Patch "[media] cx24116: fix a buffer overflow when checking userspace params" has been added to the 4.1-stable tree

This is a note to let you know that I've just added the patch titled

[media] cx24116: fix a buffer overflow when checking userspace params

to the 4.1-stable tree which can be found at:
http://www.kernel.org/git/?p=linux/kernel/git/stable/stable-queue.git;a=summary

The filename of the patch is:
cx24116-fix-a-buffer-overflow-when-checking-userspace-params.patch
and it can be found in the queue-4.1 subdirectory.

If you, or anyone else, feels it should not be added to the stable tree, please let <[email protected]> know about it.

From: Mauro Carvalho Chehab <[email protected]>
Date: Tue, 28 Apr 2015 18:51:17 -0300
Subject: [media] cx24116: fix a buffer overflow when checking userspace params

From: Mauro Carvalho Chehab <[email protected]>

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

---
 drivers/media/dvb-frontends/cx24116.c |    8 ++++----
 1 file changed, 4 insertions(+), 4 deletions(-)

@@ -963,6 +963,10 @@ static int cx24116_send_diseqc_msg(struc
 	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(struc
 		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];

Patches currently in stable-queue which might be from [email protected] are

queue-4.1/media-fix-regression-in-some-more-dib0700-based-devices.patch queue-4.1/cx24116-fix-a-buffer-overflow-when-checking-userspace-params.patch queue-4.1/saa7164-fix-querycap-warning.patch queue-4.1/vb2-don-t-warn-when-v4l2_buffer.bytesused-is-0-for-multiplanar-buffers.patch queue-4.1/s5h1420-fix-a-buffer-overflow-when-checking-userspace-params.patch queue-4.1/rc-core-fix-dib0700-scancode-generation-for-rc5.patch queue-4.1/cx24117-fix-a-buffer-overflow-when-checking-userspace-params.patch queue-4.1/af9013-don-t-accept-invalid-bandwidth.patch queue-4.1/cx18-add-missing-caps-for-the-pcm-video-device.patch