Patch "[media] rtl28xxu: fix control message flaws" has been added to the 4.2-stable tree

Patch "[media] rtl28xxu: fix control message flaws" has been added to the 4.2-stable tree

[gregkh]

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

    [media] rtl28xxu: fix control message flaws

to the 4.2-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:
     rtl28xxu-fix-control-message-flaws.patch
and it can be found in the queue-4.2 subdirectory.

If you, or anyone else, feels it should not be added to the stable tree,
please let <stable@vger.kernel.org> know about it.


>From d18ca5b7ceca0e9674cb4bb2ed476b0fcbb23ba2 Mon Sep 17 00:00:00 2001
From: Antti Palosaari <crope@iki.fi>
Date: Tue, 6 Oct 2015 00:22:23 -0300
Subject: [media] rtl28xxu: fix control message flaws

From: Antti Palosaari <crope@iki.fi>

commit d18ca5b7ceca0e9674cb4bb2ed476b0fcbb23ba2 upstream.

Add lock to prevent concurrent access for control message as control
message function uses shared buffer. Without the lock there may be
remote control polling which messes the buffer causing IO errors.
Increase buffer size and add check for maximum supported message
length.

Link: https://bugzilla.kernel.org/show_bug.cgi?id=103391
Fixes: c56222a6b25c ("[media] rtl28xxu: move usb buffers to state")

Signed-off-by: Antti Palosaari <crope@iki.fi>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

---
 drivers/media/usb/dvb-usb-v2/rtl28xxu.c |   15 +++++++++++++--
 drivers/media/usb/dvb-usb-v2/rtl28xxu.h |    2 +-
 2 files changed, 14 insertions(+), 3 deletions(-)

--- a/drivers/media/usb/dvb-usb-v2/rtl28xxu.c
+++ b/drivers/media/usb/dvb-usb-v2/rtl28xxu.c
@@ -34,6 +34,14 @@ static int rtl28xxu_ctrl_msg(struct dvb_
 	unsigned int pipe;
 	u8 requesttype;
 
+	mutex_lock(&d->usb_mutex);
+
+	if (req->size > sizeof(dev->buf)) {
+		dev_err(&d->intf->dev, "too large message %u\n", req->size);
+		ret = -EINVAL;
+		goto err_mutex_unlock;
+	}
+
 	if (req->index & CMD_WR_FLAG) {
 		/* write */
 		memcpy(dev->buf, req->data, req->size);
@@ -50,14 +58,17 @@ static int rtl28xxu_ctrl_msg(struct dvb_
 	dvb_usb_dbg_usb_control_msg(d->udev, 0, requesttype, req->value,
 			req->index, dev->buf, req->size);
 	if (ret < 0)
-		goto err;
+		goto err_mutex_unlock;
 
 	/* read request, copy returned data to return buf */
 	if (requesttype == (USB_TYPE_VENDOR | USB_DIR_IN))
 		memcpy(req->data, dev->buf, req->size);
 
+	mutex_unlock(&d->usb_mutex);
+
 	return 0;
-err:
+err_mutex_unlock:
+	mutex_unlock(&d->usb_mutex);
 	dev_dbg(&d->intf->dev, "failed=%d\n", ret);
 	return ret;
 }
--- a/drivers/media/usb/dvb-usb-v2/rtl28xxu.h
+++ b/drivers/media/usb/dvb-usb-v2/rtl28xxu.h
@@ -71,7 +71,7 @@
 
 
 struct rtl28xxu_dev {
-	u8 buf[28];
+	u8 buf[128];
 	u8 chip_id;
 	u8 tuner;
 	char *tuner_name;


Patches currently in stable-queue which might be from crope@iki.fi are

queue-4.2/si2168-bounds-check-firmware.patch
queue-4.2/rtl28xxu-fix-control-message-flaws.patch
queue-4.2/m88ds3103-use-own-reg-update_bits-implementation.patch