From patchwork Wed Jul 15 09:10:11 2015 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Luis Henriques X-Patchwork-Id: 495548 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 9260A1402B1; Wed, 15 Jul 2015 19:13:49 +1000 (AEST) Received: from localhost ([127.0.0.1] helo=huckleberry.canonical.com) by huckleberry.canonical.com with esmtp (Exim 4.76) (envelope-from ) id 1ZFIl7-0005tB-Dx; Wed, 15 Jul 2015 09:13:45 +0000 Received: from youngberry.canonical.com ([91.189.89.112]) by huckleberry.canonical.com with esmtp (Exim 4.76) (envelope-from ) id 1ZFIkh-0005Vl-Uu for kernel-team@lists.ubuntu.com; Wed, 15 Jul 2015 09:13:19 +0000 Received: from av-217-129-142-138.netvisao.pt ([217.129.142.138] helo=localhost) by youngberry.canonical.com with esmtpsa (TLS1.0:RSA_AES_128_CBC_SHA1:16) (Exim 4.76) (envelope-from ) id 1ZFIkh-0007JM-Ia; Wed, 15 Jul 2015 09:13:19 +0000 From: Luis Henriques To: linux-kernel@vger.kernel.org, stable@vger.kernel.org, kernel-team@lists.ubuntu.com Subject: [PATCH 3.16.y-ckt 016/185] [media] cx24116: fix a buffer overflow when checking userspace params Date: Wed, 15 Jul 2015 10:10:11 +0100 Message-Id: <1436951580-15977-17-git-send-email-luis.henriques@canonical.com> X-Mailer: git-send-email 2.1.4 In-Reply-To: <1436951580-15977-1-git-send-email-luis.henriques@canonical.com> References: <1436951580-15977-1-git-send-email-luis.henriques@canonical.com> X-Extended-Stable: 3.16 Cc: Mauro Carvalho Chehab 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 3.16.7-ckt15 -stable review patch. If anyone has any objections, please let me know. ------------------ From: Mauro Carvalho Chehab commit 1fa2337a315a2448c5434f41e00d56b01a22283c upstream. The maximum size for a DiSEqC command is 6, according to the userspace API. However, the code allows to write up much more values: drivers/media/dvb-frontends/cx24116.c:983 cx24116_send_diseqc_msg() error: buffer overflow 'd->msg' 6 <= 23 Signed-off-by: Mauro Carvalho Chehab Signed-off-by: Luis Henriques --- drivers/media/dvb-frontends/cx24116.c | 8 ++++---- 1 file changed, 4 insertions(+), 4 deletions(-) diff --git a/drivers/media/dvb-frontends/cx24116.c b/drivers/media/dvb-frontends/cx24116.c index 2916d7c74a1d..7bc68b355c0b 100644 --- a/drivers/media/dvb-frontends/cx24116.c +++ b/drivers/media/dvb-frontends/cx24116.c @@ -963,6 +963,10 @@ static int cx24116_send_diseqc_msg(struct dvb_frontend *fe, struct cx24116_state *state = fe->demodulator_priv; int i, ret; + /* Validate length */ + if (d->msg_len > sizeof(d->msg)) + return -EINVAL; + /* Dump DiSEqC message */ if (debug) { printk(KERN_INFO "cx24116: %s(", __func__); @@ -974,10 +978,6 @@ static int cx24116_send_diseqc_msg(struct dvb_frontend *fe, printk(") toneburst=%d\n", toneburst); } - /* Validate length */ - if (d->msg_len > (CX24116_ARGLEN - CX24116_DISEQC_MSGOFS)) - return -EINVAL; - /* DiSEqC message */ for (i = 0; i < d->msg_len; i++) state->dsec_cmd.args[CX24116_DISEQC_MSGOFS + i] = d->msg[i];