[PATCH 4.9 45/88] USB: usbtmc: fix probe error path

[Greg Kroah-Hartman]

4.9-stable review patch.  If anyone has any objections, please let me know.

------------------

From: Johan Hovold <johan@xxxxxxxxxx>

commit 2e47c53503eb9faff42b3cfa144a833344dd1f89 upstream.

Make sure to initialise the return value to avoid having allocation
failures going unnoticed when allocating interrupt-endpoint resources.

This prevents use-after-free or worse when the device is later unbound.

Fixes: dbf3e7f654c0 ("Implement an ioctl to support the USMTMC-USB488 READ_STATUS_BYTE operation.")
Cc: Dave Penkler <dpenkler@xxxxxxxxx>
Signed-off-by: Johan Hovold <johan@xxxxxxxxxx>
Signed-off-by: Greg Kroah-Hartman <gregkh@xxxxxxxxxxxxxxxxxxx>

---
 drivers/usb/class/usbtmc.c |    8 ++++++--
 1 file changed, 6 insertions(+), 2 deletions(-)

--- a/drivers/usb/class/usbtmc.c
+++ b/drivers/usb/class/usbtmc.c
@@ -1475,8 +1475,10 @@ static int usbtmc_probe(struct usb_inter
 	if (data->iin_ep_present) {
 		/* allocate int urb */
 		data->iin_urb = usb_alloc_urb(0, GFP_KERNEL);
-		if (!data->iin_urb)
+		if (!data->iin_urb) {
+			retcode = -ENOMEM;
 			goto error_register;
+		}
 
 		/* will reference data in int urb */
 		kref_get(&data->kref);
@@ -1484,8 +1486,10 @@ static int usbtmc_probe(struct usb_inter
 		/* allocate buffer for interrupt in */
 		data->iin_buffer = kmalloc(data->iin_wMaxPacketSize,
 					GFP_KERNEL);
-		if (!data->iin_buffer)
+		if (!data->iin_buffer) {
+			retcode = -ENOMEM;
 			goto error_register;
+		}
 
 		/* fill interrupt urb */
 		usb_fill_int_urb(data->iin_urb, data->usb_dev,