Patch "USB: serial: quatech2: fix control-message error handling" has been added to the 4.9-stable tree

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

USB: serial: quatech2: fix control-message error handling

to the 4.9-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:
usb-serial-quatech2-fix-control-message-error-handling.patch
and it can be found in the queue-4.9 subdirectory.

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

From: Johan Hovold <[email protected]>
Date: Thu, 12 Jan 2017 14:56:20 +0100
Subject: USB: serial: quatech2: fix control-message error handling

From: Johan Hovold <[email protected]>

commit 8c34cb8ddfe808d557b51da983ff10c02793beb2 upstream.

Make sure to detect short control-message transfers when fetching modem and line state in open and when retrieving registers.

This specifically makes sure that an errno is returned to user space on errors in TIOCMGET instead of a zero bitmask.

Also drop the unused getdevice function which also lacked appropriate error handling.

---
 drivers/usb/serial/quatech2.c |   24 +++++++++++++-----------
 1 file changed, 13 insertions(+), 11 deletions(-)

@@ -188,22 +188,22 @@ static inline int qt2_setdevice(struct u
 }
 
 
-static inline int qt2_getdevice(struct usb_device *dev, u8 *data)
-{
-	return usb_control_msg(dev, usb_rcvctrlpipe(dev, 0),
-			       QT_SET_GET_DEVICE, 0xc0, 0, 0,
-			       data, 3, QT2_USB_TIMEOUT);
-}
-
 static inline int qt2_getregister(struct usb_device *dev,
 				  u8 uart,
 				  u8 reg,
 				  u8 *data)
 {
-	return usb_control_msg(dev, usb_rcvctrlpipe(dev, 0),
-			       QT_SET_GET_REGISTER, 0xc0, reg,
-			       uart, data, sizeof(*data), QT2_USB_TIMEOUT);
+	int ret;
 
+	ret = usb_control_msg(dev, usb_rcvctrlpipe(dev, 0),
+			      QT_SET_GET_REGISTER, 0xc0, reg,
+			      uart, data, sizeof(*data), QT2_USB_TIMEOUT);
+	if (ret < sizeof(*data)) {
+		if (ret >= 0)
+			ret = -EIO;
+	}
+
+	return ret;
 }
 
 static inline int qt2_setregister(struct usb_device *dev,

@@ -372,9 +372,11 @@ static int qt2_open(struct tty_struct *t
 				 0xc0, 0,
 				 device_port, data, 2, QT2_USB_TIMEOUT);
 
-	if (status < 0) {
+	if (status < 2) {
 		dev_err(&port->dev, "%s - open port failed %i\n", __func__,
 			status);
+		if (status >= 0)
+			status = -EIO;
 		kfree(data);
 		return status;
 	}

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

queue-4.9/usb-serial-mct_u232-fix-modem-status-error-handling.patch queue-4.9/usb-serial-ark3116-fix-open-error-handling.patch queue-4.9/usb-serial-io_edgeport-fix-epic-descriptor-handling.patch queue-4.9/usb-serial-ti_usb_3410_5052-fix-control-message-error-handling.patch queue-4.9/usb-serial-keyspan_pda-fix-receive-sanity-checks.patch queue-4.9/usb-serial-sierra-fix-bogus-alternate-setting-assumption.patch queue-4.9/usb-serial-ssu100-fix-control-message-error-handling.patch queue-4.9/usb-serial-digi_acceleport-fix-incomplete-rx-sanity-check.patch queue-4.9/usb-serial-io_edgeport-fix-descriptor-error-handling.patch queue-4.9/usb-serial-quatech2-fix-control-message-error-handling.patch queue-4.9/usb-serial-ftdi_sio-fix-latency-timer-error-handling.patch