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SubjectRe: [PATCH v2 1/1] usb: musb: gadget: misplaced out of bounds check
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Hello!

On 3/20/2018 5:27 AM, Heinrich Schuchardt wrote:

> 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;
> }

Please remove the braces, they're not needed anymore.

[...]

MBR, Sergei

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