From patchwork Mon Mar 11 12:32:19 2013 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 8bit X-Patchwork-Submitter: Luis Henriques X-Patchwork-Id: 226557 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 C124B2C02BC for ; Mon, 11 Mar 2013 23:32:31 +1100 (EST) Received: from localhost ([127.0.0.1] helo=huckleberry.canonical.com) by huckleberry.canonical.com with esmtp (Exim 4.76) (envelope-from ) id 1UF1tv-0004Gu-2a; Mon, 11 Mar 2013 12:32:23 +0000 Received: from youngberry.canonical.com ([91.189.89.112]) by huckleberry.canonical.com with esmtp (Exim 4.76) (envelope-from ) id 1UF1ts-0004GZ-SX for kernel-team@lists.ubuntu.com; Mon, 11 Mar 2013 12:32:20 +0000 Received: from bl15-242-192.dsl.telepac.pt ([188.80.242.192] helo=localhost) by youngberry.canonical.com with esmtpsa (TLS1.0:DHE_RSA_AES_128_CBC_SHA1:16) (Exim 4.71) (envelope-from ) id 1UF1ts-0003gm-Lx for kernel-team@lists.ubuntu.com; Mon, 11 Mar 2013 12:32:20 +0000 From: Luis Henriques To: kernel-team@lists.ubuntu.com Subject: [PATCH] net/sctp: Validate parameter size for SCTP_GET_ASSOC_STATS Date: Mon, 11 Mar 2013 12:32:19 +0000 Message-Id: <1363005139-4420-1-git-send-email-luis.henriques@canonical.com> X-Mailer: git-send-email 1.8.1.2 MIME-Version: 1.0 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: , Errors-To: kernel-team-bounces@lists.ubuntu.com Sender: kernel-team-bounces@lists.ubuntu.com From: Guenter Roeck CVE-2013-1828 BugLink: http://bugs.launchpad.net/bugs/1152791 Building sctp may fail with: In function ‘copy_from_user’, inlined from ‘sctp_getsockopt_assoc_stats’ at net/sctp/socket.c:5656:20: arch/x86/include/asm/uaccess_32.h:211:26: error: call to ‘copy_from_user_overflow’ declared with attribute error: copy_from_user() buffer size is not provably correct if built with W=1 due to a missing parameter size validation before the call to copy_from_user. Signed-off-by: Guenter Roeck Acked-by: Vlad Yasevich Signed-off-by: David S. Miller (cherry picked from commit 726bc6b092da4c093eb74d13c07184b18c1af0f1) Signed-off-by: Luis Henriques --- net/sctp/socket.c | 6 +++--- 1 file changed, 3 insertions(+), 3 deletions(-) diff --git a/net/sctp/socket.c b/net/sctp/socket.c index cedd9bf..9ef5c73 100644 --- a/net/sctp/socket.c +++ b/net/sctp/socket.c @@ -5653,6 +5653,9 @@ static int sctp_getsockopt_assoc_stats(struct sock *sk, int len, if (len < sizeof(sctp_assoc_t)) return -EINVAL; + /* Allow the struct to grow and fill in as much as possible */ + len = min_t(size_t, len, sizeof(sas)); + if (copy_from_user(&sas, optval, len)) return -EFAULT; @@ -5686,9 +5689,6 @@ static int sctp_getsockopt_assoc_stats(struct sock *sk, int len, /* Mark beginning of a new observation period */ asoc->stats.max_obs_rto = asoc->rto_min; - /* Allow the struct to grow and fill in as much as possible */ - len = min_t(size_t, len, sizeof(sas)); - if (put_user(len, optlen)) return -EFAULT;