patch "USB: serial: ark3116: fix register-accessor error handling" added to usb-testing

[<gregkh@linuxfoundation.org>]

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

    USB: serial: ark3116: fix register-accessor error handling

to my usb git tree which can be found at
    git://git.kernel.org/pub/scm/linux/kernel/git/gregkh/usb.git
in the usb-testing branch.

The patch will show up in the next release of the linux-next tree
(usually sometime within the next 24 hours during the week.)

The patch will be merged to the usb-next branch sometime soon,
after it passes testing, and the merge window is open.

If you have any questions about this process, please let me know.


>From 9fef37d7cf170522fb354d6d0ea6de09b9b16678 Mon Sep 17 00:00:00 2001
From: Johan Hovold <johan@kernel.org>
Date: Thu, 12 Jan 2017 14:56:09 +0100
Subject: USB: serial: ark3116: fix register-accessor error handling

The current implementation failed to detect short transfers, something
which could lead to bits of the uninitialised heap transfer buffer
leaking to user space.

Fixes: 149fc791a452 ("USB: ark3116: Setup some basic infrastructure for
new ark3116 driver.")
Fixes: f4c1e8d597d1 ("USB: ark3116: Make existing functions 16450-aware
and add close and release functions.")
Cc: stable <stable@vger.kernel.org>
Reviewed-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Signed-off-by: Johan Hovold <johan@kernel.org>
---
 drivers/usb/serial/ark3116.c | 13 ++++++++++---
 1 file changed, 10 insertions(+), 3 deletions(-)

diff --git a/drivers/usb/serial/ark3116.c b/drivers/usb/serial/ark3116.c
index 1532cde8a437..7812052dc700 100644
--- a/drivers/usb/serial/ark3116.c
+++ b/drivers/usb/serial/ark3116.c
@@ -99,10 +99,17 @@ static int ark3116_read_reg(struct usb_serial *serial,
 				 usb_rcvctrlpipe(serial->dev, 0),
 				 0xfe, 0xc0, 0, reg,
 				 buf, 1, ARK_TIMEOUT);
-	if (result < 0)
+	if (result < 1) {
+		dev_err(&serial->interface->dev,
+				"failed to read register %u: %d\n",
+				reg, result);
+		if (result >= 0)
+			result = -EIO;
+
 		return result;
-	else
-		return buf[0];
+	}
+
+	return buf[0];
 }
 
 static inline int calc_divisor(int bps)
-- 
2.11.1