[PATCH 3.16 073/366] usb: musb: gadget: misplaced out of bounds check

[Ben Hutchings]

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

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

From: Heinrich Schuchardt <xypron.g...@gmx.de>

commit af6f8529098aeb0e56a68671b450cf74e7a64fcd upstream.

musb->endpoints[] has array size MUSB_C_NUM_EPS.
We must check array bounds before accessing the array and not afterwards.

Signed-off-by: Heinrich Schuchardt <xypron.g...@gmx.de>
Signed-off-by: Bin Liu <b-...@ti.com>
Signed-off-by: Greg Kroah-Hartman <gre...@linuxfoundation.org>
Signed-off-by: Ben Hutchings <b...@decadent.org.uk>
---
 drivers/usb/musb/musb_gadget_ep0.c | 14 +++++++++-----
 1 file changed, 9 insertions(+), 5 deletions(-)

--- a/drivers/usb/musb/musb_gadget_ep0.c
+++ b/drivers/usb/musb/musb_gadget_ep0.c
@@ -114,15 +114,19 @@ static int service_tx_status_request(
                }
 
                is_in = epnum & USB_DIR_IN;
-               if (is_in) {
-                       epnum &= 0x0f;
+               epnum &= 0x0f;
+               if (epnum >= MUSB_C_NUM_EPS) {
+                       handled = -EINVAL;
+                       break;
+               }
+
+               if (is_in)
                        ep = &musb->endpoints[epnum].ep_in;
-               } else {
+               else
                        ep = &musb->endpoints[epnum].ep_out;
-               }
                regs = musb->endpoints[epnum].regs;
 
-               if (epnum >= MUSB_C_NUM_EPS || !ep->desc) {
+               if (!ep->desc) {
                        handled = -EINVAL;
                        break;
                }