[3.11.y.z extended stable] Patch "[media] mxl111sf: Don't use dynamic static allocation" has been added to staging queue

[Luis Henriques]

This is a note to let you know that I have just added a patch titled

    [media] mxl111sf: 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 d08767078f2ec9115d5ebb7861285013e70350b7 Mon Sep 17 00:00:00 2001
From: Mauro Carvalho Chehab <m.chehab at samsung.com>
Date: Sat, 2 Nov 2013 08:13:02 -0300
Subject: [media] mxl111sf: Don't use dynamic static allocation

commit c98300a0e8cf160aaea60bc05d2cd156a7666173 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-v2/mxl111sf.c:74:1: warning: 'mxl111sf_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 at samsung.com>
Reviewed-by: Hans Verkuil <hans.verkuil at cisco.com>
Signed-off-by: Mauro Carvalho Chehab <m.chehab at samsung.com>
Signed-off-by: Luis Henriques <luis.henriques at canonical.com>
---
 drivers/media/usb/dvb-usb-v2/mxl111sf.c | 10 +++++++++-
 1 file changed, 9 insertions(+), 1 deletion(-)

diff --git a/drivers/media/usb/dvb-usb-v2/mxl111sf.c b/drivers/media/usb/dvb-usb-v2/mxl111sf.c
index e97964e..2627553 100644
--- a/drivers/media/usb/dvb-usb-v2/mxl111sf.c
+++ b/drivers/media/usb/dvb-usb-v2/mxl111sf.c
@@ -23,6 +23,9 @@
 #include "lgdt3305.h"
 #include "lg2160.h"

+/* Max transfer size done by I2C transfer functions */
+#define MAX_XFER_SIZE  64
+
 int dvb_usb_mxl111sf_debug;
 module_param_named(debug, dvb_usb_mxl111sf_debug, int, 0644);
 MODULE_PARM_DESC(debug, "set debugging level "
@@ -57,7 +60,12 @@ int mxl111sf_ctrl_msg(struct dvb_usb_device *d,
 {
 	int wo = (rbuf == NULL || rlen == 0); /* write-only */
 	int ret;
-	u8 sndbuf[1+wlen];
+	u8 sndbuf[MAX_XFER_SIZE];
+
+	if (1 + wlen > sizeof(sndbuf)) {
+		pr_warn("%s: len=%d is too big!\n", __func__, wlen);
+		return -EOPNOTSUPP;
+	}

 	pr_debug("%s(wlen = %d, rlen = %d)\n", __func__, wlen, rlen);

--
1.8.3.2