From: Johan Hovold <johan@hovoldconsulting.com>
Date: Wed, 17 Feb 2016 18:30:40 +0000 (+0100)
Subject: greybus: es2: fix cport-count error handling
X-Git-Tag: v5.15~12752^2~378^2~21^2~675
X-Git-Url: http://review.tizen.org/git/?a=commitdiff_plain;h=478ce7203c2cf3f241f11587717336a60d391269;p=platform%2Fkernel%2Flinux-starfive.git

greybus: es2: fix cport-count error handling

Make sure to check for short transfers when retrieving the bridge cport
count.

Also clear the request buffer when allocating it.

Signed-off-by: Johan Hovold <johan@hovoldconsulting.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@google.com>
---

diff --git a/drivers/staging/greybus/es2.c b/drivers/staging/greybus/es2.c
index e39bd58..5ade51e 100644
--- a/drivers/staging/greybus/es2.c
+++ b/drivers/staging/greybus/es2.c
@@ -861,7 +861,7 @@ static int apb_get_cport_count(struct usb_device *udev)
 	int retval;
 	__le16 *cport_count;
 
-	cport_count = kmalloc(sizeof(*cport_count), GFP_KERNEL);
+	cport_count = kzalloc(sizeof(*cport_count), GFP_KERNEL);
 	if (!cport_count)
 		return -ENOMEM;
 
@@ -870,9 +870,13 @@ static int apb_get_cport_count(struct usb_device *udev)
 				 USB_DIR_IN | USB_TYPE_VENDOR |
 				 USB_RECIP_INTERFACE, 0, 0, cport_count,
 				 sizeof(*cport_count), ES2_TIMEOUT);
-	if (retval < 0) {
+	if (retval != sizeof(*cport_count)) {
 		dev_err(&udev->dev, "Cannot retrieve CPort count: %d\n",
 			retval);
+
+		if (retval >= 0)
+			retval = -EIO;
+
 		goto out;
 	}