 In-Reply-To: <1372445527-24414-1-git-send-email-kamal@canonical.com> References: <1372445527-24414-1-git-send-email-kamal@canonical.com> X-Extended-Stable: 3.8 Cc: Kamal Mostafa , Daniel Borkmann , "David S. Miller" X-BeenThere: kernel-team@lists.ubuntu.com X-Mailman-Version: 2.1.14 Precedence: list List-Id: Kernel team discussions List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , MIME-Version: 1.0 Errors-To: kernel-team-bounces@lists.ubuntu.com Sender: kernel-team-bounces@lists.ubuntu.com 3.8.13.4 -stable review patch. If anyone has any objections, please let me know. ------------------ From: Daniel Borkmann [ Upstream commit 2dc85bf323515e59e15dfa858d1472bb25cad0fe ] 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: Kamal Mostafa --- 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 d376545..dbddeb4 100644 --- a/net/packet/af_packet.c +++ b/net/packet/af_packet.c @@ -2769,12 +2769,11 @@ 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);