From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1161711Ab3LFNDT (ORCPT ); Fri, 6 Dec 2013 08:03:19 -0500 Received: from youngberry.canonical.com ([91.189.89.112]:44356 "EHLO youngberry.canonical.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1758243Ab3LFNDQ (ORCPT ); Fri, 6 Dec 2013 08:03:16 -0500 From: Luis Henriques To: linux-kernel@vger.kernel.org, stable@vger.kernel.org, kernel-team@lists.ubuntu.com Cc: Mauro Carvalho Chehab , Luis Henriques Subject: [PATCH 3.11 168/272] [media] cxusb: Don't use dynamic static allocation Date: Fri, 6 Dec 2013 12:57:37 +0000 Message-Id: <1386334761-25517-169-git-send-email-luis.henriques@canonical.com> X-Mailer: git-send-email 1.8.3.2 In-Reply-To: <1386334761-25517-1-git-send-email-luis.henriques@canonical.com> References: <1386334761-25517-1-git-send-email-luis.henriques@canonical.com> X-Extended-Stable: 3.11 Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org 3.11.10.1 -stable review patch. If anyone has any objections, please let me know. ------------------ From: Mauro Carvalho Chehab commit 64f7ef8afbf89f3c72c4d2472e4914ca198c0668 upstream. Dynamic static allocation is evil, as Kernel stack is too low, and compilation complains about it on some archs: drivers/media/usb/dvb-usb/cxusb.c:209:1: warning: 'cxusb_i2c_xfer' uses dynamic stack allocation [enabled by default] drivers/media/usb/dvb-usb/cxusb.c:69:1: warning: 'cxusb_ctrl_msg' uses dynamic stack allocation [enabled by default] Instead, let's enforce a limit for the buffer to be the max size of a control URB payload data (64 bytes). Signed-off-by: Mauro Carvalho Chehab Reviewed-by: Hans Verkuil Signed-off-by: Mauro Carvalho Chehab Signed-off-by: Luis Henriques --- drivers/media/usb/dvb-usb/cxusb.c | 41 +++++++++++++++++++++++++++++++++++---- 1 file changed, 37 insertions(+), 4 deletions(-) diff --git a/drivers/media/usb/dvb-usb/cxusb.c b/drivers/media/usb/dvb-usb/cxusb.c index 3940bb0..20e345d 100644 --- a/drivers/media/usb/dvb-usb/cxusb.c +++ b/drivers/media/usb/dvb-usb/cxusb.c @@ -43,6 +43,9 @@ #include "lgs8gxx.h" #include "atbm8830.h" +/* Max transfer size done by I2C transfer functions */ +#define MAX_XFER_SIZE 64 + /* debug */ static int dvb_usb_cxusb_debug; module_param_named(debug, dvb_usb_cxusb_debug, int, 0644); @@ -57,7 +60,14 @@ static int cxusb_ctrl_msg(struct dvb_usb_device *d, u8 cmd, u8 *wbuf, int wlen, u8 *rbuf, int rlen) { int wo = (rbuf == NULL || rlen == 0); /* write-only */ - u8 sndbuf[1+wlen]; + u8 sndbuf[MAX_XFER_SIZE]; + + if (1 + wlen > sizeof(sndbuf)) { + warn("i2c wr: len=%d is too big!\n", + wlen); + return -EOPNOTSUPP; + } + memset(sndbuf, 0, 1+wlen); sndbuf[0] = cmd; @@ -158,7 +168,13 @@ static int cxusb_i2c_xfer(struct i2c_adapter *adap, struct i2c_msg msg[], if (msg[i].flags & I2C_M_RD) { /* read only */ - u8 obuf[3], ibuf[1+msg[i].len]; + u8 obuf[3], ibuf[MAX_XFER_SIZE]; + + if (1 + msg[i].len > sizeof(ibuf)) { + warn("i2c rd: len=%d is too big!\n", + msg[i].len); + return -EOPNOTSUPP; + } obuf[0] = 0; obuf[1] = msg[i].len; obuf[2] = msg[i].addr; @@ -172,7 +188,18 @@ static int cxusb_i2c_xfer(struct i2c_adapter *adap, struct i2c_msg msg[], } else if (i+1 < num && (msg[i+1].flags & I2C_M_RD) && msg[i].addr == msg[i+1].addr) { /* write to then read from same address */ - u8 obuf[3+msg[i].len], ibuf[1+msg[i+1].len]; + u8 obuf[MAX_XFER_SIZE], ibuf[MAX_XFER_SIZE]; + + if (3 + msg[i].len > sizeof(obuf)) { + warn("i2c wr: len=%d is too big!\n", + msg[i].len); + return -EOPNOTSUPP; + } + if (1 + msg[i + 1].len > sizeof(ibuf)) { + warn("i2c rd: len=%d is too big!\n", + msg[i + 1].len); + return -EOPNOTSUPP; + } obuf[0] = msg[i].len; obuf[1] = msg[i+1].len; obuf[2] = msg[i].addr; @@ -191,7 +218,13 @@ static int cxusb_i2c_xfer(struct i2c_adapter *adap, struct i2c_msg msg[], i++; } else { /* write only */ - u8 obuf[2+msg[i].len], ibuf; + u8 obuf[MAX_XFER_SIZE], ibuf; + + if (2 + msg[i].len > sizeof(obuf)) { + warn("i2c wr: len=%d is too big!\n", + msg[i].len); + return -EOPNOTSUPP; + } obuf[0] = msg[i].addr; obuf[1] = msg[i].len; memcpy(&obuf[2], msg[i].buf, msg[i].len); -- 1.8.3.2