Commit b6af5544 authored by Jakob Koschel's avatar Jakob Koschel Committed by Greg Kroah-Hartman
Browse files

usb: gadget: bdc: remove usage of list iterator past the loop body 

If the list representing the request queue does not contain the expected
request, the value of the list_for_each_entry() iterator will not point
to a valid structure. To avoid type confusion in such case, the list
iterator scope will be limited to the list_for_each_entry() loop.

In preparation to limiting scope of the list iterator to the list traversal
loop, use a dedicated pointer to point to the found request object [1].

Link: https://lore.kernel.org/all/YhdfEIwI4EdtHdym@kroah.com/


Signed-off-by: default avatarJakob Koschel <jakobkoschel@gmail.com>
Link: https://lore.kernel.org/r/20220308171818.384491-3-jakobkoschel@gmail.com


Signed-off-by: default avatarGreg Kroah-Hartman <gregkh@linuxfoundation.org>
parent 83888411

drivers/usb/gadget/udc/bdc/bdc_ep.c

+9 −4
Original line number Diff line number Diff line
@@ -1757,6 +1757,7 @@ static int bdc_gadget_ep_dequeue(struct usb_ep *_ep, 
				  struct usb_request *_req)

{

	struct bdc_req *req;

	struct bdc_req *iter;

	unsigned long flags;

	struct bdc_ep *ep;

	struct bdc *bdc;
@@ -1771,12 +1772,16 @@ static int bdc_gadget_ep_dequeue(struct usb_ep *_ep, 
	dev_dbg(bdc->dev, "%s ep:%s req:%p\n", __func__, ep->name, req);

	bdc_dbg_bd_list(bdc, ep);

	spin_lock_irqsave(&bdc->lock, flags);



	req = NULL;

	/* make sure it's still queued on this endpoint */

	list_for_each_entry(req, &ep->queue, queue) {

		if (&req->usb_req == _req)

	list_for_each_entry(iter, &ep->queue, queue) {

		if (&iter->usb_req != _req)

			continue;

		req = iter;

		break;

	}

	if (&req->usb_req != _req) {

	if (!req) {

		spin_unlock_irqrestore(&bdc->lock, flags);

		dev_err(bdc->dev, "usb_req !=req n");

		return -EINVAL;