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

Ben Hutchings
2018-10-14T23:23:07Z

From: Heinrich Schuchardt <xypron.glpk@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.glpk@gmx.de>
Signed-off-by: Bin Liu <b-liu@ti.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Signed-off-by: Ben Hutchings <ben@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;
}