Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S934795AbbHDPGf (ORCPT ); Tue, 4 Aug 2015 11:06:35 -0400 Received: from mx2.suse.de ([195.135.220.15]:58904 "EHLO mx2.suse.de" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1756704AbbHDOlf (ORCPT ); Tue, 4 Aug 2015 10:41:35 -0400 X-Amavis-Alert: BAD HEADER SECTION, Duplicate header field: "References" From: Jiri Slaby To: stable@vger.kernel.org Cc: linux-kernel@vger.kernel.org, Mauro Carvalho Chehab , Jiri Slaby Subject: [PATCH 3.12 053/123] cx24116: fix a buffer overflow when checking userspace params Date: Tue, 4 Aug 2015 16:39:57 +0200 Message-Id: <1cf4d96aed242aac53f0c7fe9cb9b792e95ea417.1438699154.git.jslaby@suse.cz> X-Mailer: git-send-email 2.5.0 In-Reply-To: References: In-Reply-To: References: Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 1829 Lines: 52 From: Mauro Carvalho Chehab 3.12-stable review patch. If anyone has any objections, please let me know. =============== 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: Jiri Slaby --- 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]; -- 2.5.0 -- 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/