From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1032934Ab2I1V5l (ORCPT ); Fri, 28 Sep 2012 17:57:41 -0400 Received: from mail-pb0-f46.google.com ([209.85.160.46]:34785 "EHLO mail-pb0-f46.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1031713Ab2I1UW3 (ORCPT ); Fri, 28 Sep 2012 16:22:29 -0400 From: Greg Kroah-Hartman To: linux-kernel@vger.kernel.org, stable@vger.kernel.org Cc: Greg Kroah-Hartman , alan@lxorguk.ukuu.org.uk, Mathias Krause , Gerrit Renker , "David S. Miller" Subject: [ 019/218] dccp: fix info leak via getsockopt(DCCP_SOCKOPT_CCID_TX_INFO) Date: Fri, 28 Sep 2012 13:13:56 -0700 Message-Id: <20120928201503.537526849@linuxfoundation.org> X-Mailer: git-send-email 1.7.12.1.428.g652398a In-Reply-To: <20120928201501.208384923@linuxfoundation.org> References: <20120928201501.208384923@linuxfoundation.org> User-Agent: quilt/0.60-2.1.2 Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org 3.4-stable review patch. If anyone has any objections, please let me know. ------------------ From: Mathias Krause [ Upstream commit 7b07f8eb75aa3097cdfd4f6eac3da49db787381d ] The CCID3 code fails to initialize the trailing padding bytes of struct tfrc_tx_info added for alignment on 64 bit architectures. It that for potentially leaks four bytes kernel stack via the getsockopt() syscall. Add an explicit memset(0) before filling the structure to avoid the info leak. Signed-off-by: Mathias Krause Cc: Gerrit Renker Signed-off-by: David S. Miller Signed-off-by: Greg Kroah-Hartman --- net/dccp/ccids/ccid3.c | 1 + 1 file changed, 1 insertion(+) --- a/net/dccp/ccids/ccid3.c +++ b/net/dccp/ccids/ccid3.c @@ -531,6 +531,7 @@ static int ccid3_hc_tx_getsockopt(struct case DCCP_SOCKOPT_CCID_TX_INFO: if (len < sizeof(tfrc)) return -EINVAL; + memset(&tfrc, 0, sizeof(tfrc)); tfrc.tfrctx_x = hc->tx_x; tfrc.tfrctx_x_recv = hc->tx_x_recv; tfrc.tfrctx_x_calc = hc->tx_x_calc;