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Subject[PATCH v2 1/1] usb: musb: gadget: misplaced out of bounds check
Date
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>
---
v2
Only the 4 low bits of epnum are relevant for indexing.
---
drivers/usb/musb/musb_gadget_ep0.c | 9 +++++++--
1 file changed, 7 insertions(+), 2 deletions(-)

diff --git a/drivers/usb/musb/musb_gadget_ep0.c b/drivers/usb/musb/musb_gadget_ep0.c
index 18da4873e52e..96b0fa12f729 100644
--- a/drivers/usb/musb/musb_gadget_ep0.c
+++ b/drivers/usb/musb/musb_gadget_ep0.c
@@ -89,15 +89,20 @@ static int service_tx_status_request(
}

is_in = epnum & USB_DIR_IN;
+ epnum &= 0x0f;
+ if (epnum >= MUSB_C_NUM_EPS) {
+ handled = -EINVAL;
+ break;
+ }
+
if (is_in) {
- epnum &= 0x0f;
ep = &musb->endpoints[epnum].ep_in;
} 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;
}
--
2.16.2
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