Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1755474Ab0KJS32 (ORCPT ); Wed, 10 Nov 2010 13:29:28 -0500 Received: from mail-ew0-f46.google.com ([209.85.215.46]:41399 "EHLO mail-ew0-f46.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1754148Ab0KJS31 (ORCPT ); Wed, 10 Nov 2010 13:29:27 -0500 DomainKey-Signature: a=rsa-sha1; c=nofws; d=gmail.com; s=gamma; h=from:to:cc:subject:date:message-id:x-mailer; b=tq/ib5g152i4fYelzMQYIvMn6wzGPYLaIzVOP9rlk4s8ieQrdYS39+fEge9xetAPFZ CXTM72fpAx7l5vOxXIVW6aryBzFGjxddl+6WPM1Oqw8PXH3OFsVnB0NPlWfatdTCHVpI J4+gQ8PsOIMFhdDQrBG5F0mEEKoSukUQuYjMs= From: Vasiliy Kulikov To: kernel-janitors@vger.kernel.org Cc: "David S. Miller" , Jiri Pirko , Eric Dumazet , netdev@vger.kernel.org, linux-kernel@vger.kernel.org Subject: [PATCH 2/3 RESEND] net: packet: fix information leak to userland Date: Wed, 10 Nov 2010 21:29:18 +0300 Message-Id: <1289413760-12510-1-git-send-email-segooon@gmail.com> X-Mailer: git-send-email 1.7.0.4 Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 1600 Lines: 44 packet_getname_spkt() doesn't initialize all members of sa_data field of sockaddr struct if strlen(dev->name) < 13. This structure is then copied to userland. It leads to leaking of contents of kernel stack memory. We have to fully fill sa_data with strncpy() instead of strlcpy(). The same with packet_getname(): it doesn't initialize sll_pkttype field of sockaddr_ll. Set it to zero. Signed-off-by: Vasiliy Kulikov --- Compile tested. net/packet/af_packet.c | 3 ++- 1 files changed, 2 insertions(+), 1 deletions(-) diff --git a/net/packet/af_packet.c b/net/packet/af_packet.c index 3616f27..0856a13 100644 --- a/net/packet/af_packet.c +++ b/net/packet/af_packet.c @@ -1719,7 +1719,7 @@ static int packet_getname_spkt(struct socket *sock, struct sockaddr *uaddr, rcu_read_lock(); dev = dev_get_by_index_rcu(sock_net(sk), pkt_sk(sk)->ifindex); if (dev) - strlcpy(uaddr->sa_data, dev->name, 15); + strncpy(uaddr->sa_data, dev->name, 14); else memset(uaddr->sa_data, 0, 14); rcu_read_unlock(); @@ -1742,6 +1742,7 @@ static int packet_getname(struct socket *sock, struct sockaddr *uaddr, sll->sll_family = AF_PACKET; sll->sll_ifindex = po->ifindex; sll->sll_protocol = po->num; + sll->sll_pkttype = 0; rcu_read_lock(); dev = dev_get_by_index_rcu(sock_net(sk), po->ifindex); if (dev) { -- 1.7.0.4 -- 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/