[PATCH 3.16 184/366] usbip: vhci_hcd: check rhport before using in vhci_hub_control()

[Ben Hutchings]

3.16.60-rc1 review patch.  If anyone has any objections, please let me know.

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

From: Shuah Khan <shua...@osg.samsung.com>

commit 5b22f676118ff25049382041da0db8012e57c9e8 upstream.

Validate !rhport < 0 before using it to access port_status array.

Signed-off-by: Shuah Khan <shua...@osg.samsung.com>
Signed-off-by: Greg Kroah-Hartman <gre...@linuxfoundation.org>
[bwh: Backported to 3.16:
 - Drop changes to the SetPortFeature
   USB_PORT_FEAT_{SUSPEND,POWER,BH_PORT_RESET} cases
 - Add the "error" label
 - Adjust filename, context]
Signed-off-by: Ben Hutchings <b...@decadent.org.uk>
---
--- a/drivers/staging/usbip/vhci_hcd.c
+++ b/drivers/staging/usbip/vhci_hcd.c
@@ -266,6 +266,8 @@ static int vhci_hub_control(struct usb_h
                usbip_dbg_vhci_rh(" ClearHubFeature\n");
                break;
        case ClearPortFeature:
+               if (rhport < 0)
+                       goto error;
                switch (wValue) {
                case USB_PORT_FEAT_SUSPEND:
                        if (dum->port_status[rhport] & USB_PORT_STAT_SUSPEND) {
@@ -370,6 +372,8 @@ static int vhci_hub_control(struct usb_h
                case USB_PORT_FEAT_RESET:
                        usbip_dbg_vhci_rh(
                                " SetPortFeature: USB_PORT_FEAT_RESET\n");
+                       if (rhport < 0)
+                               goto error;
                        /* if it's already running, disconnect first */
                        if (dum->port_status[rhport] & USB_PORT_STAT_ENABLE) {
                                dum->port_status[rhport] &=
@@ -385,6 +389,8 @@ static int vhci_hub_control(struct usb_h
                default:
                        usbip_dbg_vhci_rh(" SetPortFeature: default %d\n",
                                          wValue);
+                       if (rhport < 0)
+                               goto error;
                        dum->port_status[rhport] |= (1 << wValue);
                        break;
                }
@@ -392,7 +398,7 @@ static int vhci_hub_control(struct usb_h
 
        default:
                pr_err("default: no such request\n");
-
+error:
                /* "protocol stall" on error */
                retval = -EPIPE;
        }