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[3.11.y.z,extended,stable] Patch "[media] cxusb: Don't use dynamic static allocation" has been added to staging queue

Message ID 1386242671-1752-1-git-send-email-luis.henriques@canonical.com
State New
Headers show

Commit Message

Luis Henriques Dec. 5, 2013, 11:24 a.m. UTC
This is a note to let you know that I have just added a patch titled

    [media] cxusb: Don't use dynamic static allocation

to the linux-3.11.y-queue branch of the 3.11.y.z extended stable tree 
which can be found at:

 http://kernel.ubuntu.com/git?p=ubuntu/linux.git;a=shortlog;h=refs/heads/linux-3.11.y-queue

If you, or anyone else, feels it should not be added to this tree, please 
reply to this email.

For more information about the 3.11.y.z tree, see
https://wiki.ubuntu.com/Kernel/Dev/ExtendedStable

Thanks.
-Luis

------

From 6fd1d5e1f4df1ad8e7b6ad50434c68be918f0ebe Mon Sep 17 00:00:00 2001
From: Mauro Carvalho Chehab <m.chehab@samsung.com>
Date: Sat, 2 Nov 2013 07:18:09 -0300
Subject: [media] cxusb: Don't use dynamic static allocation

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 <m.chehab@samsung.com>
Reviewed-by: Hans Verkuil <hans.verkuil@cisco.com>
Signed-off-by: Mauro Carvalho Chehab <m.chehab@samsung.com>
Signed-off-by: Luis Henriques <luis.henriques@canonical.com>
---
 drivers/media/usb/dvb-usb/cxusb.c | 41 +++++++++++++++++++++++++++++++++++----
 1 file changed, 37 insertions(+), 4 deletions(-)

--
1.8.3.2
diff mbox

Patch

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);